Atmel-46004B-SE-M90E36A-Datasheet_021215
FEATURES
Metering Features
•Metering features fully in compliance with the requirements of IEC62052-11,
IEC62053-22 and IEC62053-23, ANSI C12.1 and ANSI C12.20; applicable in class
0.2S, 0.5S or class 1 poly-phase watt-hour meter or class 2 poly-phase var-hour
meter.
•Accuracy of ±0.1% for active energy and ±0.2% for reactive energy over the
dynamic range of 6000:1.
•Temperature coefficient is 6 ppm/ ℃ (typical) for on-chip reference voltage.
•Single-point calibration on each phase over the whole dynamic range for active
energy; no calibration needed for reactive/apparent energy.
•±1℃ (typical) temperature sensor accuracy.
•Electrical parameters measurement: less than ±0.5% fiducial error for Vrms, Irms,
mean active/ reactive/ apparent power, frequency, power factor and phase angle.
•Active (forward/reverse), reactive (forward/reverse), apparent energy with indepen-
dent energy registers. Active/ reactive/ apparent energy can be output by pulse or
read through energy registers to adapt to different applications.
•Programmable startup and no-load power threshold, special designed of startup
and no-load circuits to eliminate crosstalk among phases achieving better accuracy
especially at low power conditions.
•Dedicated ADC and different gains for phase A/B/C and Neutral line current sam-
pling circuits. Current sampled over current transformer (CT) or Rogowski coil (di/dt
coil); phase A/B/C voltage sampled over resistor divider network or potential trans-
former (PT).
•Programmable power modes: Normal mode (N mode), Idle mode (I mode), Detec-
tion mode (D mode) and Partial Measurement mode (M mode).
•Fundamental (CF3, 0.2%) and harmonic (CF4, 1%) active energy with dedicated
energy and power registers.
•Total Harmonic Distortion (THD) and Discrete Fourier Transform (DFT) functions for
2 ~ 32 order harmonic component. THD and DFT results available in SPI accessible
registers. Both voltage and current of all phases processed within the same time
period.
•Event detection: sag, phase loss, reverse voltage/ current phase sequence, reverse
flow, calculated neutral line current INC overcurrent sampled neutral line current INS
overcurrent and THD+N over-threshold.
Other Features
•3.3V single power supply. Operating voltage range: 2.8V~3.6V. Metering accuracy
guaranteed within 3.0V~3.6V.
•Four-wire SPI interface with Direct Memory Access (DMA) mode to stream out 7-
channel ADC raw data.
•Parameter diagnosis function and programmable interrupt output of the IRQ inter-
Atmel M90E36A
Enhanced Poly-Phase High-Performance Wide-Span
Energy Metering IC
DATASHEET
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
2
rupt signals and the WarnOut signal.
•Programmable voltage sag detection and zero-crossing output.
•CF1/CF2/CF3/CF4 output active/ reactive/ apparent energy pulses and fundamental/ harmonic energy pulses
respectively.
•Crystal oscillator frequency: 16.384 MHz. On-chip two capacitors and no need of external capacitors.
•TQFP48 package.
•Operating temperature: -40 ℃ ~ +85 ℃.
APPLICATION
•Poly-phase energy meters of class 0.2S, 0.5S and class 1 which are used in three-phase four-wire (3P4W, Y0) or
three-phase three-wire (3P3W, Y or Δ) systems.
•Data Acquisition Terminal.
•Power monitoring instruments which need to measure voltage, current, THD, DFT, mean power, etc.
GENERAL DESCRIPTION
The M90E36A is a poly-phase high performance wide-dynamic range metering IC. The M90E36A incorporates 7 indepen-
dent 2nd order sigma-delta ADCs, which could be employed in three voltage channels (phase A, B and C) and four current
channels (phase A, B, C and neutral line) in a typical three-phase four-wire system.
The M90E36A has an embedded DSP which executes calculation of active energy, reactive energy, apparent energy, fun-
damental and harmonic active energy over ADC signal and on-chip reference voltage. The DSP also calculates measure-
ment parameters such as voltage and current RMS value as well as mean active/reactive/apparent power.
A four-wire SPI interface is provided between the M90E36A and the external microcontroller. In addition, DMA mode can
be used for 7-channel ADC raw data access, offering more flexibility in system application.
The M90E36A is suitable for poly-phase multi-function meters which could measure active/reactive/apparent energy and
fundamental/harmonic energy either through four independent energy pulse outputs CF1/CF2/CF3/CF4 or through the cor-
responding registers.
With the on-chip THD and DFT engine, all phases' THD and DFT results can be directly accessed through related regis-
ters, thus simplifying hardware design in Data Acquisition Terminals.
The proprietary ADC and auto-temperature compensation technology for reference voltage ensure the M90E36A's long-
term stability over variations in grid and ambient environment conditions.
3
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
BLOCK DIAGRAM
Figure-1 M90E36A Block Diagram
VDD18 Regulator
Temperature Sensor
Current Detector
ADC-V1
ADC-V2
ADC-V3
ADC-I1
ADC-I2
ADC-I3
ADC-IN
SPI Interface
DSP
Energy Metering
(Forward/Reverse
Active/Reactive/CF Generator)
Measure and Monitoring
(V/I/rms / SAG / Phase /
Frequency)
Signal Analyzer
ADC Sample Capture / THD
Control Logic
Zero
Crossing
CF Out
Power On Reset Crystal Oscillator
DMA
Reference Voltage Vref
I1P / I1N
V1P / V1N
CS
SCLK
SDO
SDI
OSCI OSCO
RESET
CF1
ZX0
I2P / I2N
I3P / I3N
V2P / V2N
V3P / V3N
I4P / I4N
CF2
CF3
CF4
ZX1
ZX2
Power Mode
Configuration
PM1
PM0
WarnOut
IRQ0
IRQ1
DMA_CTRL
IRQ
Warn
Out
4
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
FEATURES .......................................................................................................................................... 1
APPLICATION ..................................................................................................................................... 2
GENERAL DESCRIPTION................................................................................................................... 2
BLOCK DIAGRAM............................................................................................................................... 3
1 PIN ASSIGNMENT .......................................................................................................................... 8
2 PIN DESCRIPTION .......................................................................................................................... 9
3 FUNCTION DESCRIPTION ........................................................................................................... 11
3.1 POWER SUPPLY ...................................................................................................................................................11
3.2 CLOCK ...................................................................................................................................................................11
3.3 RESET ....................................................................................................................................................................11
3.3.1 RESET Pin .................................................................................................................................................. 11
3.3.2 Power On Reset (POR) ............................................................................................................................. 11
3.3.3 Software Reset .......................................................................................................................................... 11
3.4 METERING FUNCTION .........................................................................................................................................12
3.4.1 Theory of Energy Registers ..................................................................................................................... 12
3.4.2 Energy Registers ....................................................................................................................................... 14
3.4.3 Energy Pulse Output ................................................................................................................................. 14
3.4.4 Startup and No-load Power ...................................................................................................................... 15
3.5 MEASUREMENT FUNCTION ................................................................................................................................16
3.5.1 Active/ Reactive/ Apparent Power ........................................................................................................... 16
3.5.2 Fundamental / Harmonic Active Power ................................................................................................... 16
3.5.3 Mean Power Factor (PF) ........................................................................................................................... 16
3.5.4 Voltage / Current RMS .............................................................................................................................. 16
3.5.5 Phase Angle ............................................................................................................................................... 17
3.5.6 Frequency .................................................................................................................................................. 17
3.5.7 Temperature .............................................................................................................................................. 17
3.5.8 THD+N for Voltage and Current ............................................................................................................... 17
3.6 FOURIER ANALYSIS FUNCTION .........................................................................................................................18
3.7 POWER MODE ......................................................................................................................................................19
3.7.1 Normal Mode (N Mode) ............................................................................................................................. 19
3.7.2 Idle Mode (I Mode) ..................................................................................................................................... 20
3.7.3 Detection Mode (D Mode) ......................................................................................................................... 22
3.7.4 Partial Measurement mode (M Mode) ...................................................................................................... 23
3.7.5 Transition of Power Modes ...................................................................................................................... 24
3.8 EVENT DETECTION ..............................................................................................................................................25
3.8.1 Zero-Crossing Detection .......................................................................................................................... 25
3.8.2 Sag Detection ............................................................................................................................................ 25
3.8.3 Phase Loss Detection ............................................................................................................................... 25
3.8.4 Neutral Line Overcurrent Detection ........................................................................................................ 25
3.8.5 Phase Sequence Error Detection ............................................................................................................ 25
3.9 DC AND CURRENT RMS ESTIMATION ...............................................................................................................25
4 SPI / DMA INTERFACE ................................................................................................................. 26
4.1 INTERFACE DESCRIPTION .................................................................................................................................26
4.2 SLAVE MODE: SPI INTERFACE ..........................................................................................................................27
4.2.1 SPI Slave Interface Format ....................................................................................................................... 27
4.2.2 Reliability Enhancement Feature ............................................................................................................. 28
Table of Contents
5
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
4.3 MASTER MODE: DMA ..........................................................................................................................................28
4.3.1 DMA Burst Transfer for ADC Sampling .................................................................................................. 28
4.3.2 Control Sequence for External Device .................................................................................................... 30
5 CALIBRATION METHOD .............................................................................................................. 31
5.1 NORMAL MODE OPERATION CALIBRATION ....................................................................................................31
5.2 PARTIAL MEASUREMENT MODE CALIBRATION .............................................................................................31
6 REGISTER ..................................................................................................................................... 32
6.1 REGISTER LIST ....................................................................................................................................................32
6.2 SPECIAL REGISTERS ..........................................................................................................................................40
6.2.1 Soft Reset Register ................................................................................................................................... 40
6.2.2 IRQ and WarnOut Signal Generation ...................................................................................................... 40
6.2.3 Special Configuration Registers .............................................................................................................. 45
6.2.4 Last SPI Data Register .............................................................................................................................. 48
6.3 LOW-POWER MODES REGISTERS ....................................................................................................................49
6.3.1 Detection Mode Registers ........................................................................................................................ 49
6.3.2 Partial Measurement mode Registers ..................................................................................................... 52
6.4 CONFIGURATION AND CALIBRATION REGISTERS .........................................................................................55
6.4.1 Start Registers and Associated Checksum Operation Scheme ........................................................... 55
6.4.2 Configuration Registers ........................................................................................................................... 56
6.4.3 Energy Calibration Registers ................................................................................................................... 61
6.4.4 Fundamental/Harmonic Energy Calibration registers ........................................................................... 63
6.4.5 Measurement Calibration ......................................................................................................................... 64
6.5 ENERGY REGISTER .............................................................................................................................................65
6.5.1 Regular Energy Registers ........................................................................................................................ 65
6.5.2 Fundamental / Harmonic Energy Register .............................................................................................. 67
6.6 MEASUREMENT REGISTERS ..............................................................................................................................68
6.6.1 Power and Power Factor Registers ......................................................................................................... 68
6.6.2 Fundamental/ Harmonic Power and Voltage/ Current RMS Registers ................................................. 69
6.6.3 THD+N, Frequency, Angle and Temperature Registers ........................................................................ 70
6.7 HARMONIC FOURIER ANALYSIS REGISTERS ..................................................................................................71
7 ELECTRICAL SPECIFICATION .................................................................................................... 73
7.1 ELECTRICAL SPECIFICATION ............................................................................................................................73
7.2 METERING/ MEASUREMENT ACCURACY .........................................................................................................75
7.2.1 Metering Accuracy .................................................................................................................................... 75
7.2.2 Measurement Accuracy ............................................................................................................................ 76
7.3 INTERFACE TIMING .............................................................................................................................................78
7.3.1 SPI Interface Timing (Slave Mode) .......................................................................................................... 78
7.3.2 DMA Timing (Master Mode) ...................................................................................................................... 79
7.4 POWER ON RESET TIMING .................................................................................................................................80
7.5 ZERO-CROSSING TIMING ....................................................................................................................................81
7.6 VOLTAGE SAG AND PHASE LOSS TIMING .......................................................................................................82
7.7 ABSOLUTE MAXIMUM RATING ..........................................................................................................................83
ORDERING INFORMATION .............................................................................................................. 84
PACKAGE DIMENSIONS .................................................................................................................. 85
REVISION HISTORY ......................................................................................................................... 86
6
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
Table-1 Pin Description ....................................................................................................................................................... 9
Table-2 Power Mode Mapping .......................................................................................................................................... 19
Table-3 Digital I/O and Power Pin States in Idle Mode ..................................................................................................... 21
Table-4 Register List ......................................................................................................................................................... 32
Table-5 Configuration Registers ........................................................................................................................................ 56
Table-6 Calibration Registers ............................................................................................................................................ 61
Table-7 Fundamental/Harmonic Energy Calibration Registers ......................................................................................... 63
Table-8 Measurement Calibration Registers ..................................................................................................................... 64
Table-9 Regular Energy Registers .................................................................................................................................... 65
Table-10 Fundamental / Harmonic Energy Register ......................................................................................................... 67
Table-11 Power and Power Factor Register ..................................................................................................................... 68
Table-12 Fundamental/ Harmonic Power and Voltage/ Current RMS Registers .............................................................. 69
Table-13 THD+N, Frequency, Angle and Temperature Registers .................................................................................... 70
Table-14 Harmonic Fourier Analysis Results Registers .................................................................................................... 71
Table-15 Measurement Parameter Range and Format ..................................................................................................... 76
Table-16 SPI Timing Specification .................................................................................................................................... 78
Table-17 DMA Timing Specification .................................................................................................................................. 79
Table-18 Power On Reset Specification ............................................................................................................................ 80
Table-19 Zero-Crossing Specification ............................................................................................................................... 81
List of Tables
7
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
Figure-1 M90E36A Block Diagram ...................................................................................................................................... 3
Figure-2 Pin Assignment (Top View) ................................................................................................................................... 8
Figure-3 Energy Register Operation Diagram ................................................................................................................... 13
Figure-4 CFx Pulse Output Regulation .............................................................................................................................. 14
Figure-5 Metering Startup Handling .................................................................................................................................. 15
Figure-6 Analysis Function ................................................................................................................................................ 18
Figure-7 Block Diagram in Normal Mode .......................................................................................................................... 19
Figure-8 Block Diagram in Idle Mode ................................................................................................................................ 20
Figure-9 Block Diagram in Detection Mode ....................................................................................................................... 22
Figure-10 Block Diagram in Partial Measurement Mode ................................................................................................... 23
Figure-11 Power Mode Transition ..................................................................................................................................... 24
Figure-12 Slave Mode ....................................................................................................................................................... 26
Figure-13 Master Mode (PIN_DIR_SEL=0) ....................................................................................................................... 26
Figure-14 Read Sequence ................................................................................................................................................ 27
Figure-15 Write Sequence ................................................................................................................................................. 27
Figure-16 Clock Mode0 (CLK_DRV=0, CLK_IDLE=0) and Mode1 (CLK_DRV=0, CLK_IDLE=1) .................................... 29
Figure-17 Clock Mode2 (CLK_DRV=1, CLK_IDLE=0) and Mode3 (CLK_DRV=1, CLK_IDLE=1) .................................... 29
Figure-18 Sample Sequence Example .............................................................................................................................. 30
Figure-19 Sample Bit Sequence Example ......................................................................................................................... 30
Figure-20 IRQ and WarnOut Generation ........................................................................................................................... 40
Figure-21 Current Detection Register Latching Scheme ................................................................................................... 49
Figure-22 Start and Checksum Register Operation Scheme ............................................................................................ 55
Figure-23 SPI Timing Diagram .......................................................................................................................................... 78
Figure-24 DMA Timing Diagram ........................................................................................................................................ 79
Figure-25 Power On Reset Timing (M90E36A and MCU are Powered on Simultaneously) ............................................. 80
Figure-26 Power On Reset Timing in Normal & Partial Measurement Mode .................................................................... 80
Figure-27 Zero-Crossing Timing Diagram (per phase) ...................................................................................................... 81
Figure-28 Voltage Sag and Phase Loss Timing Diagram ................................................................................................. 82
List of Figures
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
8
1 PIN ASSIGNMENT
Figure-2 Pin Assignment (Top View)
1
2
3
4
5
6
8
9
10
11
13
25
AVDD
AGND
I1P
I1N
I2P
I2N
V1P
V1N
Vref
AGND
WarnOut
CS
TEST
NC
DM A_CTRL
PM0
SCLK
CF1
CF2
ZX0
IRQ0
7
12
14
15
16
17
18
19
20
21
22
23
24
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
I3P
I3N
I4P
I4N
V2P
V2N
V3P
V3N
DGND
OSCI
OSCO
ZX1
ZX2
CF3
CF4
IRQ1
PM1
SDO
SDI
RESET
VDD18
VDD18
DGND
NC
NC
DGND
DVDD
9
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
2 PIN DESCRIPTION
Table-1 Pin Description
Name Pin No. I/O Type Description
Reset 41 I LVTTL
Reset: Reset Pin (active low)
This pin should connect to ground through a 0.1 μF filter capacitor and a
10kΩ resistor to VDD. In application it can also directly connect to one out-
put pin from microcontroller (MCU).
AVDD 1 I Power
AVDD: Analog Power Supply
This pin provides power supply to the analog part. This pin should connect
to DVDD and be decoupled with a 0.1μF capacitor.
DVDD 48 I Power
DVDD: Digital Power Supply
This pin provides power supply to the digital part. It should be decoupled
with a 10μF capacitor and a 0.1μF capacitor.
VDD18 42, 43 P Power
VDD18: Digital Power Supply (1.8 V)
These two pins should be connected together and connected to ground
through a 10μF capacitor.
DGND 19, 44, 47 I Power DGND: Digital Ground
AGND 2, 12 I Power AGND: Analog Ground
I1P
I1N
3
4I Analog
I1P: Positive Input for Phase A Current
I1N: Negative Input for Phase A Current
These pins are differential inputs for phase A current.
Note: I1 to phase A and I3 to phase C mapping can be swapped by configur-
ing the I1I3Swap bit (b13, MMode0).
I2P
I2N
5
6I Analog
I2P: Positive Input for Phase B Current
I2N: Negative Input for Phase B Current
These pins are differential inputs for phase B current.
I3P
I3N
7
8I Analog
I3P: Positive Input for Phase C Current
I3N: Negative Input for Phase C Current
These pins are differential inputs for phase C current.
Note: I1 to phase A and I3 to phase C mapping can be swapped by configur-
ing the I1I3Swap bit (b13, MMode0).
I4P
I4N
9
10 I Analog
I4P: Positive Input for N Line Current
I4N: Negative Input for N Line Current
These pins are differential inputs for N line current.
Vref 11 O Analog
Vref: Output Pin for Reference Voltage
This pin should be decoupled with a 10μF capacitor, possibly a 0.1μF
ceramic capacitor and a 1nF ceramic capacitor.
V1P
V1N
13
14 I Analog
V1P: Positive Input for Phase A Voltage
V1N: Negative Input for Phase A Voltage
These pins are differential inputs for phase A voltage.
V2P
V2N
15
16 I Analog
V2P: Positive Input for Phase B Voltage
V2N: Negative Input for Phase B Voltage
These pins are differential inputs for phase B voltage.
V3P
V3N
17
18 I Analog
V3P: Positive Input for Phase C Voltage
V3N: Negative Input for Phase C Voltage
These pins are differential inputs for phase C voltage.
OSCI 20 I OSC OSCI: External Crystal Input
OSCO: External Crystal Output
A 16.384 MHz crystal is connected between OSCI and OSCO. There are
two on-chip capacitor, therefore no need of external capacitors.
OSCO 21 O OSC
ZX0
ZX1
ZX2
22
23
24
OLVTTL
ZX2/ZX1/ZX0:Zero-Crossing Output
These pins are asserted when voltage or current crosses zero. Zero-cross-
ing mode can be configured by the ZXConfig register (07H).
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
10
CF1 25 O LVTTL CF1: (all-phase-sum total) Active Energy Pulse Output
CF2 26 O LVTTL
CF2: (all-phase-sum total) Reactive/ Apparent Energy Pulse Output
The output of this pin is determined by the CF2varh bit (b7, MMode0) and
the CF2ESV bit (b8, MMode0).
CF3 27 O LVTTL CF3: (all-phase-sum total) Active Fundamental Energy Pulse Output
CF4 28 O LVTTL CF4: (all-phase-sum total) Active Harmonic Energy Pulse Output
WarnOut 29 O LVTTL
WarnOut: Fatal Error Warning
This pin is asserted high when there is metering related parameter check-
sum error. Otherwise this pin stays low. Refer to 6.2.2 IRQ and WarnOut
Signal Generation.
IRQ0 30 O LVTTL
IRQ0: Interrupt Output 0
This pin is asserted when one or more events in the SysStatus0 register
(01H) occur. It is
deasserted when there is no bit set in the SysStatus0 register (01H).
In Detection mode, the IRQ0 is used to indicate the output of current detec-
tor. The IRQ0 state is cleared when entering or exiting Detection mode.
IRQ1 31 O LVTTL
IRQ1: Interrupt Output 1
This pin is asserted when one or more events in the SysStatus1 register
(02H) occur. It is deasserted when there is no bit set in the SysStatus1 regis-
ter (02H).
In Detection mode, the IRQ1 is used to indicate the output of current detec-
tor. The IRQ1 state is cleared when entering or exiting Detection mode.
PM0
PM1
33
34 ILVTTL
PM1/0: Power Mode Configuration
These two pins define the power mode of M90E36A. Refer to Tab le - 2.
DMA_CTRL 36 I LVTTL
DMA_CTRL: DMA Enable
DMA is started when this pin is asserted.
DMA is stopped when this pin is deasserted. Refer to 4 SPI / DMA Interface.
CS 37 B LVTTL
CS: Chip Select (Active Low)
In SPI mode, this pin must be driven from high to low for each read/ write
operation, and maintain low for the entire operation.
In DMA mode, this pin is asserted during data transmission. Refer to 4 SPI /
DMA Interface.
SCLK 38 B LVTTL
SCLK: Serial Clock
This pin is used as the clock for the SPI/DMA interface. Refer to 4 SPI /
DMA Interface.
SDO 39 B LVTTL
SDO: Serial Data Output
This pin is used as the data output for the SPI mode and input for the DMA
mode. Refer to 4 SPI / DMA Interface.
SDI 40 B LVTTL
SDI: Serial Data Input
This pin is used as the data input for the SPI mode and output for the DMA
mode. Refer to 4 SPI / DMA Interface.
TEST 32 I LVTTL This pin should be always connected to DGND in system application.
NC 35, 45, 46 NC: These pins should be left open.
Table-1 Pin Description (Continued)
Name Pin No. I/O Type Description
11
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
3 FUNCTION DESCRIPTION
3.1 POWER SUPPLY
The M90E36A works with single power rail 3.3V. An on-chip voltage regulator regulates the 1.8V voltage for the digital
logic.
The regulated 1.8V power is connected to the VDD18 pin. It needs to be bypassed by an external capacitor.
The M90E36A has multiple power modes, in Idle and Detection modes the 1.8V power regulator is not turned on and the
digital logic is not powered. When the logic is not powered, all the configured register values are not kept (all context lost)
except for Detection mode related registers (10H~13H) for Detection mode configuration.
User has to re-configure the registers in Partial Measurement mode or Normal mode when transiting from Idle or Detection
mode. Refer to 3.7 Power Mode for power mode details.
3.2 CLOCK
The M90E36A has an on-chip oscillator and can directly connect to an external crystal.
The OSCI pin can also be driven with a clock source.
The oscillator will be powered down in Idle and Detection power modes, as described in 3.7 Power Mode.
3.3 RESET
There are three reset sources for the M90E36A:
-RESET pin
-On-chip Power On Reset circuit
-Software Reset generated by the Software Reset register
3.3.1 RESET PIN
The RESET pin can be asserted to reset the M90E36A. The RESET pin has RC filter with typical time constant of 2μs in the I/
O, as well as a 2μs (typical) de-glitch filter.
Any reset pulse that is shorter than 2μs can not reset the M90E36A.
3.3.2 POWER ON RESET (POR)
The POR circuit resets the M90E36A at power up.
POR circuit triggers reset when:
-DVDD power up, crossing the power-up threshold. Refer to Figure-26.
-VDD18 regulator changing from disable to enable, i.e. from Idle or Detection mode to Partial Measurement mode or
Normal mode. Refer to Figure-25.
3.3.3 SOFTWARE RESET
Chip reset can be triggered by writing to the SoftReset register in Normal mode. The software reset is the same as the
reset scope generated from the RESET pin or POR.
These three reset sources have the same reset scope.
All digital logics and registers, except for the Harmonic Ratio registers will be subject to reset. The Harmonic Ratio registers
can not be reset.
•Interface logic: clock dividers
•Digital core/ logic: All registers except for the Harmonic Ratio registers and some other special registers, refer to
6.3.1 Detection Mode Registers.
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
12
3.4 METERING FUNCTION
The accumulated energy is converted to pulse frequency on the CF pins and stored in the corresponding energy registers.
The M90E36A provides energy accumulation registers with 0.1 or 0.01 CF resolution. 0.01CF / 0.1CF setting is defined by
the 001LSB bit (b9, MMode0).
3.4.1 THEORY OF ENERGY REGISTERS
The energy accumulation runs at 1 MHz clock rate, by accumulating the power value calculated by the DSP processor.
The power accumulation process is equivalent to digitally integrating the instantaneous power with a delta-time of about
1us. The accumulated energy is used to calculate the CF pulses and the corresponding internal energy registers.
The accumulated energy is converted to frequency of the CF pulses. One CF usually corresponds to 1KWh / MC (MC is
Meter Constant, e.g. 3200 imp/kWh), and is usually referenced as an energy unit in this datasheet. The internal energy res-
olution for accumulation and conversion is 0.01 CF.
The 0.01 CF pulse energy constant is referenced as 'PL_constant'.
Within 0.01 CF, forward and reverse energy are counteracted. When energy exceeds 0.01 pulse, the respective forward/
reverse energy is increased.
Take the example of active energy, suppose:
T0: Forward energy register is 12.34 pulses and reverse energy register is 1.23 pulses.
From t0 to t1: 0.005 forward pulses appeared.
From t1 to t2: 0.004 reverse pulses appeared.
From t2 to t3: 0.005 reverse pulses appeared.
From t3 to t4: 0.007 reverse pulses appeared.
The following table illustrates the process of energy accumulation process:
When forward/reverse energy reaches 0.1/0.01 pulse, the respective register is updated. When forward or reverse energy
reaches 1 pulse, CFx pins output pulse and the REVP/REVQ bits (b7~0, SysStatus1) are updated. Refer to Figure-3.
t0 t1 t2 t3 t4
Input energy + 0.005 -0.004 -0.005 -0.007
Bidirectional energy accumulator 0.005 0.001 -0.004 -0.001
Forward 0.01 CF 0000
Reverse 0.01CF 0001
Forward energy register 12.34 12.34 12.34 12.34 12.34
Reverse energy register 1.23 1.23 1.23 1.23 1.24
13
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
Figure-3 Energy Register Operation Diagram
For all-phase-sum total of active, reactive and (arithmetic sum) apparent energy, the associated power is obtained by sum-
ming the power of the three phases. The accumulation method of all-phase-sum energy is determined by the EnPC/EnPB/
EnPA/ABSEnP/ABSEnQ bits (b0~b4, MMode0).
Note that the direction of all-phase-sum power and single-phase power might be different.
CF Gen
Logic CF pulse
Bi-directional Energy
accumulator, roll over
positive/negative @
0.01CF
Forward
energy register
accumulator
reverse energy
register
accumulator
Energy accumulator
@ 1Mhz
(-)0.01
CF
(+)0.01
CF
+
ENA
ABS or Arithmetic
ENB ENC
Phase-A
Phase-B
Phase-C
Power
All-phase
sum
Positive CF
Accumulator
Negative 0-CF
Accumulator
CF[P/Q]RevFlag
Forward
energy
accumulator
Backward
energy
accumulator
Energy
accumulator @
1Mhz
(-)0.01
CF
(+)0.01
CF
Bi-directional
Energy
accumulator,
roll over
positive/nega
tive @
0.01CF
Forward
energy
accumulator
Backward
energy
accumulator
Energy
accumulator @
1Mhz
(-)0.01
CF
(+)0.01
CF
Bi-directional Energy
accumulator, roll over
positive/negative @
0.01CF
Forward energy
register
accumulator
Reverse energy
register
accumulator
Energy accumulator @
1Mhz
(-)0.01
CF
(+)0.01
CF Rev[P/Q]chg[A/BC}
Rev[P/Q]chgT
A/B/C
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
14
3.4.2 ENERGY REGISTERS
The M90E36A meters non-decomposed total active, reactive and apparent energy, as well as decomposed active funda-
mental and harmonic energy. The registers are listed as below.
3.4.2.1 Total Energy Registers
Each phase and all-phase-sum has the following registers:
- Active forward/ reverse
- Reactive forward/ reverse
- Apparent energy
In addition, there is an apparent energy all-phase vector sum register.
Altogether there are 21 energy registers. Those registers are defined in 6.5.1 Regular Energy Registers.
3.4.2.2 Fundamental and Harmonic Energy Registers
The M90E36A counts decomposed active fundamental and harmonic energy. Reactive energy is not decomposed to fun-
damental and harmonic.
The fundamental/harmonic energy is accumulated in the same way as active energy accumulation method described
above.
Registers:
- Fundamental / harmonic
- all-phase-sum / phase A / phase B / phase C
- Forward / reverse
Altogether there are 16 energy registers. Refer to 3.4.2.2 Fundamental and Harmonic Energy Registers.
3.4.3 ENERGY PULSE OUTPUT
CF1 is fixed to be total active energy output (all-phase-sum). Both forward and reverse energy registers can generate the
CF pulse (change of forward/ reverse direction can generate an interrupt if enabled).
CF2 is reactive energy output (all-phase-sum) by default. It can also be configured to be arithmetic sum apparent energy
output (all-phase-sum) or vector sum apparent energy output (all-phase-sum).
CF3 is fixed to be active fundamental energy output (all-phase-sum).
CF4 is fixed to be active harmonic energy output (all-phase-sum).
Figure-4 CFx Pulse Output Regulation
For CFx pulse width regulation, refer to Figure-4.
Case1 T>=160ms, Tp=80ms
Case 2 10ms<=T<160ms, Tp=T/2
Case 3 If Calculated T < 10ms, force T=10ms, Tp=5ms
CFx
Tp=80ms
Tp=0.5T
T≥160ms 10ms≤T<160ms
Tp=5ms
if T<10ms,
force T=10ms
15
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
3.4.4 STARTUP AND NO-LOAD POWER
There are startup power threshold registers (e.g. PStartTh(35H)). Refer to 6.4 Configuration and Calibration Registers. The
power threshold registers are defined for all-phase-sum active, reactive and apparent power. The M90E36A starts metering
when the corresponding all-phase-sum power is greater than the startup threshold. When the power value is lower than the
startup threshold, energy is not accumulated and it is assumed as in no-load status. Refer to Figure-5.
There are also no-load Current Threshold registers for Active, Reactive and Apparent energy metering participation for
each of the 3 phases. If |P|+|Q| is lower than the corresponding power threshold, that particular phase will not be accumu-
lated. Refer to the PStartTh register and other threshold registers.
There are also no-load status bits (the TPnoload/TQnoload bits (b14~15, EnStatus0)) defined to reflect the no-load status.
The M90E36A does not output any pulse in no-load status. The power-on state is of no-load status.
Figure-5 Metering Startup Handling
0
1
Phase Active
Power from DSP
0Phase Active
Energy Metering
Power Threshold
|P|+|Q|>
PPhaseTh?
0
1
0
0
1
Phase ReActive
Power from DSP
0Phase ReActive
Energy Metering
Power Threshold
|P|+|Q|>
QPhaseTh?
0
1
0
0
1
Phase Apparent
Power from DSP
0Phase Apparent
Energy Metering
Power Threshold
|P|+|Q|>
SPhaseTh?
0
1
0
Total Active
Energy Metering
+
ABS >
PStartTh?
0
1
0
Total Active Power
3 phases
Total ReActive
Energy Metering
+
ABS >
QStartTh?
0
1
0
Total ReActive Power
3 phases
Total (arithmetic
sum) Apparent
Energy Metering
+
ABS >
SStartTh?
0
1
0
Total Apparent Power
3 phases
A/B/C
A/B/C
A/B/C
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
16
3.5 MEASUREMENT FUNCTION
Measured parameters can be divided to 7 types as follows:
-Active/ Reactive/ Apparent Power
-Fundamental/ Harmonic Power
-RMS for Voltage and Current
-Power Factor
-Phase Angle
-Frequency
-Temperature
Measured parameters are average values that are averaged among 16 phase-voltage cycles (about 320ms at 50Hz)
except for the temperature. The measured parameter update frequency is approximately 3Hz. Refer to Table-15.
3.5.1 ACTIVE/ REACTIVE/ APPARENT POWER
Active/ Reactive/ Apparent Power measurement registers can be divided as below:
-active, reactive, apparent power
-all-phase-sum / phase A / phase B / phase C
-apparent power all-phase vector sum
Altogether there are 13 power registers. Refer to 6.6.1 Power and Power Factor Registers and the SVmeanT register
(98H).
Per-phase apparent power is defined as the product of measured Vrms and Irms of that phase.
All-phase-sum power is measured by arithmetically summing the per-phase measured power. The summing of phases can
be configured by the MMode0 register.
The ‘apparent power all-phase vector sum’ is done according to
IEEE
std 1459.
3.5.2 FUNDAMENTAL / HARMONIC ACTIVE POWER
Fundamental / harmonic active power measurement registers can be divided as below:
-fundamental and harmonic power
-all-phase-sum / phase A / phase B / phase C
Altogether there are 8 power registers. Refer to 6.6.2 Fundamental/ Harmonic Power and Voltage/ Current RMS Registers.
3.5.3 MEAN POWER FACTOR (PF)
Power Factor is defined for those cases: all-phase-sum / phase A / phase B / phase C.
Altogether there are 4 power factor registers. Refer to 6.6.1 Power and Power Factor Registers.
For all-phase:
The all-phase-sum apparent power selection is defined by the CF2ESV bit (b6, MMode0).
For each of the phase::
3.5.4 VOLTAGE / CURRENT RMS
Voltage/current RMS registers can be divided as follows:
Per-phase: Phase A / Phase B / Phase C
Voltage / Current
Altogether there are 6 RMS registers.
Neutral Line Current RMS:
owerapparent_p sumAll_phase_
eractive_pow sumAll_phase_
= PF_all
owerapparent_p
eractive_pow
= PF_phase
17
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
Neutral line current can be measured by A/D, or calculated by instantaneous value .
Altogether there are 2 N line current RMS registers.
Refer to 6.6.2 Fundamental/ Harmonic Power and Voltage/ Current RMS Registers.
3.5.5 PHASE ANGLE
Phase Angle measurement registers can be divided as below:
-phase A / phase B / phase C
-voltage / current
Altogether there are 6 phase angle registers. Refer to 6.6.3 THD+N, Frequency, Angle and Temperature Registers.
Note: Calculation of phase angle is based on zero-crossing interval and frequency. There might be big error when voltage/
current at low value.
3.5.6 FREQUENCY
Frequency is measured using phase A voltage by default. When phase A has voltage sag, phase C is used, and phase B is
used when both phase A and C have voltage sag.
Refer to 6.6.3 THD+N, Frequency, Angle and Temperature Registers.
3.5.7 TEMPERATURE
Chip Junction-Temperature is measured roughly every 100 ms by on-chip temperature sensor.
Refer to 6.6.3 THD+N, Frequency, Angle and Temperature Registers.
3.5.8 THD+N FOR VOLTAGE AND CURRENT
Voltage THD+N is defined as:
Current THD+N's definition is similar to that of voltage.
Registers:
-voltage and current
-phase A / phase B / phase C
Altogether there are 6 THD+N registers. Refer to 6.6.3 THD+N, Frequency, Angle and Temperature Registers.
The THD+N measurement is mainly used to monitor the percentage of harmonics in the system. Accuracy is not guaran-
teed when THD+N is lower than 10%.
CBAN iiii ++=
entalrms_fundam
entalrms_fundamrms_total
V
V-(V
22 )
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
18
3.6 FOURIER ANALYSIS FUNCTION
The M90E36A offers a hardware DFT Engine for 2
nd
to 32
nd
order harmonic component, both V and I of each phase with
the same time period.
The registers can be divided as follows:
-voltage and current for each phase
-phase A / phase B / phase C
-32 frequency components (fundamental value, and harmonic ratios)
-Total Harmonic Distortion (THD)
The harmonic analysis is implemented with a DFT engine. The DFT period is 0.5 second, which gives a resolution fre-
quency bin of 2Hz. The input samples are multiplied with a Hanning window before feeding to the DFT processor. The DFT
processor computes the fundamental and harmonic components based on the measured line frequency and sampling rate,
which is 8KHz.
Figure-6 Analysis Function
Hanning
Window
X
DFT
Computation
Engine
Frequency
Components
for
Fundamental
and Harmonic
Post-
Processing
Ratios for
Fundamental
and Harmonic
Harmonic Analyzer
Line Frequency Sample
Frequency
Sample
Capture
Input
sample
from DSP
processor
X
Scaler
To DMA Module
19
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
3.7 POWER MODE
The M90E36A has four power modes. The power mode is solely defined by the PM1 and PM0 pins.
3.7.1 NORMAL MODE (N MODE)
In Normal mode, all function blocks are active except for current detector block. Refer to Figure-7.
Figure-7 Block Diagram in Normal Mode
Table-2 Power Mode Mapping
PM1:PM0 Value Power Mode
11 Normal (N mode)
10 Partial Measurement (M mode)
01 Detection (D mode)
00 Idle (I mode)
VDD18 Regulator
Temperature Sensor
Current Detector
ADC-V1
ADC-V2
ADC-V3
ADC-I1
ADC-I2
ADC-I3
ADC-IN
SPI Interface
DSP
Energy Metering
(Forward/Reverse
Active/Reactive/CF Generator)
Measure and Monitoring
(V/I/rms, SAG, Phase, Freq)
Signal Analyzer
ADC sample capture, THD
Control Logic
Zero
Crossing
CF Out
Power On Reset Crystal Oscillator
DMA
Reference Voltage
OSCI OSCO
Power Mode
Configuration
Disabled
IRQ
Warn
Out
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
20
3.7.2 IDLE MODE (I MODE)
In Idle mode, all functions are shut off.
The analog blocks' power supply is powered but circuits are set into power-down mode, i.e, power supply applied but all
current paths are shut off. There is very low current since only very low device leakage could exist in this mode.
The digital I/Os' supply is powered.
In I/O and analog interface, the input signals from digital core (which is not powered) will be set to known state as described
in Ta b le-3. The PM1 and PM0 pins which are controlled by external MCU are active and can configure the M90E36A to
other modes.
Figure-8 Block Diagram in Idle Mode
Please note that since the digital I/O is not shut off, the I/O circuit is active in the Idle mode. The application shall make sure
that valid logic levels are applied to the I/O.
Table - 3 lists digital I/O and power pins’ states in Idle mode. It lists the requirements for inputs and the output level for out-
put. For bi-directional pins, the direction is defined.
VDD18 Regulator
Temperature Sensor
Current Detector
ADC-V1
ADC-V2
ADC-V3
ADC-I1
ADC-I2
ADC-I3
ADC-IN
SPI Interface
DSP
Energy Metering
(Forward/Reverse
Active/Reactive/CF Generator)
Measure and Monitoring
(V/I/rms,SAG, Phase, Freq)
Signal Analyzer
ADC Sample Capture, THD
Control Logic
Zero
Crossing
CF Out
Power On Reset Crystal Oscillator
DMA
Reference Voltage
OSCI OSCO
Power Mode
Configuration
Disabled
IRQ
Warn
Out
21
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
Table-3 Digital I/O and Power Pin States in Idle Mode
Name I/O type Type Pin State in Idle Mode
Reset I LVTTL Input level shall be VDD33.
CS BLVTTL
I/O set in input mode.
Input level shall be VDD33 or VSS.
SCLK B LVTTL I/O set in input mode.
Input level shall be VDD33 or VSS.
SDO B LVTTL I/O set in input mode.
Input level shall be VDD33 or VSS.
SDI B LVTTL I/O set in input mode.
Input level shall be VDD33 or VSS.
PM1
PM0 ILVTTL
As defined in Ta bl e -2
OSCI
OSCO
I
OOSC Oscillator powered down.
OSCO stays at fixed (low) level.
ZX0
ZX1
ZX2
OLVTTL0
CF1
CF2
CF3
CF4
OLVTTL0
WarnOut O LVTTL 0
IRQ0
IRQ1 OLVTTL0
DMA_CTRL I LVTTL I/O set in input mode.
Input level shall be VDD33 or VSS.
VDD18 I Power Regulated 1.8V: high impedance
DVDD I Power Digital Power Supply: powered by system
AVDD I Power Analog Power Supply: powered by system
Test I Input Always tie to ground in system application
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
22
3.7.3 DETECTION MODE (D MODE)
In Detection mode, the current detector is active. The current detector compares whether any phase current exceeds the
configured threshold using low-power comparators.
When the current of one phase or multiple phases exceeds the configured threshold, the M90E36A asserts the IRQ0 pin to
high and hold it until power mode change. The IRQ0 state is cleared when entering or exiting Detection mode.
When the current of all three current channels exceed the configured threshold, the M90E36A asserts the IRQ1 pin to high
and hold it until power mode change. The IRQ1 state is cleared when entering or exiting Detection mode.
The threshold registers need to be programmed in Normal mode before entering Detection mode.
The digital I/O state is the same as that in Idle state (except for IRQ0/IRQ1 and PM1/PM0).
The M90E36A has two comparators for detecting each phase’s positive and negative current. Each comparator’s thresh-
old can be set individually. The two comparators are both active by default, which called ‘double-side detection’. User also
can enable one comparator only to save power consumption, which called ‘single-side detection’.
Double-side detection has faster response and can detect ‘half-wave’ current. But it consumes nearly twice as much power
as single-side detection.
Comparators can be power-down by configuring the DetectCtrl register.
Figure-9 Block Diagram in Detection Mode
VDD18 Regulator
Temperature Sensor
Current Detector
ADC-V1
ADC-V2
ADC-V3
ADC-I1
ADC-I2
ADC-I3
ADC-IN
SPI Interface
DSP
Energy Metering
(Forward/Reverse
Active/Reactive/CF generator)
Measure and Monitoring
(V/I/rms, SAG, Phase, Freq)
Signal Analyzer
ADC Sample Capture, THD
Control Logic
Zero
Crossing
CF Out
Power On Reset Crystal Oscillator
DMA
Reference Voltage
OSCI OSCO
Power Mode
Configuration
Disabled
IRQ
Warn
Out
23
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
3.7.4 PARTIAL MEASUREMENT MODE (M MODE)
In this mode, Voltage ADCs, Neutral Line ADC and digital circuits are inactive.
The M90E36A measures the current RMS of one line cycle.
When the measurement is done, the M90E36A asserts the IRQ0 pin high until the Partial Measurement mode exits.
In this mode, the user needs to program the related registers (including PGA gain, channel gain, offset, etc.) to make the
current RMS measurement accurate. Refer to 5.2 Partial Measurement mode Calibration. Please note that not all registers
in this mode is accessible. Only the Partial Measurement related registers (14H~1DH) and some special registers (00H,
01H, 03H, 07H,0EH, 0FH) can be accessed.
Figure-10 Block Diagram in Partial Measurement Mode
VDD18 Regulator
Temperature Sensor
Current Detector
ADC-V1
ADC-V2
ADC-V3
ADC-I1
ADC-I2
ADC-I3
ADC-IN
SPI Interface
DSP
Energy Metering
(Forward/Reverse
Active/Reactive/CF
generator)
Measure and Monitoring
(V/I/rms, SAG, Phase, Freq)
Signal analyzer
ADC sample capture, THD
Control Logic
Zero
Crossing
CF Out
Power On Reset Crystal Oscillator
DMA
Reference Voltage
OSCI OSCO
Power Mode
Configuration
Disabled
IRQ
Warn
Out
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
24
3.7.5 TRANSITION OF POWER MODES
The above power modes are controlled by the PM0 and PM1 pins. In application, the PM0 and PM1 pins are connected to
external MCU. The PM0 and PM1 pins have internal RC- filters.
Generally, the M90E36A stays in Idle mode most of the time while outage. It enters Detection mode at a certain interval (for
example 5s) as controlled by the MCU. It informs the MCU if the current exceeds the configured threshold. The MCU then
commands the M90E36A to enter Partial Measurement mode at a certain interval (e.g. 60s) to read related current. After
current reading, the M90E36A gets back to the Idle mode.
The measured current may be used to count energy according to some metering model (like current RMS multiplying the
rated voltage to compute the power).
Any power mode transition goes through the Idle mode, as shown in Figure-11.
Figure-11 Power Mode Transition
Normal Mode
Idle Mode
Detection Mode Partial
Measurement Mode
25
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
3.8 EVENT DETECTION
3.8.1 ZERO-CROSSING DETECTION
Zero-crossing detector detects the zero-crossing point of the fundamental component of voltage and current for each of the
3 phases.
Zero-crossing signal can be independently configured and output. Refer to the definition of the ZXConfig register.
3.8.2 SAG DETECTION
Usually in the application the Sag threshold is set to be 78% of the reference voltage. The M90E36A generates Sag event
when there are less than three 8KHz samples (absolute value) greater than the sag threshold during two continuous 11ms
time-window.
For the computation of Sag threshold register value, refer to application note 46104.
The Sag event is captured by the SagWarn bit (b3, SysStatus0). If the corresponding IRQ enable bit the SagWnEn bit (b3,
FuncEn0) is set, IRQ can be generated. Refer to Figure-28.
3.8.3 PHASE LOSS DETECTION
The phase loss detection detects if there is one or more phases’ voltage is less than the phase-loss threshold voltage.
The processing and handling is similar to sag detection, only the threshold is different. The threshold computation flow is
also similar. The typical threshold setting could be 10% Un or less.
If any phase line is detected as in phase-loss mode, that phase’s zero-crossing detection function (both voltage and cur-
rent) is disabled.
3.8.4 NEUTRAL LINE OVERCURRENT DETECTION
3.8.4.1 Sampled N-Line
The neutral line measured RMS is checked with the threshold defined in the INWarnTh1 register. If the N Line current is
greater than the threshold, the INOv1 bit (b15, SysStatus1) is set. IRQ1 is generated if the corresponding Enable bit (the
INOv1En bit (b15, FuncEn1)) is set.
3.8.4.2 Computed N-Line
The neutral line computed current (calculated) RMS is checked with the threshold defined in the INWarnTh0 register. If the
N Line current is greater than the threshold, the INOv0 bit (b14, SysStatus1) bit is set. IRQ1 is generated if the correspond-
ing Enable bit the INOv0En bit (b14, FuncEn1) is set.
3.8.5 PHASE SEQUENCE ERROR DETECTION
The phase sequence is detected in two cases: 3P4W and 3P3W, which is defined by the 3P3W bit (b8, MMode0).
3P4W case:
Correct sequence: Voltage/current zero-crossing sequence: phase-A, phase-B and phase-C.
3P3W case:
Correct sequence: Voltage/current zero-crossing between phase-A and phase-C is greater than 180 degree.
If the above mentioned criteria are violated, it is assumed as a phase sequence error.
3.9 DC AND CURRENT RMS ESTIMATION
The M90E36A has a module named ‘PMS’ which can estimate current channel RMS or current channel arithmetic average
(DC component). The measurement type is defined in the PMConfig register. It can be used to estimate current RMS in
Partial Measurement mode. Since the PMS block only consume very small power, it can be also used to estimate current
RMS in Normal mode. The PMS module is turned on in both Partial Measurement mode and Normal mode.
The result is in different format and different scale for the RMS and average respectively. The RMS result is unsigned; while
current average is signed.
Refer to 6.3.2 Partial Measurement mode Registers for associated register definition.
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
26
4 SPI / DMA INTERFACE
4.1 INTERFACE DESCRIPTION
The interface can work in two modes: Slave (SPI) mode and Master mode, which is also named DMA (Direct Memory
Access) mode. The interface mode is determined by the DMA_CTRL pin as below:
Five pins are associated with the interface as below:
• SDI – Data pin, bi-directional.
• SDO – Data pin, bi-directional.
• SCLK – Bi-directional pin. It is a clock output pin in master mode and clock input pin in slave mode.
•CS – Bi-directional chip select pin . It is an output pin in master mode and input pin in slave mode.
• DMA_CTRL – Uni-directional input pin. The external device pull this pin high to control the interface work in master
mode for data dumping in DMA mode.
Figure-12 Slave Mode
Figure-13 Master Mode (PIN_DIR_SEL=0)
Mode DMA_CTRL Description
Slave (SPI) Mode 0 The interface works as normal four-wire
SPI interface.
Master (DMA) Mode 1 The interface operates as a master and
dumps data to the other devices.
SPI Interface logic
(As slave)
MISO
MOSI
SCK
CS
Host controller in
master mode
SCK
GPIO1
MOSI
MISO
SCLK
CS
GPIO2
DMA_CTRL DMA_CTRL=0
SDI
SDO
SPI Interface logic
(As master)
MOSI
MISO
SCK
CS
DSP slave mode
SCK
SPISS
MOSI
MISO
SDI
SDO
SCLK
CS
DMA_CTRL=1
DMA_CTRL GPIO
27
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
4.2 SLAVE MODE: SPI INTERFACE
The interface works in slave mode when the DMA_CTRL pin is low as shown in Figure-12.
4.2.1 SPI SLAVE INTERFACE FORMAT
In the SPI mode, data on SDI is shifted into the chip on the rising edge of SCLK while data on SDO is shifted out of the chip
on the falling edge of SCLK.
Refer to Figure-14 and Figure-15 below for the timing diagram.
Access type:
The first bit on SDI defines the access type as below:
Address:
Fixed 15-bit, following the access type bits. The lower 10-bit is decoded as address; the higher 5 bits are ‘Don't Care’.
Read/Write data:
Fixed as 16 bits.
Read Sequence:
Figure-14 Read Sequence
Write Sequence:
Figure-15 Write Sequence
Instruction Description Instruction Format
Read read from registers 1
Write write to registers 0
CS
SCLK
SDI
SDO
101 2 3 4 5 6 7 8 9 111213141516171819202122 24
A3A6 A5 A4
Register Address
High Impedance D15
Don't care
D0
16-bit data
23
D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1
25 26
A2 A1 A0
27 28 29 30 31 32
A8
XXXXX A7
A9
CS
SCLK
SDI
SDO
10123456789 11121314151617181920212223
A3A7 A6 A5 A4
16-bit data
High Impedance
D0D7 D6 D5 D4 D3 D2 D1
Register Address
D15
24
D14 D13 D12 D11 D10 D9 D8
A0A1A2
25 26 27 28 29 30 31 32
A8
XXXXX A9
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
28
4.2.2 RELIABILITY ENHANCEMENT FEATURE
The SPI read/write transaction is CS-low defined. Each transaction can only access one register.
Within each CS-low defined transaction:
Write: access occurs only when CS goes from low to high and there are exactly 32 SCLK cycles received during CS low
period.
Read: if SCLK>=16 (full address received), data is read out from internal registers and gets to the SDO pin; and the LastS-
PIData register is updated. The R/C registers can only be cleared after the LastSPIData register is updated.
4.3 MASTER MODE: DMA
The interface is defined to connect with various DSP processors for ADC samples dumping.
For DMA configure please refer to DMACtrl register definition in 6.2 Special Registers.
The interface works in Master mode when the DMA_CTRL pin is pulled high by the external device. In Master mode, regis-
ters in M90E36A cannot be accessed. The dump transaction can be stopped by the external device via pulling the
DMA_CTRL pin to low at any time.
Figure-13 shows a connection between M90E36A and a DSP processor where M90E36A acts as the master.
4.3.1 DMA BURST TRANSFER FOR ADC SAMPLING
When the DMA_CTRL pin changes from low to high, the voltage and current channel ADC samples (after decimation and
frequency compensation) are dumped out serially through the interface with SCLK frequency defined by the CLK_DIV[3:0]
bits (b3~0, DMACtrl).
When the M90E36A detects that the DMA_CTRL pin is de-asserted, it stops the DMA transaction after the current sample
has been sent.
Clock Dividing Ratio
The SCLK frequency of SPI interface is defined by the CLK_DIV[3:0] bits (b3~0, DMACtrl) as the following equation:
Here fsys_clk means system’s oscillator frequency.
Interface Direction
In DMA mode, the interface direction of SDI/SDO pins are normally defined as Figure-13. But the direction also can be
swapped by configuring the PIN_DIR_SEL bit (b8, DMACtrl).
ADC Channel Selection
Internally, the M90E36A has 7 ADC channels. The user can select which channel’s samples to be dumped out via configur-
ing the ADC_CH_SEL[15:9] bits (b15~9, DMACtrl).
Each bit of the 7-bit field ADC_CH_SEL enables the data dumping for one ADC channel. Set ‘1’ to a bit enables the dump
of the corresponding ADC channel samples.
Clock Modes
Four clock modes are defined in master mode according to the CLK_DRV bit (b4, DMACtrl) and CLK_IDLE bit (b5, DMAC-
trl) configuration as the following diagram shows.
2+2*CLK_DIV
f
= f sys_clk
SCLK
29
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
Figure-16 Clock Mode0 (CLK_DRV=0, CLK_IDLE=0) and Mode1 (CLK_DRV=0, CLK_IDLE=1)
Figure-17 Clock Mode2 (CLK_DRV=1, CLK_IDLE=0) and Mode3 (CLK_DRV=1, CLK_IDLE=1)
For mode0 and mode1 (CLK_DRV = 0), the first edge of SCLK is used by the slave to sample the data.
For mode2 and mode3 (CLK_DRV=1), the first edge of SCLK is used by the master to drive out the data.
CS
Deactivation for Rate Adaptation
Since the bit rate may be higher than the equivalent bit rate of the samples (For example, for 24-bit non-frame mode, the
equivalent bit-rate is sample_rate*6*24bps). To compensate for that, the CS signal is de-asserted to wait for the new sam-
ples and be asserted again once the new sample arrives.
There are at least 2 SCLK clock periods for CS resume from de-asserted state to assert state depending on the Clock Divid-
ing Ratio and ADC Channel Selection. During CS de-asserted state, the SCLK stays in idle state as configured by the
CLK_IDLE bit (b5, DMACtrl).
Data Frame Format and Sample Sequence in DMA Mode
The M90E36A sends the ADC samples (In 8K sample rate) continuously in DMA mode.
The samples of all enabled ADC channels are sent out in interleaved manner, with the sequence of I4, I1, V1, I2, V2, and
I3, V3 (If any channel is disabled, remove it from the list while maintaining the sequence of the other channels). Figure-18
shows an example of the sample sequence when the ADC_CH_SEL[15:9] bits (b15~9, DMACtrl) are configured to be
‘0101001’.
CLOCK Cycle #
SCLK
(CLK_IDLE=0)
SCLK
(CLK_IDLE=1)
SDI/SDO
CS
1234 N-2 NN-1
CLOCK Cycle #
SCLK
(CLK_IDLE=0)
SCLK
(CLK_IDLE=1)
SDI/SDO
CS
1234 N-2 NN-1
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
30
Figure-18 Sample Sequence Example
Bit Sequence
The samples sent over the interfaces are the processed data according to the CH_BITWIDTH[7:6] bits (b7~6, DMACtrl). All
the samples sent are MSB first. Figure-19 shows an example of sample bit sequence for 32-bit sample bit width.
Figure-19 Sample Bit Sequence Example
4.3.2 CONTROL SEQUENCE FOR EXTERNAL DEVICE
To start and stop the DMA dump sequence, the external device follows the rules described below:
• Start of the dump process:
a) The external device configures the DMACtrl register.
b) The external device switches to SPI slave mode. Note that the parameters of clock idle state / driving edge, sample bit
width and pin direction of SPI_D0/SPI_D1 configured to M90E36A should match with external device's settings.
c) The external device asserts the DMA_CTRL signal. The M90E36A swaps I/O direction if necessary after it has
detected that master has asserted the DMA. The samples are dumped out with a delay of at most 1 sample period (125us).
• Stop of the dump process:
a) The external device de-asserts the DMA_CTRL signal. The M90E36A stops the transaction after current (all selected)
samples have been successfully sent out.
b) The external device waits one sample period of 125us or detects that the CS signal is pulled high, then switches the
interface back to master mode.
Samples on
MOSI
CS
I1 I2 V3 I1 I2 V3 I1 I2 V3
Samples 1
T=125µs
Samples 2 Samples N
Samples
Samples on MOSI
CS
I1 I2 V3
b23 b16 b15 b8b7b00000
I1 sample N
8 pads
0000
31
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
5 CALIBRATION METHOD
5.1 NORMAL MODE OPERATION CALIBRATION
Calibration is done per phase and there is no need to calibrate for the all-phase-sum (total) parameters. The calibration
method is as follows:
Step-1: Register configuration for calibration
-Start to configure the System configuration Registers by writing 5678H to the ConfigStart register.
-The M90E36A automatically reset the configuration registers to their default value.
-Program all the system configuration registers.
-Calculate and write the checksum to the CS0 register.
-Write 8765H to the ConfigStart register (enable checksum checking).
-System may check the WarnOut pin to see if there is a checksum error.
The start register and checksum handling scheme is the same throughout the calibration process, so the following section
does not describe the start and checksum operation.
Step-2: Measurement calibration (per-phase)
-First calibrate offset at I = 0, U = 0 for current or/and voltage;
•Configure calculated channel Gain (The user needs to program the PGA gain and DPGA gain properly in order to
get the calculated gain within 0 to 2 in step-1).
•Read Irms/ Urms value.
•Calculate the compensation value.
•Write the calculated value to the offset register.
-Then calibrate gain at I = In (Ib), U = Un for current and voltage;
•Read Irms/ Urms value.
•Calculate the compensation value.
•Write the calculated value to the Gain register.
Step-3: Metering calibration (per phase)
-First calibrate the Power/ Energy offset.
•U = Un, I = 0.
•Read full 32 bits (or lower 16 bits) Active and Reactive Power
•Calculate the compensation values
•Write the calculated values to the offset registers respectively.
-Then calibrate Energy gain at unity power factor:
•PF=1.0, U = Un, I = In (Ib).
•Connect CF1 to the calibration bench;
•User/ PC calculate the energy gain according to the data got from calibration bench
•Write the calculated value to the Energy Gain register.
-Then calibrate the phase angle compensation at 0.5 inductive power factor.
•PF=0.5L, U = Un, I = In (Ib), Rated frequency = 50Hz, or 60Hz according to the application;
•CF1 connected to the calibration bench;
•User/ PC calculate the phase angle according to the data got from calibration bench;
•Write the calculated value to the Phase angle register.
5.2 PARTIAL MEASUREMENT MODE CALIBRATION
The calibration method is as follows:
Step-1: Set the input current to zero and measure the current mean value (set MeasureType = 1, write 1 to the ReMeasure
bit (b14, PMConfig) to trigger the measurement. Refer to the PMIrmsA register). Negate the result register (the PMIrmsA/
PMIrmsB/PMIrmsC registers) reading (16-bit) and then write the result to the offset register.
Step-2: The output of Partial Measurement result = ADC_input_voltage *PGA_gain*DPGA_gain*65536 / 1.2. For instance,
a 150 mVrms signal (from CT) with PGA = 1 gets 8192 in the RMS result register.
Step-3: The user needs to do its own conversion to get meaningful result. The scaling factor in user's software could be
calibrated device per device.
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
32
6REGISTER
6.1 REGISTER LIST
Table-4 Register List
Register
Address Register Name
Read/
Write
Type Functional Description Comment Page
Status and Special Register
00H SoftReset W Software Reset P40
01H SysStatus0 R/C System Status 0 P41
02H SysStatus1 R/C System Status 1 P41
03H FuncEn0 R/W Function Enable 0 P43
04H FuncEn1 R/W Function Enable 1 P43
07H ZXConfig R/W Zero-Crossing Configuration Configuration of ZX0/1/2 pins’ source P45
08H SagTh R/W Voltage Sag Threshold P45
09H PhaseLossTh R/W Voltage Phase Losing Threshold Similar to Voltage Sag Threshold reg-
ister P45
0AH INWarnTh0 R/W Threshold for calculated (Ia + Ib +Ic) N
line rms current Check SysStatus0/1 register. P46
0BH INWarnTh1 R/W Threshold for sampled (from ADC) N
line rms current Check SysStatus0/1 register. P46
0CH THDNUTh R/W Voltage THD Warning Threshold Check SysStatus0/1 register. P46
0DH THDNITh R/W Current THD Warning Threshold Check SysStatus0/1 register. P46
0EH DMACtrl R/W DMA Mode Interface Control DMA mode interface control P47
0FH LastSPIData R Last Read/ Write SPI Value Refer to 4.2.2 Reliability Enhance-
ment Feature P48
Low Power Mode Register
10H DetectCtrl R/W Current Detect Control P49
11H DetectTh1 R/W Channel 1 current threshold in
Detection mode P50
12H DetectTh2 R/W Channel 2 current threshold in
Detection mode P50
13H DetectTh3 R/W Channel 3 current threshold in
Detection mode P51
14H PMOffsetA R/W Ioffset for phase A in Partial Measure-
ment mode P52
15H PMOffsetB R/W Ioffset for phase B in Partial Measure-
ment mode P52
16H PMOffsetC R/W Ioffset for phase C in Partial Measure-
ment mode P52
17H PMPGA R/W PGAgain Configuration in Partial Mea-
surement mode P52
18H PMIrmsA RIrms for phase A in Partial Measure-
ment mode P52
19H PMIrmsB RIrms for phase B in Partial Measure-
ment mode P53
1AH PMIrmsC RIrms for phase C in Partial Measure-
ment mode P53
33
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
1BH PMConfig R/W Measure configuration in Partial Mea-
surement mode P53
1CH PMAvgSamples R/W Number of 8K samples to be averaged
in RMS/mean computation P53
1DH PMIrmsLSB R LSB bits of PMRrms[A/B/C] It returns MSB of the mean measure-
ment data in Mean value test P54
Configuration Registers
30H ConfigStart R/W Calibration Start Command P56
31H PLconstH R/W High Word of PL_Constant P57
32H PLconstL R/W Low Word of PL_Constant P57
33H MMode0 R/W Metering method configuration P58
34H MMode1 R/W PGA gain configuration P59
35H PStartTh R/W Active Startup Power Threshold.
Refer to Tab l e- 5.
36H QStartTh R/W Reactive Startup Power Threshold.
37H SStartTh R/W Apparent Startup Power Threshold.
38H PPhaseTh R/W Startup Power Threshold (Active E
nergy Accumulation)
39H QPhaseTh R/W Startup Power Threshold (ReActive E
nergy Accumulation)
3AH SPhaseTh R/W Startup Power Threshold (Apparent E
nergy Accumulation)
3BH CS0 R/W Checksum 0 P60
Calibration Registers
40H CalStart R/W Calibration Start Command
Refer to Tab l e- 6.
41H PoffsetA R/W Phase A Active Power Offset P61
42H QoffsetA R/W Phase A Reactive Power Offset P61
43H POffsetB R/W Phase B Active Power Offset
44H QOffsetB R/W Phase B Reactive Power Offset
45H POffsetC R/W Phase C Active Power Offset
46H QOffsetC R/W Phase C Reactive Power Offset
47H GainA R/W Phase A calibration gain P62
48H PhiA R/W Phase A calibration phase angle P62
49H GainB R/W Phase B calibration gain
4AH PhiB R/W Phase B calibration phase angle
4BH GainC R/W Phase C calibration gain
4CH PhiC R/W Phase C calibration phase angle
4DH CS1 R/W Checksum 1
Table-4 Register List (Continued)
Register
Address Register Name
Read/
Write
Type Functional Description Comment Page
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
34
Fundamental/ Harmonic Energy Calibration registers
50H HarmStart R/W Harmonic Calibration Startup Com-
mand
Refer to Tab l e- 7.
51H POffsetAF R/W Phase A Fundamental Active Power
Offset
52H POffsetBF R/W Phase B Fundamental Active Power
Offset
53H POffsetCF R/W Phase C Fundamental Active Power
Offset
54H PGainAF R/W Phase A Fundamental Active Power
Gain
55H PGainBF R/W Phase B Fundamental Active Power
Gain
56H PGainCF R/W Phase C Fundamental Active Power
Gain
57H CS2 R/W Checksum 2
Measurement Calibration
60H AdjStart R/W Measurement Calibration Startup
Command
Refer to Tab l e- 8.
61H UgainA R/W Phase A Voltage RMS Gain
62H IgainA R/W Phase A Current RMS Gain
63H UoffsetA R/W Phase A Voltage RMS Offset
64H IoffsetA R/W Phase A Current RMS Offset
65H UgainB R/W Phase B Voltage RMS Gain
66H IgainB R/W Phase B Current RMS Gain
67H UoffsetB R/W Phase B Voltage RMS Offset
68H IoffsetB R/W Phase B Current RMS Offset
69H UgainC R/W Phase C Voltage RMS Gain
6AH IgainC R/W Phase C Current RMS Gain
6BH UoffsetC R/W Phase C Voltage RMS Offset
6CH IoffsetC R/W Phase C Current RMS Offset
6DH IgainN R/W Sampled N line Current RMS Gain
6EH IoffsetN R/W Sampled N line Current RMS Offset
6FH CS3 R/W Checksum 3
Table-4 Register List (Continued)
Register
Address Register Name
Read/
Write
Type Functional Description Comment Page
35
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
Energy Register
80H APenergyT R/C Total Forward Active Energy
Refer to Tab l e- 9.
81H APenergyA R/C Phase A Forward Active Energy
82H APenergyB R/C Phase B Forward Active Energy
83H APenergyC R/C Phase C Forward Active Energy
84H ANenergyT R/C Total Reverse Active Energy
85H ANenergyA R/C Phase A Reverse Active Energy
86H ANenergyB R/C Phase B Reverse Active Energy
87H ANenergyC R/C Phase C Reverse Active Energy
88H RPenergyT R/C Total Forward Reactive Energy
89H RPenergyA R/C Phase A Forward Reactive Energy
8AH RPenergyB R/C Phase B Forward Reactive Energy
8BH RPenergyC R/C Phase C Forward Reactive Energy
8CH RNenergyT R/C Total Reverse Reactive Energy
8DH RNenergyA R/C Phase A Reverse Reactive Energy
8EH RNenergyB R/C Phase B Reverse Reactive Energy
8FH RNenergyC R/C Phase C Reverse Reactive Energy
90H SAenergyT R/C Total (Arithmetic Sum) Apparent E
nergy
91H SenergyA R/C Phase A Apparent Energy
92H SenergyB R/C Phase B Apparent Energy
93H SenergyC R/C Phase C Apparent Energy
94H SVenergyT R/C (Vector Sum) Total Apparent Energy
95H EnStatus0 R Metering Status 0 P66
96H EnStatus1 R Metering Status 1 P66
98H SVmeanT R (Vector Sum) Total Apparent Power
99H SVmeanTLSB R LSB of (Vector Sum) Total Apparent
Power
Table-4 Register List (Continued)
Register
Address Register Name
Read/
Write
Type Functional Description Comment Page
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
36
Fundamental / Harmonic Energy Register
A0H APenergyTF R/C Total Forward Active Fundamental E
nergy
Refer to Table-10.
P67
A1H APenergyAF R/C Phase A Forward Active Fundamental
Energy
A2H APenergyBF R/C Phase B Forward Active Fundamental
Energy
A3H APenergyCF R/C Phase C Forward Active Fundamental
Energy
A4H ANenergyTF R/C Total Reverse Active Fundamental E
nergy
A5H ANenergyAF R/C Phase A Reverse Active Fundamental
Energy
A6H ANenergyBF R/C Phase B Reverse Active Fundamental
Energy
A7H ANenergyCF R/C Phase C Reverse Active Fundamental
Energy
A8H APenergyTH R/C Total Forward Active Harmonic Energy
A9H APenergyAH R/C Phase A Forward Active Harmonic E
nergy
AAH APenergyBH R/C Phase B Forward Active Harmonic E
nergy
ABH APenergyCH R/C Phase C Forward Active Harmonic E
nergy
ACH ANenergyTH R/C Total Reverse Active Harmonic Energy
ADH ANenergyAH R/C Phase A Reverse Active Harmonic E
nergy
AEH ANenergyBH R/C Phase B Reverse Active Harmonic E
nergy
AFH ANenergyCH R/C Phase C Reverse Active Harmonic E
nergy
Table-4 Register List (Continued)
Register
Address Register Name
Read/
Write
Type Functional Description Comment Page
37
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
Power and Power Factor Registers
B0H PmeanT R Total (all-phase-sum) Active Power
Refer to Tab l e- 11 .
P68
B1H PmeanA R Phase A Active Power
B2H PmeanB R Phase B Active Power
B3H PmeanC R Phase C Active Power
B4H QmeanT R Total (all-phase-sum) Reactive Power
B5H QmeanA R Phase A Reactive Power
B6H QmeanB R Phase B Reactive Power
B7H QmeanC R Phase C Reactive Power
B8H SAmeanT R Total (Arithmetic Sum) apparent power
B9H SmeanA R phase A apparent power
BAH SmeanB R phase B apparent power
BBH SmeanC R phase C apparent power
BCH PFmeanT R Total power factor
BDH PFmeanA R phase A power factor
BEH PFmeanB R phase B power factor
BFH PFmeanC R phase C power factor
C0H PmeanTLSB R Lower word of Total (all-phase-sum)
Active Power
C1H PmeanALSB R Lower word of Phase A Active Power
C2H PmeanBLSB R Lower word of Phase B Active Power
C3H PmeanCLSB R Lower word of Phase C Active Power
C4H QmeanTLSB R Lower word of Total (all-phase-sum)
Reactive Power
C5H QmeanALSB R Lower word of Phase A Reactive
Power
C6H QmeanBLSB R Lower word of Phase B Reactive
Power
C7H QmeanCLSB R Lower word of Phase C Reactive
Power
C8H SAmeanTLSB R Lower word of Total (Arithmetic Sum)
apparent power
C9H SmeanALSB R Lower word of phase A apparent
power
CAH SmeanBLSB R Lower word of phase B apparent
power
CBH SmeanCLSB R Lower word of phase C apparent
power
Table-4 Register List (Continued)
Register
Address Register Name
Read/
Write
Type Functional Description Comment Page
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
38
Fundamental / Harmonic Power and Voltage / Current RMS Registers
D0H PmeanTF R Total active fundamental power
Refer to Table-12.
P69
D1H PmeanAF R phase A active fundamental power
D2H PmeanBF R phase B active fundamental power
D3H PmeanCF R phase C active fundamental power
D4H PmeanTH R Total active harmonic power
D5H PmeanAH R phase A active harmonic power
D6H PmeanBH R phase B active harmonic power
D7H PmeanCH R phase C active harmonic power
D8H IrmsN1 R N Line Sampled current RMS
D9H UrmsA R phase A voltage RMS
DAH UrmsB R phase B voltage RMS
DBH UrmsC R phase C voltage RMS
DCH IrmsN0 R N Line calculated current RMS
DDH IrmsA R phase A current RMS
DEH IrmsB R phase B current RMS
DFH IrmsC R phase C current RMS
E0H PmeanTFLSB R Lower word of Total active fundamen-
tal Power
E1H PmeanAFLSB R Lower word of phase A active funda-
mental Power
E2H PmeanBFLSB R Lower word of phase B active funda-
mental Power
E3H PmeanCFLSB R Lower word of phase C active funda-
mental Power
E4H PmeanTHLSB R Lower word of Total active harmonic
Power
E5H PmeanAHLSB R Lower word of phase A active har-
monic Power
E6H PmeanBHLSB R Lower word of phase B active har-
monic Power
E7H PmeanCHLSB R Lower word of phase C active har-
monic Power
E9H UrmsALSB R Lower word of phase A voltage RMS
EAH UrmsBLSB R Lower word of phase B voltage RMS
EBH UrmsCLSB R Lower word of phase C voltage RMS
EDH IrmsALSB R Lower word of phase A current RMS
EEH IrmsBLSB R Lower word of phase B current RMS
EFH IrmsCLSB R Lower word of phase C current RMS
Table-4 Register List (Continued)
Register
Address Register Name
Read/
Write
Type Functional Description Comment Page
39
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
THD+N, Frequency, Angle and Temperature Registers
F1H THDNUA R phase A voltage THD+N
Refer to Table-13.
P70
F2H THDNUB R phase B voltage THD+N
F3H THDNUC R phase C voltage THD+N
F5H THDNIA R phase A current THD+N
F6H THDNIB R phase B current THD+N
F7H THDNIC R phase C current THD+N
F8H Freq R Frequency
F9H PAngleA R phase A mean phase angle
FAH PAngleB R phase B mean phase angle
FBH PAngleC R phase C mean phase angle
FCH Temp R Measured temperature
FDH UangleA R phase A voltage phase angle
FEH UangleB R phase B voltage phase angle
FFH UangleC R phase C voltage phase angle
Harmonic Fourier Analysis Registers
100H ~
1BFH R
Refer to Table-14.P71
1D0H ~
1D1H R/W
Table-4 Register List (Continued)
Register
Address Register Name
Read/
Write
Type Functional Description Comment Page
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
40
6.2 SPECIAL REGISTERS
6.2.1 SOFT RESET REGISTER
SoftReset
Software Reset
6.2.2 IRQ AND WARNOUT SIGNAL GENERATION
Status bits in the SysStatus0 register generate an interrupt and get the IRQ0 pin to be asserted if the corresponding enable
bits are set in the FuncEn0 register.
Status bits in the SysStatus1 register generate an interrupt and get the IRQ1 pin to be asserted, if the corresponding enable
bits are set in the FuncEn1 register.
Some of the status signals can also assert the WarnOut pin.
The following diagram illustrates how the status bits, enable bits and IRQ/ WarnOut pins work together.
Figure-20 IRQ and WarnOut Generation
Address: 00H
Type: Write
Default Value: 0000H
Bit Name Description
15 - 0 SoftRe-
set[15:0]
Software reset register. The M90E36A resets only if 789AH is written to this register. The reset domain is
the same as the RESET pin or Power On Reset. Reading this register always return 0.
Status 1
Status 2
Status n
Enable 2
Enable n
Register bits in
SysStatus0/1
Register bits in
FuncEn0/1
IRQ0/1
WarnOut
event capture
event capture
EN
Status without
enable
Status with enable
Read clearRead clear
Read clearRead clear
Read clearRead clear
41
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
SysStatus0
System Status 0
Address: 01H
Type: Read/Clear
Default Value: 0000H
Bit Name Description
15 - Reserved.
*
14 CS0Err
This bit indicates CS0 (3BH) checksum status.
0: CS0 checksum correct (default)
1: CS0 checksum error. The WarnOut pin is asserted at the same time.
13 - Reserved.
12 CS1Err
This bit indicates CS1 (4DH) checksum status.
0: CS1 checksum correct (default)
1: CS1 checksum error. The WarnOut pin is asserted at the same time.
11 - Reserved.
10 CS2Err
This bit indicates CS2 (57H) checksum status.
0: CS2 checksum correct (default)
1: CS2 checksum error. The WarnOut pin is asserted at the same time.
9-
Reserved.
8CS3Err
This bit indicates CS3 (6FH) checksum status.
0: CS3 checksum correct (default)
1: CS3 checksum error. The WarnOut pin is asserted at the same time.
7 URevWn
This bit indicates whether there is any error with the voltage phase sequence.
0: No error with the voltage phase sequence (default)
1: Error with the voltage phase sequence.
6 IRevWn
This bit indicates whether there is any error with the current phase sequence.
0: No error with the current phase sequence (default)
1: Error with the current phase sequence.
5 - 4 - Reserved.
3SagWarn
This bit indicates whether there is any voltage sag (voltage lower than threshold) in one phase or more.
0: No voltage sag (default)
1: Voltage sag.
2PhaseL-
oseWn
This bit indicates whether there is any voltage phase losing in one phase or more.
0: No voltage phase losing (default)
1: Voltage phase losing.
1-0 - Reserved.
Note: All reserved bits of any register should be ignored when reading and should be written with zero.
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
42
SysStatus1
System Status 1
Address: 02H
Type: Read/Clear
Default Value: 0000H
Bit Name Description
15 INOv1
This bit indicates whether the N line current sampling value is greater than the threshold set by the
INWarnTh1 register.
0: Not greater than the threshold (default)
1: Greater than the threshold.
14 INOv0
This bit indicates whether the calculated N line current is greater than the threshold set by the INWarnTh0
register.
0: Not greater than the threshold (default)
1: Greater than the threshold.
13-12 -Reserved.
11 THDUOv
This bit indicates whether one or more voltage THDUx (THDUA/ THDUB/ THDUC) is greater than the
threshold set by the THDNUTh register.
0: Not greater than the threshold (default)
1: Greater than the threshold.
10 THDIOv
This bit indicates whether one or more current THDIx (THDIA/ THDIB/ THDIC) is greater than the thresh-
old set by the THDNITh register.
0: Not greater than the threshold (default)
1: Greater than the threshold.
9DFTDone
This bit indicates whether the DFT data is ready.
0: Not ready (default)
1: Ready.
8-
Reserved.
7 RevQchgT
When there is any direction change of active/reactive energy for all-phase-sum or individual phase (from
forward to reverse, or from reverse to forward), the corresponding status bit is set. The judgment of direc-
tion change is solely based on the energy register (not related to the CF pulses), and dependent on the
energy register resolution (0.01CF / 0.1CF setting set by the 001LSB bit (b9, MMode0)).
0: direction of active/reactive energy no change (default)
1: direction of active/reactive energy changed
The status bits are RevQchgT/ RevPchgT are status bits for all-phase-sum and RevQchgA/ RevQchgB/
RevQchgC/ RevPchgA/ RevPchgB/ RevPchgC are for individual phase.
6RevQchgA
5RevQchgB
4RevQchgC
3 RevPchgT
2 RevPchgA
1 RevPchgB
0 RevPchgC
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FuncEn0
Function Enable 0
Address: 03H
Type: Read/Write
Default Value: 0000H
Bit Name Description
15-11 - Reserved.
10 CS2ErrEn
This bit determines whether to enable the interrupt when the CS2Err bit (b10, SysStatus0) is set.
0: disable (default)
1: enable
9-8 - Reserved.
7 URevWnEn
This bit determines whether to enable the interrupt when the URevWn bit (b7, SysStatus0) is set.
0: disable (default)
1: enable
6 IRevWnEn
This bit determines whether to enable the interrupt when the IRevWn bit (b6, SysStatus0) is set.
0: disable (default)
1: enable
5-4 - Reserved.
3SagWnEn
This bit determines whether to enable the voltage sag interrupt when the SagWarn bit (b3, SysStatus0) is
set.
0: disable (default)
1: enable
2PhaseL-
oseWnEn
This bit determines whether to enable the interrupt when the PhaseLoseWn bit (b2, SysStatus0) is set.
0: disable (default)
1: enable
1-0 - Reserved.
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FuncEn1
Function Enable 1
Address: 04H
Type: Read/Write
Default Value: 0000H
Bit Name Description
15 INOv1En
This bit determines whether to enable the interrupt when the INOv1 bit (b15, SysStatus1) is set.
0: disable (default)
1: enable
14 INOv0En
This bit determines whether to enable the interrupt when the INOv0 bit (b14, SysStatus1) is set.
0: disable (default)
1: enable
13-12 - Reserved.
11 THDUOvEn
This bit determines whether to enable the interrupt when the THDUOv bit (b11, SysStatus1) is set.
0: disable (default)
1: enable
10 THDIOvEn
This bit determines whether to enable the interrupt when the THDIOv bit (b10, SysStatus1) is set.
0: disable (default)
1: enable
9DFTDone
This bit determines whether to enable the interrupt when the DFTDone bit (b9, SysStatus1) is set.
0: disable (default)
1: enable
8-
Reserved.
7RevQchgTEn
These bits determine whether to enable the corresponding interrupt when any of the direction change bits
(b7~b0, SysStatus1) is set.
0: disable (default)
1: enable
6 RevQchgAEn
5 RevQchgBEn
4 RevQchgCEn
3 RevPchgTEn
2 RevPchgAEn
1 RevPchgBEn
0 RevPchgCEn
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M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
6.2.3 SPECIAL CONFIGURATION REGISTERS
ZXConfig
Zero-Crossing Configuration
SagTh
Voltage Sag Threshold
PhaseLossTh
Voltage Phase Losing Threshold
Address: 07H
Type: Read/Write
Default Value: 0001H
Bit Name Description
15:13 ZX2Src[2:0] These bits select the signal source for the ZX2, ZX1 or ZX0 pins.
12:10 ZX1Src[2:0]
9:7 ZX0Src[2:0]
6:5 ZX2Con[1:0] These bits configure zero-crossing mode for the ZX2, ZX1 and ZX0 pins.
4:3 ZX1Con[1:0]
2:1 ZX0Con[1:0]
0ZXdis
This bit determines whether to disable the ZX signals:
0: enable
1: disable all the ZX signals to ‘0’ (default).
Address: 08H
Type: Read/Write
Default Value: 0000H
Bit Name Description
15:0 SagTh Unsigned 16-bit integer with unit related to PGA and voltage sense circuits. Refer to 3.8.2 Sag Detection.
Address: 09H
Type: Read/Write
Default Value: 0000H
Bit Name Description
15:0 PhaseLossTh Unsigned 16-bit integer with unit related to PGA and voltage sense circuits. Refer to 3.8.3 Phase Loss
Detection.
Code Source
011 Fixed-0
000 Ua
001 Ub
010 Uc
111 Fixed-0
100 Ia
101 Ib
110 Ic
Code Zero-Crossing Configuration
00 positive zero-crossing
01 negative zero-crossing
10 all zero-crossing
11 no zero-crossing output
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46
INWarnTh0
Neutral Current (Calculated) Warning Threshold
INWarnTh1
Neutral Current (Sampled) Warning Threshold
THDNUTh
Voltage THD Warning Threshold
THDNITh
Current THD Warning Threshold
Address: 0AH
Type: Read/Write
Default Value: FFFFH
Bit Name Description
15:0 INWarnTh0
Neutral current (calculated) warning threshold.
Threshold for calculated (Ia + Ib +Ic) N line rms current. Unsigned 16 bit, unit 1mA.
If N line rms current is greater than the threshold, The INOv0 bit (b14, SysStatus1) will be asserted if
enabled. Refer to 3.8.4.2 Computed N-Line.
Address: 0BH
Type: Read/Write
Default Value: FFFFH
Bit Name Description
15:0 INWarnTh1
Neutral Current (Sampled) Warning threshold.
Threshold for sampled (from ADC) N line rms current. Unsigned 16 bit, unit 1mA.
If N line rms current is greater than the threshold, The INOv1 bit (b15, SysStatus1) will be asserted if
enabled. Refer to 3.8.4.1 Sampled N-Line.
Address: 0CH
Type: Read/Write
Default Value: FFFFH
Bit Name Description
15:0 THDNUTh
Voltage THD Warning threshold.
Voltage THD+N Threshold. Unsigned 16 bit, unit 0.01%.
Exceeding the threshold will assert the THDUOv bit (b11, SysStatus1) if enabled.
Address: 0DH
Type: Read/Write
Default Value: FFFFH
Bit Name Description
15:0 THDNITh
Current THD Warning threshold.
Current THD+N Threshold. Unsigned 16-bit, unit 0.01%.
Exceeding the threshold will assert the THDIOv bit (b10, SysStatus1) if enabled.
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DMACtrl
DMA Mode Interface Control
Address: 0EH
Type: Read/Write
Default Value: 7E44H
Bit Name Description
15:9 ADC_CH_SE
L
These bits configure the data source of the ADC channel. Each bit enables the data dumping for one ADC
channel as the following diagram shows. Set a ‘1’ to a bit enables the dumping of the corresponding ADC
channel samples.
Note: I1 to phase A and I3 to phase C mapping can be swapped by configuring the I1I3Swap bit (b13,
MMode0).
8PIN_DIR_SE
L
This bit configures the direction of the SDI and SDO pins.
7:6 CH_BIT_WID
TH
These bits configure the bit width for each channel.
5CLK_IDLE
This bit configures the Idle state clock level.
0: Idle low (default)
1: Idle High
4 CLK_DRV
This bit configures which edge to drive data out.
0: Second edge drives data out. (default)
1: First edge drives data out.
3:0 CLK_DIV Divide ratio to generate SCLK frequency from SYS_CLK. Default value is ‘100’.
b15 b14 b13 b12 b11 b10 b9
I4 V1I1 V2I2 V3I3
PIN_DIR_SEL Master Mode (DMA_Ctrl=1)
0SDI→MOSI
SDO←MISO
1SDI←MISO
SDO→MOSI
Code Channel Bit Width
00 32 bits
01 24 bits (default)
10 16 bits
11 reserved
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48
6.2.4 LAST SPI DATA REGISTER
LastSPIData
Last Read/Write SPI Value
Address: 0FH
Type: Read
Default Value: 0000H
Bit Name Description
15:0
LastSPIData1
5 -
LastSPIData0
This register is a special register which logs data of the previous SPI Read or Write access especially for
Read/Clear registers. This register is useful when the user wants to check the integrity of the last SPI
access.
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Atmel-46004B-SE-M90E36A-Datasheet_021215
6.3 LOW-POWER MODES REGISTERS
6.3.1 DETECTION MODE REGISTERS
Current Detection register latching scheme is:
When any of the 4 current detection registers (0x10 - 0x13) were programmed, all the 4 current detection registers (includ-
ing the registers that not being programmed) will be automatically latched into the current detector's internal configuration
latches at the same time. Those latched configuration values are not subject to digital reset signals and will be kept in all
the 4 power modes. The power up value of those latches is not deterministic, so user needs to program the current detec-
tion registers to update.
Figure-21 Current Detection Register Latching Scheme
DetectCtrl
Current Detect Control
Address: 10H
Type: Read/Write
Default Value: 0000H
Bit Name Description
15:6 - Reserved.
5:0 DetectCtrl
Detector power-down, active high:
[5:3]: Power-down for negative detector of channel 3/2/1;
[2:0]: Power-down for positive detector of channel 3/2/1.
0x10
0x11
0x12
0x13
latch
latch
latch
latch
Current detector
register Write
update
registers Current Detector block
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50
DetectTh1
Channel 1 Current Threshold in Detection Mode
DetectTh2
Channel 2 Current Threshold in Detection Mode
Address: 11H
Type: Read/Write
Default Value: 0000H
Bit Name Description
15 - Reserved.
14:8 CalCodeN
Channel 1 current negative detector calculation code.
Code mapping:
7'b000-0000, Vc=-4.28mV=-3.03mVrms (Vc is the threshold of low power computation)
7'b111-1111, Vc=12.91mV=9.14mVrms
DAC typical resolution is [12.91-(-4.28)]/127=135.4μV=95.7μVrms
7 - Reserved.
6:0 CalCodeP
Channel 1 current positive detector calculation code.
Code mapping:
7'b000-0000, Vc=-4.28mV=-3.03mVrms (Vc is the threshold of low power computation)
7'b111-1111, Vc=12.91mV=9.14mVrms
DAC typical resolution is [12.91-(-4.28)]/127=135.4μV=95.7μVrms
Address: 12H
Type: Read/Write
Default Value: 0000H
Bit Name Description
15 - Reserved.
14:8 CalCodeN
Channel 2 current negative detector calculation code.
Code mapping:
7'b000-0000, Vc=-4.28mV=-3.03mVrms (Vc is the threshold of low power computation)
7'b111-1111, Vc=12.91mV=9.14mVrms
DAC typical resolution is [12.91-(-4.28)]/127=135.4μV=95.7μVrms
7 - Reserved.
6:0 CalCodeP
Channel 2 current positive detector calculation code.
Code mapping:
7'b000-0000, Vc=-4.28mV=-3.03mVrms (Vc is the threshold of low power computation)
7'b111-1111, Vc=12.91mV=9.14mVrms
DAC typical resolution is [12.91-(-4.28)]/127=135.4μV=95.7μVrms
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DetectTh3
Channel 3 Current Threshold in Detection Mode
The calibration method is that, the user program the detection threshold and test with the standard input signal until the
output trips.
Address: 13H
Type: Read/Write
Default Value: 0000H
Bit Name Description
15 - Reserved.
14:8 CalCodeN
Channel 3 current negative detector calculation code.
Code mapping:
7'b000-0000, Vc=-4.28mV=-3.03mVrms (Vc is the threshold of low power computation)
7'b111-1111, Vc=12.91mV=9.14mVrms
DAC typical resolution is [12.91-(-4.28)]/127=135.4μV=95.7μVrms
7 - Reserved.
6:0 CalCodeP
Channel 3 current positive detector calculation code.
Code mapping:
7'b000-0000, Vc=-4.28mV=-3.03mVrms (Vc is the threshold of low power computation)
7'b111-1111, Vc=12.91mV=9.14mVrms
DAC typical resolution is [12.91-(-4.28)]/127=135.4μV=95.7μVrms
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52
6.3.2 PARTIAL MEASUREMENT MODE REGISTERS
PMOffsetA
Ioffset for phase A in Partial Measurement mode
PMOffsetB
Ioffset for phase B in Partial Measurement mode
PMOffsetC
Ioffset for phase C in Partial Measurement mode
PMPGA
PGAgain Configuration in Partial Measurement mode
PMIrmsA
Irms for phase A in Partial Measurement mode
Address: 14H
Type: Read/Write
Default Value: 0000H
Bit Name Description
15-14 - Reserved.
13:0 PMOffsetA Phase A current offset in Partial Measurement mode.
Address: 15H
Type: Read/Write
Default Value: 0000H
Bit Name Description
15-14 - Reserved.
13:0 PMOffsetB Phase B current offset in Partial Measurement mode.
Address: 16H
Type: Read/Write
Default Value: 0000H
Bit Name Description
15-14 - Reserved.
13:0 PMOffsetC Phase C current offset in Partial Measurement mode.
Address: 17H
Type: Read/Write
Default Value: 0000H
Bit Name Description
15-14 DPGA DPGA in Partial Measurement mode.
13:0 PGAGain PGAGain in Partial Measurement mode
Refer to the MMode1 register for encoding and mapping.
Address: 18H
Type: Read
Default Value: 0000H
Bit Name Description
15:0 PMIrmsA
*
Current RMS/mean result in Partial Measurement mode.
Format: It is unsigned for RMS while signed for mean value.
Note: For current measuring in Partial Measurement mode, current gain is suggested to realized by external MCU and current RMS value shall not
exceed 40A.
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PMIrmsB
Irms for phase B in Partial Measurement mode
PMIrmsC
Irms for phase C in Partial Measurement mode
PMConfig
Measure Configuration in Partial Measurement mode
PMAvgSamples
Number of 8K Samples to be Averaged
Address: 19H
Type: Read
Default Value: 0000H
Bit Name Description
15:0 PMIrmsB
*
Current RMS/mean result in Partial Measurement mode.
Format: It is unsigned for RMS while signed for mean value.
Note: For current measuring in Partial Measurement Mode, current gain is suggested to realized by external MCU and current RMS value shall not
exceed 40A.
Address: 1AH
Type: Read
Default Value: 0000H
Bit Name Description
15:0 PMIrmsC
*
Current RMS/mean result in Partial Measurement mode.
Format: It is unsigned for RMS while signed for mean value.
Note: For current measuring in Partial Measurement Mode, current gain is suggested to realized by external MCU and current RMS value shall not
exceed 40A.
Address: 1BH
Type: Read/Write
Default Value: 0000H
Bit Name Description
15 - Reserved.
14 ReMeasure This bit is ‘1’-write-only. Write ‘1’ to this bit will trigger another measurement cycle.
13 Measure-
StartZX
This bit configures start of measurement whether starts from zero crossing point.
0: Measurement start immediately (default)
1: Measurement start from zero-crossing point
12 MeasureType
This bit indicates the measurement type.
0: RMS measurement (default)
1: Mean Value (DC Average) measurement
11-1 - Reserved.
0PMBusy
This bit indicates the measure status. This bit is read-only.
0: Measurement done (default)
1: Measurement in progress
Address: 1CH
Type: Read
Default Value: 00A0H
Bit Name Description
15:0 - Number of 8K samples to be averaged in RMS/mean computation.
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PMIrmsLSB
LSB bits of PMRrms[A/B/C]
Address: 1DH
Type: Read
Default Value: 0000H
Bit Name Description
15:12 - Reserved.
11:8 IrmsCLSB These bits indicate LSB of the corresponding phase RMS measurement result if the MeasureType bit
(b12, PMConfig) =0.
These bits indicate MSB of the corresponding phase mean measurement result if the MeasureType bit
(b12, PMConfig) =1.
7:4 IrmsBLSB
3:0 IrmsALSB
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M90E36A [DATASHEET]
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6.4 CONFIGURATION AND CALIBRATION REGISTERS
6.4.1 START REGISTERS AND ASSOCIATED CHECKSUM OPERATION SCHEME
The Start Registers (ConfigStart (30H), CalStart (40H), HarmStart (50H) and AdjStart (60H)) and associated registers /
checksum have a special operation scheme to protect important configuration data, illustrated below in the diagram. Start
registers have multiple valid settings for different operation modes.
Figure-22 Start and Checksum Register Operation Scheme
Start Register Value Usage Operation
6886H Power up state It is the value after reset. This state blocks checksum checking error generation
5678H Calibration Similar like 6886H, This state blocks checksum checking error generation. Writing with this
value trigger a reset to the associated registers.
8765H Operation Checksum checking is enabled and if error detected, IRQ/Warn is asserted and Metering
stopped.
Other Error Force checksum error generation and system stop.
xxxStart register
Start Associated
Regisers
CheckSum
(computed)
Checksum
Computation
0
1
IRQ/WarnOut
Generation
Metering
Enable
0
1
Checksum
Error
Error
xxxStart = 5678H
xxxStart =
8765H
0
1
CheckSum
(programmed)
Compare Error?
User Write
User Read
⎯xxxStart refers to ConfigStart, CalStart, HarmStart and
AdjStart. Those registers and their assoicated checksum
computation has similar behavior.
⎯xxxStart registers’ reset value is 6886H.
⎯Writing 5678H to xxxStart register will trigger a reset to its
associated register. Register can be accessed after reset.
⎯xxxStart associated register is the register between
xxxStart and associated checksum
0
1
xxxStart =
6886H
0
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56
6.4.2 CONFIGURATION REGISTERS
ConfigStart
Configure Start Command
Table-5 Configuration Registers
Register
Address Register Name
Read/Write
Type Functional Description Power-on Value and Comments
Configuration Registers
*
30H ConfigStart R/W Calibration Start Command 6886H
31H PLconstH R/W High Word of PL_Constant 0861H
32H PLconstL R/W Low Word of PL_Constant C468H
33H MMode0 R/W HPF/Integrator On/off, CF and all-phase
energy computation configuration 0087H
34H MMode1 R/W PGA gain configuration 0000H
35H PStartTh R/W Active Startup Power Threshold.
16 bit unsigned integer, Unit: 0.00032 Watt 0000H.
36H QStartTh R/W Reactive Startup Power Threshold.
16 bit unsigned integer, Unit: 0.00032 var 0000H
37H SStartTh R/W Apparent Startup Power Threshold.
16 bit unsigned integer, Unit: 0.00032 VA 0000H
38H PPhaseTh R/W
Startup power threshold (for |P|+|Q| of a
phase) for any phase participating Active E
nergy Accumulation. Common for phase A/
B/C.
0000H
16 bit unsigned integer,
Unit: 0.00032 Watt/var
39H QPhaseTh R/W
Startup power threshold (for |P|+|Q| of a
phase) for any phase participating ReAc-
tive Energy Accumulation. Common for
phase A/B/C.
0000H
16bit unsigned integer,
Unit: 0.00032 Watt/var
3AH SPhaseTh RW
Startup power threshold (for |P|+|Q| of a
phase) for any phase participating Appar-
ent Energy Accumulation. Common for
phase A/B/C.
0000H
16 bit unsigned integer,
Unit: 0.00032 Watt/var
3BH CS0 R/W Checksum 0 Checksum register. 421CH
(calculated value after reset)
Note: For details, please refer to application note 46104.
Address: 30H
Type: Read/Write
Default Value: 6886H
Bit Name Description
15 - 0 CalStart[15:0] Refer to 6.4.1 Start Registers and Associated Checksum Operation Scheme.
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PLconstH
High Word of PL_Constant
PLconstL
Low Word of PL_Constant
Address: 31H
Type: Read/Write
Default Value: 0861H
Bit Name Description
15 - 0 PLcon-
stH[15:0]
The PLconstH[15:0] and PLconstL[15:0] bits are high word and low word of PL_Constant respectively.
PL_Constant is a constant which is proportional to the sampling ratios of voltage and current, and
inversely proportional to the Meter Constant. PL_Constant is a threshold for energy calculated inside the
chip, i.e., energy larger than PL_Constant will be accumulated as 0.01CFx in the corresponding energy
registers and then output on CFx if one CF reaches.
It is suggested to set PL_constant as a multiple of 4 so as to double or redouble Meter Constant in low
current state to save verification time.
Address: 32H
Type: Read/Write
Default Value: C468H
Bit Name Description
15 - 0 PLcon-
stL[15:0]
The PLconstH[15:0] and PLconstL[15:0] bits are high word and low word of PL_Constant respectively.
It is suggested to set PL_constant as a multiple of 4.
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MMode0
Metering method configuration
Address: 33H
Type: Read/Write
Default Value: 0087H
Bit Name Description
15-14 - Reserved.
13 I1I3Swap
This bit defines phase mapping for I1 and I3:
0: I1 maps to phase A, I3 maps to phase C (default)
1: I1 maps to phase C, I3 maps to phase A
Note: I2 always maps to phase B.
12 Freq60Hz
Current Grid operating line frequency.
0: 50Hz (default)
1: 60Hz
11 HPFOff Disable HPF in the signal processing path.
10 didtEn
Enable Integrator for didt current sensor.
0: disable (default)
1: enable
9 001LSB
Energy register LSB configuration for all energy registers:
0: 0.1CF (default)
1: 0.01CF
83P3W
This bit defines the voltage/current phase sequence detection mode:
0: 3P4W (default)
1: 3P3W (Ua is Uab, Uc is Ucb, Ub is not used)
7CF2varh
CF2 pin source:
0: apparent energy
1: reactive energy (default)
6 CF2ESV
This bit is to configure the apparent energy type in power factor calibration, and in CF2 output if apparent
energy is selected by setting CF2varh=0.
0:All-phase apparent energy arithmetic sum (default)
1:All-phase apparent energy vector sum
5 - Reserved.
4 ABSEnQ
These bits configure the calculation method of total (all-phase-sum) reactive/active energy and power:
0: Arithmetic sum: (default)
ET=EA*EnPA+ EB*EnPB+ EC*EnPC
PT= PA*EnPA+ PB*EnPB+ PC*EnPC
1: Absolute sum:
ET=|EA|*EnPA+ |EB|*EnPB+ |EC|*EnPC
PT=|PA|*EnPA+ |PB|*EnPB+ |PC|*EnPC
Note: ET is the total (all-phase-sum) energy, EA/EB/EC are the signed phase A/B/C energy respectively.
Reverse energy is negative. PT is the total (all-phase-sum) power, PA/PB/PC are the signed phase A/B/C
power respectively. Reverse power is negative.
3 ABSEnP
2EnPA
These bits configure whether Phase A/B/C are counted into the all-phase sum energy/power (P/Q/S).
1: Corresponding Phase A/B/C to be counted into the all-phase sum energy/power (P/Q/S) (default)
0: Corresponding Phase A/B/C not counted into the all-phase sum energy/power (P/Q/S)
1EnPB
0EnPC
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MMode1
PGA Gain Configuration
Address: 34H
Type: Read/Write
Default Value: 0000H
Bit Name Description
15-14 DPGA_GAIN
Digital PGA gain for the 4 current channels. This gain is implemented at the end of decimation filter.
00: Gain = 1 (default)
01: Gain = 2
10: Gain = 4
11: Gain = 8
13-0 PGA_GAIN
PGA gain for all ADC channels.
Mapping:
[13:12]: V3
[11:10]: V2
[9:8]: V1
[7:6]: I4
[5:4]: I3
[3:2]: I2
[1:0]: I1
Encoding:
00: 1X (default)
01: 2X
10: 4X
11: N/A
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60
CS0
Checksum 0
There are multiple Start register and Checksum (CS0/CS1/CS2/CS3) registers for different crucial register blocks. Those
registers are handled in the similar way.
Address: 3BH
Type: Read/Write
Default Value: 421CH
Bit Name Description
15 - 0 CS0[15:0]
This register should be written after the 31H-3AH registers are written. Suppose the high byte and the low
byte of the 31H-3AH registers are shown in the below table.
The calculation of the CS0 register is as follows:
The low byte of 3BH register is: L3B=MOD(H31+H32+...+H3A+L31+L32+...+L3A, 2^8)
The high byte of 3BH register is: H3B=H31 XOR H32 XOR... XOR H3A XOR L31 XOR L32 XOR... XOR L3A
The M90E36A calculates CS0 regularly. If the value of the CS0 register and the calculation by the M90E
36A is different when ConfigStart=8765H, the CS0Err bit (b14, SysStatus0) is set and the WarnOut and
IRQ pins are asserted.
Note: The readout value of the CS0 register is the calculation by the M90E36A, which is different from
what is written.
Register Address
High
Byte
Low
Byte
31H H31 L31
32H H32 L32
33H H33 L33
34H H34 L34
35H H35 L35
36H H36 L36
37H H37 L37
38H H38 L38
39H H39 L39
3AH H3A L3A
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M90E36A [DATASHEET]
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6.4.3 ENERGY CALIBRATION REGISTERS
PoffsetA
Phase A Active Power Offset
QoffsetA
Phase A Reactive Power Offset
Table-6 Calibration Registers
Register
Address Register Name
Read/Write
Type Functional Description Power-on Value
Calibration Registers
40H CalStart R/W Calibration Start Command 6886H
41H POffsetA R/W Phase A Active Power Offset 0000H
42H QOffsetA R/W Phase A Reactive Power Offset 0000H
43H POffsetB R/W Phase B Active Power Offset 0000H
44H QOffsetB R/W Phase B Reactive Power Offset 0000H
45H POffsetC R/W Phase C Active Power Offset 0000H
46H QOffsetC R/W Phase C Reactive Power Offset 0000H
47H GainA R/W Phase A Active/Reactive Energy cali-
bration gain 0000H
48H PhiA R/W Phase A calibration phase angle 0000H
49H GainB R/W Phase B Active/Reactive Energy cali-
bration gain 0000H
4AH PhiB R/W Phase B calibration phase angle 0000H
4BH GainC R/W Phase C Active/Reactive Energy cali-
bration gain 0000H
4CH PhiC R/W Phase C calibration phase angle 0000H
4DH CS1
*
R/W Checksum 1 0000H
Note: The calculation of the CS1 register is similar as the CS0 register by calculating the 41H-4CH registers. For details, please refer to
application note 46104.
Address: 41H
Type: Read/Write
Default Value: 0000H
Bit Name Description
15-0 Offset Power offset. Signed 16-bit integer.
Address: 42H
Type: Read/Write
Default Value: 0000H
Bit Name Description
15-0 Offset Power offset. Signed 16-bit integer.
M90E36A [Datasheet]
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62
GainA
Phase A Active/Reactive Energy calibration gain
PhiA
Phase A calibration phase angle
The phase B and phase C’s calibration registers are similar as phase A.
Address: 47H
Type: Read/Write
Default Value: 0000H
Bit Name Description
15-0 Gain
Energy calibration gain.
Signed integer.
Actual power gain = (1+ Gain)
Address: 48H
Type: Read/Write
Default Value: 0000H
Bit Name Description
15 DelayV 0: Delay Cycles are applied to current channel. (default)
1: Delay Cycles are applied to voltage channel.
14:10 - Reserved.
9:0 DelayCycles Unit is 2.048MHz cycle. It is an unsigned 10 bit integer.
63
M90E36A [DATASHEET]
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6.4.4 FUNDAMENTAL/HARMONIC ENERGY CALIBRATION REGISTERS
Table-7 Fundamental/Harmonic Energy Calibration Registers
Register
Address Register Name
Read/Write
Type Functional Description Power-on Value
50H HarmStart R/W Harmonic Calibration Startup Com-
mand 6886H
51H POffsetAF R/W Phase A Fundamental Active Power
Offset 0000H
52H POffsetBF R/W Phase B Fundamental Active Power
Offset 0000H
53H POffsetCF R/W Phase C Fundamental Active Power
Offset 0000H
54H PGainAF R/W Phase A Fundamental Active Power
Gain 0000H
55H PGainBF R/W Phase B Fundamental Active Power
Gain 0000H
56H PGainCF R/W Phase C Fundamental Active Power
Gain 0000H
57H CS2
*
R/W Checksum 2 0000H
Note: The calculation of the CS2 register is similar as the CS0 register by calculating the 51H-56H registers. For details, please refer to
application note 46104.
M90E36A [Datasheet]
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64
6.4.5 MEASUREMENT CALIBRATION
Table-8 Measurement Calibration Registers
Register
Address Register Name
Read/Write
Type Functional Description Power-on Value
60H AdjStart R/W Measurement Calibration Startup
Command 6886H
61H UgainA R/W Phase A Voltage RMS Gain CE40H
62H IgainA R/W Phase A Current RMS Gain 7530H
63H UoffsetA R/W Phase A Voltage RMS Offset 0000H
64H IoffsetA R/W Phase A Current RMS Offset 0000H
65H UgainB R/W Phase B Voltage RMS Gain CE40H
66H IgainB R/W Phase B Current RMS Gain 7530H
67H UoffsetB R/W Phase B Voltage RMS Offset 0000H
68H IoffsetB R/W Phase B Current RMS Offset 0000H
69H UgainC R/W Phase C Voltage RMS Gain CE40H
6AH IgainC R/W Phase C Current RMS Gain 7530H
6BH UoffsetC R/W Phase C Voltage RMS Offset 0000H
6CH IoffsetC R/W Phase C Current RMS Offset 0000H
6DH IgainN R/W Sampled N line Current RMS Gain 7530H
6EH IoffsetN R/W Sampled N line Current RMS Offset 0000H
6FH CS3
*
R/W Checksum 3 8EBEH
Note: The calculation of the CS3 register is similar as the CS0 register by calculating the 61H-6EH registers.
65
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
6.5 ENERGY REGISTER
6.5.1 REGULAR ENERGY REGISTERS
Table-9 Regular Energy Registers
Register
Address Register Name
Read/Write
Type Functional Description Comment
80H APenergyT R/C Total Forward Active Energy
Resolution is 0.1CF/0.01CF. 0.01CF /
0.1CF setting is defined by the 001LSB
bit (b9, MMode0). Cleared after read.
81H APenergyA R/C Phase A Forward Active Energy
82H APenergyB R/C Phase B Forward Active Energy
83H APenergyC R/C Phase C Forward Active Energy
84H ANenergyT R/C Total Reverse Active Energy
85H ANenergyA R/C Phase A Reverse Active Energy
86H ANenergyB R/C Phase B Reverse Active Energy
87H ANenergyC R/C Phase C Reverse Active Energy
88H RPenergyT R/C Total Forward Reactive Energy
89H RPenergyA R/C Phase A Forward Reactive Energy
8AH RPenergyB R/C Phase B Forward Reactive Energy
8BH RPenergyC R/C Phase C Forward Reactive Energy
8CH RNenergyT R/C Total Reverse Reactive Energy
8DH RNenergyA R/C Phase A Reverse Reactive Energy
8EH RNenergyB R/C Phase B Reverse Reactive Energy
8FH RNenergyC R/C Phase C Reverse Reactive Energy
90H SAenergyT R/C Total (Arithmetic Sum) Apparent E
nergy
91H SenergyA R/C Phase A Apparent Energy
92H SenergyB R/C Phase B Apparent Energy
93H SenergyC R/C Phase C Apparent Energy
94H SVenergyT R/C (Vector Sum) Total Apparent Energy
95H EnStatus0 R Metering Status 0
96H EnStatus1 R Metering Status 1
98H SVmeanT R (Vector Sum) Total Apparent Power Complement, MSB is always ‘0’;
XX.XXX kVA
99H SVmeanTLSB R LSB of (Vector Sum) Total Apparent
Power
LSB of SVmeanT. Unit/LSB is 4/65536
VA
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66
EnStatus0
Metering Status 0
EnStatus1
Metering Status 1
Address: 95H
Type: Read
Default Value: F000H
Bit Name Description
15 TQNoload all-phase-sum reactive power no-load condition detected.
14 TPNoload all-phase-sum active power no-load condition detected.
13 TASNoload all-phase-sum apparent power no-load condition detected.
12 TVSNoload all-phase-sum vectored sum apparent active power no-load condition detected.
11-4 - Reserved.
3 CF4RevFlag
CF4/CF3/CF2/CF1 Forward/Reverse Flag – reflect the direction of the current CF pulse.
0: Forward (default)
1: Reverse
2 CF3RevFlag
1 CF2RevFlag
0 CF1RevFlag
Address: 96H
Type: Read
Default Value: 0000H
Bit Name Description
15-7 - Reserved.
6 SagPhaseA These bits indicate whether there is voltage sag on phase A, B or C respectively.
0: no voltage sag (default)
1: voltage sag
5 SagPhaseB
4 SagPhaseC
3 - Reserved.
2 PhaseLossA These bits indicate whether there is a phase loss in Phase A/B/C.
0: no phase loss (default)
1: phase loss.
1 PhaseLossB
0 PhaseLossC
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M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
6.5.2 FUNDAMENTAL / HARMONIC ENERGY REGISTER
Table-10 Fundamental / Harmonic Energy Register
Register
Address Register Name
Read/Write
Type Functional Description Comment
A0H APenergyTF R/C Total Forward Active Fundamental E
nergy
Resolution is 0.1CF / 0.01CF. 0.01CF /
0.1CF setting is defined by the 001LSB
bit (b9, MMode0). Cleared after read.
A1H APenergyAF R/C Phase A Forward Active Fundamental
Energy
A2H APenergyBF R/C Phase B Forward Active Fundamental
Energy
A3H APenergyCF R/C Phase C Forward Active Fundamen-
tal Energy
A4H ANenergyTF R/C Total Reverse Active Fundamental E
nergy
A5H ANenergyAF R/C Phase A Reverse Active Fundamen-
tal Energy
A6H ANenergyBF R/C Phase B Reverse Active Fundamen-
tal Energy
A7H ANenergyCF R/C Phase C Reverse Active Fundamental
Energy
A8H APenergyTH R/C Total Forward Active Harmonic Energy
A9H APenergyAH R/C Phase A Forward Active Harmonic E
nergy
AAH APenergyBH R/C Phase B Forward Active Harmonic E
nergy
ABH APenergyCH R/C Phase C Forward Active Harmonic E
nergy
ACH ANenergyTH R/C Total Reverse Active Harmonic Energy
ADH ANenergyAH R/C Phase A Reverse Active Harmonic E
nergy
AEH ANenergyBH R/C Phase B Reverse Active Harmonic E
nergy
AFH ANenergyCH R/C Phase C Reverse Active Harmonic E
nergy
M90E36A [Datasheet]
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68
6.6 MEASUREMENT REGISTERS
6.6.1 POWER AND POWER FACTOR REGISTERS
Table-11 Power and Power Factor Register
Register
Address Register Name
Read/Write
Type Functional Description Comment
B0H PmeanT R Total (all-phase-sum) Active Power Complement, MSB as the sign bit
XX.XXX kW
1LSB corresponds to 1Watt for phase A/
B/C, and 4Watt for Total (all-phase-sum)
B1H PmeanA R Phase A Active Power
B2H PmeanB R Phase B Active Power
B3H PmeanC R Phase C Active Power
B4H QmeanT R Total (all-phase-sum) Reactive Power Complement, MSB as the sign bit
XX.XXX kvar
1LSB corresponds to 1var for phase A/
B/C, and 4var for Total (all-phase-sum)
B5H QmeanA R Phase A Reactive Power
B6H QmeanB R Phase B Reactive Power
B7H QmeanC R Phase C Reactive Power
B8H SAmeanT R Total (Arithmetic Sum) apparent power Complement, MSB always '0'
XX.XXX kVA
1LSB corresponds to 1va for phase A/B/
C, and 4va for Total (all-phase-sum)
B9H SmeanA R phase A apparent power
BAH SmeanB R phase B apparent power
BBH SmeanC R phase C apparent power
BCH PFmeanT R Total power factor Signed, MSB as the sign bit
X.XXX
LSB is 0.001. Range from -1000 to
+1000
BDH PFmeanA R phase A power factor
BEH PFmeanB R phase B power factor
BFH PFmeanC R phase C power factor
C0H PmeanTLSB R Lower word of Total (all-phase-sum)
Active Power
Lower word of Active Powers.
1LLSB
*
corresponds to 4/256 Watt
C1H PmeanALSB R Lower word of Phase A Active Power
Lower word of Active Powers.
1LLSB corresponds to 1/256 Watt
C2H PmeanBLSB R Lower word of Phase B Active Power
C3H PmeanCLSB R Lower word of Phase C Active Power
C4H QmeanTLSB R Lower word of Total (all-phase-sum)
Reactive Power
Lower word of ReActive Powers.
1LLSB corresponds to 4/256 var
C5H QmeanALSB R Lower word of Phase A Reactive
Power
Lower word of ReActive Powers.
1LLSB corresponds to 1/256 var
C6H QmeanBLSB R Lower word of Phase B Reactive
Power
C7H QmeanCLSB R Lower word of Phase C Reactive
Power
C8H SAmeanTLSB R Lower word of Total (Arithmetic Sum)
apparent power
Lower word of Apparent Powers.
1LLSB corresponds to 4/256 VA
C9H SmeanALSB R Lower word of phase A apparent
power
Lower word of Apparent Powers.
1LLSB corresponds to 1/256 VA
CAH SmeanBLSB R Lower word of phase B apparent
power
CBH SmeanCLSB R Lower word of phase C apparent
power
Note: All the lower 8 bits of C0H-CBH registers and E0H-EFH registers are always zero. Only the higher 8 bits of these registers are
valid.
In this document, LLSB means bit 8 of the lower registers as below:
b15 b14 b13 b12 b11 b10 b9 b8
(LLSB) b7 b6 b5 b4 b3 b2 b1 b0
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M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
6.6.2 FUNDAMENTAL/ HARMONIC POWER AND VOLTAGE/ CURRENT RMS REGISTERS
Table-12 Fundamental/ Harmonic Power and Voltage/ Current RMS Registers
Register
Address Register Name
Read/Write
Type Functional Description Comment
D0H PmeanTF R Total active fundamental power
Complement, 16-bit integer with unit of
4Watt.
1LSB corresponds to 4Watt
D1H PmeanAF R phase A active fundamental power Complement, 16-bit integer with unit of
1Watt.
1LSB corresponds to 1Watt
D2H PmeanBF R phase B active fundamental power
D3H PmeanCF R phase C active fundamental power
D4H PmeanTH R Total active harmonic power
Complement, 16-bit integer with unit of
4Watt.
1LSB corresponds to 4Watt
D5H PmeanAH R phase A active harmonic power Complement, 16-bit integer with unit of
1Watt.
1LSB corresponds to 1Watt
D6H PmeanBH R phase B active harmonic power
D7H PmeanCH R phase C active harmonic power
D8H IrmsN1 R N Line Sampled current RMS
unsigned 16-bit integer with unit of
0.001A
1LSB corresponds to 0.001 A
D9H UrmsA R phase A voltage RMS
1LSB corresponds to 0.01 VDAH UrmsB R phase B voltage RMS
DBH UrmsC R phase C voltage RMS
DCH IrmsN0 R N Line calculated current RMS
unsigned 16-bit integer with unit of
0.001A
1LSB corresponds to 0.001 A
DDH IrmsA R phase A current RMS
DEH IrmsB R phase B current RMS
DFH IrmsC R phase C current RMS
E0H PmeanTFLSB R Lower word of Total active fundamen-
tal Power
Lower word of D0H register.
1LLSB
*
corresponds to 4/256 Watt
E1H PmeanAFLSB R Lower word of phase A active funda-
mental Power
Lower word of registers from D1H to
D3H.
1LLSB corresponds to 1/256 Watt
E2H PmeanBFLSB R Lower word of phase B active funda-
mental Power
E3H PmeanCFLSB R Lower word of phase C active funda-
mental Power
E4H PmeanTHLSB R Lower word of Total active harmonic
Power
Lower word of D4H register.
1LLSB corresponds to 4/256 Watt
E5H PmeanAHLSB R Lower word of phase A active har-
monic Power
Lower word of registers from D5H to
D7H.
1LLSB corresponds to 1/256 Watt
E6H PmeanBHLSB R Lower word of phase B active har-
monic Power
E7H PmeanCHLSB R Lower word of phase C active har-
monic Power
E9H UrmsALSB R Lower word of phase A voltage RMS Lower word of registers from D9H to
DBH.
1LLSB corresponds to 0.01/256V
EAH UrmsBLSB R Lower word of phase B voltage RMS
EBH UrmsCLSB R Lower word of phase C voltage RMS
EDH IrmsALSB R Lower word of phase A current RMS Lower word of registers from DDH to
DFH.
1LLSB corresponds to 0.001/256A
EEH IrmsBLSB R Lower word of phase B current RMS
EFH IrmsCLSB R Lower word of phase C current RMS
M90E36A [Datasheet]
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70
6.6.3 THD+N, FREQUENCY, ANGLE AND TEMPERATURE REGISTERS
Note: All the lower 8 bits of C0H-CBH registers and E0H-EFH registers are always zero. Only the higher 8 bits of these registers are
valid.
In this document, LLSB means bit 8 of the lower registers as below:
Table-13 THD+N, Frequency, Angle and Temperature Registers
Register
Address Register Name
Read/Write
Type Functional Description Comment
F1H THDNUA R phase A voltage THD+N
1LSB corresponds to 0.01%F2H THDNUB R phase B voltage THD+N
F3H THDNUC R phase C voltage THD+N
F5H THDNIA R phase A current THD+N
1LSB corresponds to 0.01%F6H THDNIB R phase B current THD+N
F7H THDNIC R phase C current THD+N
F8H Freq R Frequency 1LSB corresponds to 0.01 Hz
F9H PAngleA R phase A mean phase angle Signed, MSB as the sign bit
1LSB corresponds to 0.1-degree,
-180.0°~+180.0°
FAH PAngleB R phase B mean phase angle
FBH PAngleC R phase C mean phase angle
FCH Temp R Measured temperature 1LSB corresponds to 1 °C
Signed, MSB as the sign bit
FDH UangleA R phase A voltage phase angle Always ‘0’
FEH UangleB R phase B voltage phase angle Signed, MSB as the sign bit
Take phase A voltage as base voltage
1LSB corresponds to 0.1 degree,
-180.0°~+180.0°
FFH UangleC R phase C voltage phase angle
Table-12 Fundamental/ Harmonic Power and Voltage/ Current RMS Registers (Continued)
Register
Address Register Name
Read/Write
Type Functional Description Comment
b15 b14 b13 b12 b11 b10 b9 b8
(LLSB) b7 b6 b5 b4 b3 b2 b1 b0
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M90E36A [DATASHEET]
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6.7 HARMONIC FOURIER ANALYSIS REGISTERS
Table-14 Harmonic Fourier Analysis Results Registers
Register
Address Register Name
Read/Write
Type Functional Description Comment
100H AI_HR2 R phase A, Current, Harmonic Ratio for
2-th order component
Harmonic Ratio (%) = Register Value /
163.84
101H AI_HR3 R phase A, Current, Harmonic Ratio for
3-th order component
102H AI_HR4 R phase A, Current, Harmonic Ratio for
4-th order component
… R
11EH AI_HR32 R phase A, Current, Harmonic Ratio for
32-th order component
11FH AI_THD R phase A, Current, Total Harmonic Dis-
tortion Ratio
120H BI_HR2 R phase B, Current, Harmonic Ratio for
2-th order component
Harmonic Ratio (%) = Register Value /
163.84
121H BI_HR3 R phase B, Current, Harmonic Ratio for
3-th order component
122H BI_HR4 R phase B, Current, Harmonic Ratio for
4-th order component
… R
13EH BI_HR32 R phase B, Current, Harmonic Ratio for
32-th order component
13FH BI_THD R phase B, Current, Total Harmonic Dis-
tortion Ratio
140H CI_HR2 R phase C, Current, Harmonic Ratio for
2-th order component
Harmonic Ratio (%) = Register Value /
163.84
141H CI_HR3 R phase C, Current, Harmonic Ratio for
3-th order component
142H CI_HR4 R phase C, Current, Harmonic Ratio for
4-th order component
… R
15EH CI_HR32 R phase C, Current, Harmonic Ratio for
32-th order component
15FH CI_THD R phase C, Current, Total Harmonic Dis-
tortion Ratio
160H AV_HR2 R phase A, Voltage, Harmonic Ratio for
2-th order component
Harmonic Ratio (%) = Register Value /
163.84
161H AV_HR3 R phase A, Voltage, Harmonic Ratio for
3-th order component
162H AV_HR4 R phase A, Voltage, Harmonic Ratio for
4-th order component
… R
17EH AV_HR32 R phase A, Voltage, Harmonic Ratio for
32-th order component
17FH AV_THD R phase A, Voltage, Total Harmonic Dis-
tortion Ratio
M90E36A [Datasheet]
Atmel-46004B-SE-M90E36A-Datasheet_021215
72
180H BV_HR2 R phase B, Voltage, Harmonic Ratio for
2-th order component
Harmonic Ratio (%) = Register Value /
163.84
181H BV_HR3 R phase B, Voltage, Harmonic Ratio for
3-th order component
182H BV_HR4 R phase B, Voltage, Harmonic Ratio for
4-th order component
… R
19EH BV_HR32 R phase B, Voltage, Harmonic Ratio for
32-th order component
19FH BV_THD R phase B, Voltage, Total Harmonic Dis-
tortion Ratio
1A0H CV_HR2 R phase C, Voltage, Harmonic Ratio for
2-th order component
Harmonic Ratio (%) = Register Value /
163.84
1A1H CV_HR3 R phase C, Voltage, Harmonic Ratio for
3-th order component
1A2H CV_HR4 R phase C, Voltage, Harmonic Ratio for
4-th order component
… R
1BEH CV_HR32 R phase C, Voltage, Harmonic Ratio for
32-th order component
1BFH CV_THD R phase C, Voltage, Total Harmonic Dis-
tortion Ratio
1C0H AI_FUND R phase A, Current, Fundamental com-
ponent value
Current, Fundamental component value
= Register Value * 3.2656*10
-3
/ 2^scale,
Register (1C0H, 1C2H, 1C4H);
Voltage, Fundamental component value
= Register Value * 3.2656*10
-2
/ 2^scale,
Register (1C1H, 1C3H, 1C5H).
The scale is defined by the DFT_SCALE
(1D0H) register.
1C1H AV_FUND R phase A, Voltage, Fundamental com-
ponent value
1C2H BI_FUND R phase B, Current, Fundamental com-
ponent value
1C3H BV_FUND R phase B, Voltage, Fundamental com-
ponent value
1C4H CI_FUND R phase C, Current, Fundamental com-
ponent value
1C5H CV_FUND R phase C, Voltage, Fundamental com-
ponent value
1D0H DFT_SCALE RW
Input Gain = 2^Scale, i.e. Scale = # of
bit shifts
[2:0]: Scale for Channel A-I.
[5:3]: Scale for Channel B-I.
[8:6]: Scale for Channel C-I.
[10:9]: Scale for Channel A-V.
[12:11]: Scale for Channel B-V.
[14:13]: Scale for Channel C-V.
[15]: Window disable. ‘1’ disable the
Hanning window.
Input data is scaled before sampling or
DFT.
1D1H DFT_CTRL RW
Bit[0]: DFT_START.
0: Reset and abort the DFT computa-
tion.
1: Start the DFT. This bit is automati-
cally cleared after DFT finishes.
Table-14 Harmonic Fourier Analysis Results Registers
Register
Address Register Name
Read/Write
Type Functional Description Comment
73
M90E36A [DATASHEET]
Atmel-46004B-SE-M90E36A-Datasheet_021215
7 ELECTRICAL SPECIFICATION
7.1 ELECTRICAL SPECIFICATION
Parameter Min Typ Max Unit Test Condition/ Comments
Accuracy
DC Power Supply Rejection Ratio (PSRR)
note 1
±0.1 %VDD=3.3V±0.3V, I=5A, V=220V, CT 1000:1,
sampling resistor 4.8Ω
AC Power Supply Rejection Ratio (PSRR)
note 1
±0.1 %VDD=3.3V superimposes 400mVrms, I=5A,
V=220V, CT 1000:1, sampling resistor 4.8Ω
Active Energy Error (Dynamic Range 6000:1) ±0.1 % CT 1000:1, sampling resistor 4.8Ω
ADC Channel
Differential Input Voltage
note 1
0.12
0.07
0.04
720
360
180
mVrms
PGA=1
PGA=2
PGA=4
Analog Input Pin Absolute Voltage Range GND-300 VDD-
1200 mV
Channel Input Impedance
120
80
50
KΩ
PGA=1
PGA=2
PGA=4
Channel Sampling Frequency 8 kHz
Channel Sampling Bandwidth 2 kHz
Temperature Sensor and Reference
Temperature Sensor Accuracy 1°C
Reference voltage 1.2 3.3 V, 25 °C
Reference voltage temperature coefficient
note 1
6 15 ppm/°C From -40 to 85 °C
Current detectors
Current Detector threshold range 2 3 4 mVrms 3.3 V, 25 °C
Current Detector threshold setting step/ resolu-
tion 0.096 mVrms 3.3 V, 25 °C
Current Detector detection time (single-side) 32 ms
Current Detector detection time (double-side) 17 ms
Crystal Oscillator
Oscillator Frequency (fsys_clk) 16.384 MHz
The Accuracy of crystal or external clock is
±20 ppm, 10pF ~ 20pF crystal load capacitor
integrated.
Power Supply
AVDD 2.8 3.3 3.6
DVDD 2.8 3.3 3.6
VDD18 1.8 V
Operating Currents
Normal mode operating current (I-Normal) 23 mA 3.3 V, 25 °C
Normal mode operating current with DFT engine
on
(I-Normal + DFT)
23.5 mA 3.3 V, 25 °C
Idle mode operating current (I-Idle) 0.1 4 μA
Detection mode operating current (I-Detection) 180
100
250
140 μADouble-side detection (at 3.3 V, 25 °C)
Single-side detection (at 3.3 V, 25 °C)
M90E36A [Datasheet]
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74
Partial Measurement mode operating current
(I-Measurement) 6.8 mA 3.3 V, 25°C
SPI
Slave mode (SPI) bit rate 100 1200k
note 2
bps
Master mode (DMA) bit rate 1800k bps
ESD
Machine Model (MM) 400 V JESD22-A115
Charged Device Model (CDM) 1000 V JESD22-C101
Human Body Model (HBM) 6000 V JESD22-A114
Latch Up ±100 mA JESD78A
Latch Up 5.4 V JESD78A
DC Characteristics
Digital Input High Level (all digital pins except
OSCI) 2.4 VDD V VDD=3.3V
Digital Input Low Level (all digital pins except
OSCI) 0.8 V VDD=3.3V
Digital Input Leakage Current ±1μA VDD=3.6V, VI=VDD or GND
Digital Output Low Level (CF1, CF2, CF3, CF4) 0.4 V VDD=3.3V, IOL=8mA
Digital Output Low Level (IRQ0, IRQ1, WarnOut,
ZX0, ZX1, ZX2, SDO) 0.4 V VDD=3.3V, IOL=5mA
Digital Output High Level (CF1, CF2, CF3, CF4) 2.8 V VDD=3.3V, IOH=-8mA, by separately
Digital Output High Level (IRQ0, IRQ1, War-
nOut, ZX0, ZX1, ZX2, SDO) 2.8 V VDD=3.3V, IOH=-5mA, by separately
Note 1: Guaranteed by characterization, not production tested.
Note 2: The maximum SPI bit rate during current detector calibration is 900k bps.
Parameter Min Typ Max Unit Test Condition/ Comments
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7.2 METERING/ MEASUREMENT ACCURACY
7.2.1 METERING ACCURACY
Metering accuracy or energy accuracy is calculated with relative error:
Where Emea is the energy measured by the meter, Ereal is the actual energy measured by a high accurate normative
meter.
Energy Type Energy Pulse
ADC Range
When Gain=1 Metering Accuracy
note
Active energy
(Per phase and all-phase-sum) CF1
PF=1.0 120μV-720mV
0.1%PF=0.5L, 180μV-720mV
PF=0.8C, 150μV-720mV
Reactive energy
(Per phase and all-phase-sum) CF2
sinФ=1.0 120μV-720mV
0.2%sinФ=0.5L, 180μV-720mV
sinФ=0.8C, 150μV-720mV
Apparent energy
(Per phase and arithmetic all-phase-
sum)
CF2 600μV-720mV
note 2
0.2%
Apparent energy (Vector sum) CF2 120μV-720mV 0.5%
Fundamental active energy
(Per phase and all-phase-sum) CF3
PF=1.0 120μV-720mV
0.2%PF=0.5L, 180μV-720mV
PF=0.8C, 150μV-720mV
Harmonic active energy
(Per phase and all-phase-sum) CF4
PF=1.0 120μV-720mV
0.5%PF=0.5L, 180μV-720mV
PF=0.8C, 150μV-720mV
Note 1: All the parameters in this table is tested on Atmel’s test platform.
Note 2: Apparent energy is tested using active energy with unity power factor since there’s no standard for apparent energy. Signal
below 600 μV is not tested.
%100×
−
=
real
realmea
E
EE
γ
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7.2.2 MEASUREMENT ACCURACY
The measurements are all calculated with fiducial error except for frequency and THD.
Fiducial error is calculated as follows:
Where Umea means the measured data of one measurement parameter, and Ureal means the real/actual data of the
parameter,
UFV means the fiducial value of this measurement parameter, which can be defined as Table-15.
For the above mentioned parameters, the measurement accuracy requirement is 0.5% maximum.
For frequency, temperature, THD+N, THD and Harmonic analysis:
Parameter Accuracy
Frequency: 0.01Hz
Temperature: 1 °C
THD/Harmonics: 5% relative error
Accuracy of all orders of harmonics: 5% relative error
Table-15 Measurement Parameter Range and Format
Measurement Fiducial Value (FV)
M90E36A
Defined
Format Range Comment
Voltage reference voltage Un XXX.XX 0 ~ 655.35V Unsigned integer with unit of 0.01V
Current
maximum current
Imax (4×In is recom-
mended)
XX.XXX 0 ~ 65.535A Unsigned integer with unit of 0.001A
Voltage rms Un XXX.XX 0 ~ 655.35V Unsigned integer with unit of 0.01V
Current rms
note 1
Ib/In XX.XXX 0 ~ 65.535A Unsigned integer with unit of 0.001A
Active/ Reactive Power
note 1
Un×4Ib XX.XXX -32.768 ~ +32.767 kW/
kvar
Signed integer with unit/LSB of 1
Watt/var
Apparent Power Un×4Ib XX.XXX 0 ~ +32.767 kVA Unsigned integer with unit/LSB of 1
VA
Frequency Reference Fre-
quency 50 Hz XX.XX 45.00~65.00 Hz Signed integer with unit/LSB of
0.01Hz
Power Factor 1.000 X.XXX -1.000 ~ +1.000 Signed integer, LSB/Unit = 0.001
Phase Angle
note 2
180ºXXX.X -180º ~ +180ºSigned integer, unit/LSB = 0.1º
THD+N
Relative error is
adopted, no Fiducial
Value
XX.XX 0.00%-99.99% Unit is 0.01%
THD 0.00%-399% Arithmetic ratio, 2 bit integer and 14
bit fractional.
Harmonic Component 0.00%-399%
Note 1:
All registers are of 16-bit. For cases when the current or active/reactive/apparent power goes beyond the above range, it is suggested
to be handled by MCU in application. For example, register value can be calibrated to 1/2 of the actual value during calibration, then
multiply 2 in application.
Note 2:
Phase angle is obtained when voltage/current crosses zero at the sampling frequency of 256kHz.
100%*
U
U-U
rrorFiducial_E
FV
realmea
=
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Harmonic component% =
Where
means the measuring value of the h
th
harmonic voltage/current;
means the given or actual value of the h
th
harmonic voltage/current.
100
iu
iuiu
hN
hNh ×
−
)(
)()(
h
iu )(
hN
iu )(
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7.3 INTERFACE TIMING
7.3.1 SPI INTERFACE TIMING (SLAVE MODE)
The SPI interface timing is as shown in Figure-23 and Table-16.
Figure-23 SPI Timing Diagram
Table-16 SPI Timing Specification
Symbol Description Min. Typical Max. Unit
tCSH Minimum CS High Level Time 2T
note 1
+10 ns
tCSS CS Setup Time 2T+10 ns
tCSD CS Hold Time 3T+10 ns
tCLD Clock Disable Time 1T ns
tCYC SCLK cycle 7T+10 ns
tCLH Clock High Level Time 5T+10 ns
tCLL Clock Low Level Time 2T+10 ns
tDIS Data Setup Time 2T+10 ns
tDIH Data Hold Time 1T+10 ns
tDW Minimum Data Width 3T+10 ns
tPD Output Delay 2T+20 ns
tDF Output Disable Time 2T+20 ns
Note:
1. T means system clock cycle. T=1/fsys_clk
CS
SCLK
SDI
SDO
tCSH
tCSS
High Impedance High Impedance
tCSD
tCLH tCLL
tDIS tDIH
tPD tDF
Valid Input
Valid Output
tCLD
tDW
tCYC
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7.3.2 DMA TIMING (MASTER MODE)
The DMA timing is as shown in Figure-24 and Table-17.
Figure-24 DMA Timing Diagram
Table-17 DMA Timing Specification
Symbol Description Min. Typical Max. Unit
tPD Output Delay 50 ns
SCLK
(CLK_IDLE=0)
SCLK
(CLK_IDLE=1)
SDI/SDO
CS
tPD
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7.4 POWER ON RESET TIMING
In most case, the power of M90E36A and MCU are both derived from 220V power lines. To make sure M90E36A is reset
and can work properly, MCU must force M90E36A into idle mode firstly and then into normal mode. In this operation, RESE
T is held to high in idle mode and de-asserted by delay T1 after idle-normal transition. Refer to Figure-25.
Figure-25 Power On Reset Timing (M90E36A and MCU are Powered on Simultaneously)
Figure-26 Power On Reset Timing in Normal & Partial Measurement Mode
Table-18 Power On Reset Specification
Symbol Description Min Typ Max Unit
VHPower On Trigger Voltage 2.5 2.7 V
T0
Duration forced in idle mode after power
on 1 ms
T1
Delay time after power on or exit idle
mode 5 16 40 ms
PM[1:0] Idle Mode Normal Mode
DVDD
MCU startup
RESET
T1
T0
DVDD
RESET
T1
VH
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7.5 ZERO-CROSSING TIMING
Figure-27 Zero-Crossing Timing Diagram (per phase)
Table-19 Zero-Crossing Specification
Symbol Description Min Typ Max Unit
TZX High Level Width 5 ms
TDDelay Time 0.2 0.5 ms
ZX
(Positive zero-crossing)
ZX
(Negative zero-crossing)
ZX
(All zero-crossing)
TZX
TD
V
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7.6 VOLTAGE SAG AND PHASE LOSS TIMING
Figure-28 Voltage Sag and Phase Loss Timing Diagram
time
Voltage
+ threshold
- threshold
IRQ (if enabled)
11ms window Sag/Phase Loss condition found
in two consecutive windows
Assert of
Voltage Sag / Phase Loss
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7.7 ABSOLUTE MAXIMUM RATING
Parameter Maximum Limit
Relative Voltage Between AVDD and AGND -0.3V~3.7V
Relative Voltage Between DVDD and DGND -0.3V~3.7V
Analog Input Voltage
(I1P, I1N, I2P, I2N, I3P, I3N, I4P, I4N, V1P, V1N, V2P, V2N, V3P, V3N) -0.6V~AVDD
Digital Input Voltage -0.3V~3.6V
Operating Temperature Range -50~120 °C
Maximum Junction Temperature 150 °C
Package Type Thermal Resistance θJA Unit Condition
TQFP48 58.5 °C/W No Airflow
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ORDERING INFORMATION
Atmel Ordering Code Package Carrier Temperature Range
ATM90E36A-AU-R TQFP48 Tape&Reel Industry (-40°C to +85°C)
ATM90E36A-AU-Y TQFP48 Tray Industry (-40°C to +85°C)
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PACKAGE DIMENSIONS
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REVISION HISTORY
Doc. Rev. Date Comments
46004A 05/22/2014 Initial document release in Atmel.
46004B 02/12/2015 Changed from Preliminary Datasheet to Datasheet.
Added notes to section 6.1.
X
XXX
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© 2015 Atmel Corporation. All rights reserved. / Rev.: Atmel-46004B-SE-M90E36A-Datasheet_021215.
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