1
®
FN3612.10
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or1-888-468-3774 |Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2003, 2005-2006. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
HI7190
24-Bit, High Precision, Sigma Delta A/D
Converter
The Intersil HI7190 is a monolithic instrumentation, sigma
delta A/D converter which operates from ±5V supplies. Both
the signal and reference inputs are fully differential fo r
maximum flexibility and performance. An internal
Programmable Gain Instrumentation Amplifier (PGIA)
provides input gains from 1 to 128 eli mi nating the need for
external pre-amplifiers. The on-demand converter auto-
calibrate function is capable of removing offset and gain
errors existing in external and internal circuitry . The on-board
user programmable digital filter provides over 120dB of
60/50Hz noise rejection and allows fine tuning of resolution
and conversion speed over a wide dynamic range. T he
HI7190 and HI7191 are functionally the same device, but the
HI7190 has tighter linearity specifications.
The HI7190 contains a serial I/O port and is compatible with
most synchronous transfer formats including both the
Motorola 6805/11 series SPI and Intel 8051 series SSR
protocols. A sophisticated set of commands gives the user
control over calibration, PGIA gain, device selection, standby
mode, and several other features. The On-chip Cal ibration
Registers allow the user to read and write calibration data.
Pinout HI7190
20 LD SOIC, PDIP
TOP VIEW
Features
• 22-Bit Resolution with No Missing Code
• 0.0007% Integral Non-Linearity (Typ)
• 20mV to ±2.5V Full Scale Input Ranges
• Internal PGIA with Gains of 1 to 128
• Serial Data I/O Interface, SPI Compatible
• Differential Analog and Reference Inputs
• Internal or System Calibration
• 120dB Rejection of 60/50Hz Line Noise
• Settling Time of 4 Conversions (Max) for a Step Input
• Pb-Free Plus Anneal Available (RoHS Compliant)
Applications
• Process Control and Measurement
• Industrial Weight Scales
• Part Counting Scales
• Laboratory Instrumentation
• Seismic Monitoring
• Magnetic Field Monitoring
• Additional Reference Literature
- Technical Brief, TB348 “HI7190/1 Negative Full Scale
Error vs Conversion Frequency”
- Application Note, AN9504 “A Brief Intro to Sigma Delta
Conversion”
- Technical Brief, TB329 “Intersil Sigma Delta Calibration
Technique”
- Application Note, AN9505 “Using the HI7190 Evaluation
Kit”
- Technical Brief, TB331 “Using the HI7190 Serial
Interface”
- Application Note, AN9527 “Interfacing HI7190 to a
Microcontroller”
- Application Note, AN9532 “Using HI7190 in a
Multiplexed System”
- Application Note, AN9601 “Using HI7190 with a Single
+5V Supply”
11
12
13
14
15
16
17
18
20
19
10
9
8
7
6
5
4
3
2
1
SCLK
SDO
SDIO
CS
DRDY
DGND
VRLO
AVSS
VRHI
VCM
MODE
RESET
OSC1
OSC2
SYNC
DVDD
AGND
AVDD
VINHI
VINLO
Data Sheet June 27, 2006
2FN3612.10
June 27, 2006
Functional Block Diagram
Ordering Information
PART
NUMBER PART
MARKING
TEMP.
RANGE
(°C) PACKAGE PKG.
DWG. #
HI7190IP HI7190IP -40 to 85 20 Ld PDIP E20.3
HI7190IPZ HI7190IPZ -40 to 85 20 Ld PDIP*
(Pb-free) E20.3
HI7190IB HI7190IB -40 to 85 20 Ld SOIC M20.3
HI7190IBZ
(Note) HI7190IBZ -40 to 85 20 Ld SOIC
(Pb-free) M20.3
HI7190IBZ-T
(Note) HI7190IBZ -40 to 85 20 Ld SOIC
Tape and Reel
(Pb-free)
M20.3
HI7190EVAL Evaluation Kit
*Pb-free PDIPs can be used for through hole wave solder
processing only. They are not intended for use in Reflow solder
processing applications.
NOTE: Intersil Pb-fre e plus anne al produc ts emp loy special Pb -free
material sets; molding compounds/die attach materials and 100%
matte tin plate termination finish, which are RoHS compliant and
compatible with both SnPb and Pb-free soldering operations. Intersil
Pb-free products are MSL classified at Pb-free peak reflow
temperatures that meet or exceed the Pb-free requirements of
IPC/JEDEC J STD-020.
∑DIGITAL FILTER
∑ − Δ
MODULATOR
PGIA
∑
1-BIT
D/A
1
CONTROL AND SERIAL INTERFACE UNIT
CONTROL REGISTER
SERIAL INTERFACE
UNIT
CLOCK
GENERATOR
AVDD
TRANSDUCER
BURN-OUT
CURRENT
VINHI
VINLO
VCM
OSC1OSC2DRDY RESET SYNC CS MODE SCLK SDIO SDO
VRHI VRLO
REFERENCE
INPUTS
∫∫
HI7190
3FN3612.10
June 27, 2006
Typical Application Schematic
10MHz
OSC1OSC2
VRHI
VRLO
+2.5V
AVDD
+5V
0.1μF
VCM
VINHI
VINLO
AGND
DVDD
DGND
SCLK
CS
DRDY
SYNC
SDO
SDIO
+5V
4.7μF
+
0.1μF
4.7μF
+
RESET
INPUT
INPUT
AVSS-5V
0.1μF
4.7μF
+
DATA I/O
DATA OUT
SYNC
CS
DRDY
RESET
13
17 16
15
12
11
10
9
8
7
14 6
18
5
4
19
2
3
1
MODE 20
REFERENCE
+
-
R1
HI7190
4FN3612.10
June 27, 2006
Absolute Maximum Ratings Thermal Information
Supply Voltage
AVDD to AGND. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +5.5V
AVSS to AGND. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -5.5V
DVDD to DGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +5.5V
DGND to AGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±0.3V
Analog Input Pins. . . . . . . . . . . . . . . . . . . . . . . . . . . . AVSS to AVDD
Digital Input, Output and I/O Pins . . . . . . . . . . . . . . DGND to DVDD
ESD Tolerance (No Damage)
Human Body Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .500V
Machine Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100V
Charged Device Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . .1000V
Operating Conditions
Temperature Range. . . . . . . . . . . . . . . . . . . . . . . . . . -40° C to 85°C
Thermal Resistance (Typical, Note 1) θJA (°C/W)
PDIP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Maximum Junction Temperature
Plastic Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150°C
Maximum Storage Temperature Range. . . . . . . . . . .-65°C to 150°C
Maximum Lead Temperature (Soldering, 10s). . . . . . . . . . . . .300°C
(SOIC - Lead Tips Only)
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTE:
1. θJA is measured with the component mounted on a low effective thermal conductivity test board in free air. See Tech Brief TB379 for details.
Electrical Specifications AVDD = +5V, AVSS = -5V, DVDD = +5V, VRHI = +2.5V, VRLO = AGND = 0V, VCM = AGND,
PGIA Gain = 1, OSCIN = 10MHz, Bipolar Input Range Selected, fN = 10Hz
PARAMET ER TEST CONDITIONS MIN TYP MAX UNITS
SYSTEM PERFORMANCE
Integral Non-Linearity, INL End Point Line Method (Notes 3, 5, 6) - ±0.0007 ±0.0015 %FS
Differential Non-Linearity (Note 2) No Missing codes to 22-Bits LSB
Offset Error, VOS See Table 1 - - - -
Offset Error Drift VINHI = VINLO (Notes 3, 8) - 1 - μV/°C
Full Scale Error, FSE VINHI - VINLO = +2.5V (Notes 3, 5, 8, 10) - - - -
Noise, eNSee Table 1 - - - -
Common Mode Re je ct io n Rat i o, CM RR VCM = 0V , VINHI = VINLO from -2V to +2V - 70 - dB
Normal Mode 50Hz Rejection Filter Notch = 10Hz, 25Hz, 50Hz (Note 2) 120 - - dB
Normal Mode 60Hz Rejection Filter Notch = 10Hz, 30Hz, 60Hz (Note 2) 120 - - dB
Step Response Settling Time - 2 4 Conversions
ANALOG INPUTS
Input Voltage Range Unipolar Mode (Note 9) 0 - VREF V
Input Voltage Range Bipolar Mode (Note 9) - VREF -V
REF V
Common Mode Input Range (Note 2) AVSS -AV
DD V
Input Leakage Current, IIN VIN = AVDD (Note 2) - - 1.0 nA
Input Capacitance, CIN -5.0- pF
Reference Voltage Range, VREF
(VREF = VRHI - VRLO)2.5 - 5 V
Transducer Burn-Out Current, IBO - 200 - nA
CALIBRATION LIMITS
Positive Full Scale Calibration Limit - - 1.2(VREF/Gain) -
Negative Full Scale Calibration Limit - - 1.2(VREF/Gain) -
Offset Calibration Limit - - 1.2(VREF/Gain) -
Input Span 0.2(VREF/Gain) - 2.4(VREF/Gain) -
DIGITAL INPUTS
Input Logic High Voltage, VIH (Note 11) 2.0 - - V
Input Logic Low Voltage, VIL --0.8 V
Input Logic Current, IIVIN = 0V, +5V - 1.0 10 μA
HI7190
5FN3612.10
June 27, 2006
Input Capacitance, CIN VIN = 0V - 5.0 - pF
DIGITAL OUTPUTS
Output Logic High Voltage, VOH IOUT = -100μA (Note 7) 2.4 - - V
Output Logic Low Voltage, VOL IOUT = 3mA (Note 7) - - 0.4 V
Output Three-State Leakage Current,
IOZ VOUT = 0V, +5V (Note 7) -10 1 10 μA
Digital Output Capacitance, COUT -10- pF
TIMING CHARACTERISTICS
SCLK Minimum Cycle Time, tSCLK 200 - - ns
SCLK Minimum Pulse Width, tSCLKPW 50 - - ns
CS to SCLK Precharge Time, tPRE 50 - - ns
DRDY Minimum High Pulse Width (Notes 2, 7) 500 - - ns
Data Setup to SCLK Rising Edge (Write),
tDSU 50 - - ns
Data Hold from SCLK Rising Edge
(Write), tDHLD 0-- ns
Data Read Access from Instruction Byte
Write, tACC (Note 7) - - 40 ns
Read Bit Valid from SCLK Falling Edge,
tDV (Note 7) - - 40 ns
Last Data Transfer to Data Ready
Inactive, tDRDY (Note 7) - 35 - ns
RESET Low Pulse Width (Note 2) 100 - - ns
SYNC Low Pulse Width (Note 2) 100 - - ns
Oscillator Clock Frequency (Note 2) 0.1 - 10 MHz
Output Rise/Fall Time (Note 2) - - 30 ns
Input Rise/Fall Time (Note 2) - - 1 μs
POWER SUPPLY CHARACTERISTICS
IAVDD --1.5mA
IAVSS --2.0mA
IDVDD SCLK = 4MHz - - 3.0 mA
Power Dissipation, Active PDASB = ‘0’ - 15 32.5 mW
Power Dissipation, Standby PDSSB = ‘1’ - 5 - mW
PSRR (Note 3) - -70 - dB
NOTES:
2. Parameter guaranteed by design or characterization, not production tested.
3. Applies to both bipolar and unipolar input ranges.
4. These errors can be removed by re-calibrating at the desired operating temperature.
5. Applies after system calibration.
6. Fully differential input signal source is used.
7. See Load Test Circuit, Figure 4, R1 = 10kΩ, CL = 50pF.
8. 1 LSB = 298nV at 24 bits for a Full Scale Range of 5V.
9. VREF = VRHI - VRLO.
10. These errors are on the order of the output noise shown in Table 1.
11. All inputs except OSC1. The OSC1 input VIH is 3.5V minimum.
Electrical Specifications AVDD = +5V, AVSS = -5V, DVDD = +5V, VRHI = +2.5V, VRLO = AGND = 0V, VCM = AGND,
PGIA Gain = 1, OSCIN = 10MHz, Bipolar Input Range Selected, fN = 10Hz (Continued)
PARAMET ER TEST CONDITIONS MIN TYP MAX UNITS
HI7190
6FN3612.10
June 27, 2006
Timing Diagrams
FIGURE 1. DATA WRITE TO HI7190
FIGURE 2. DATA READ FROM HI7190
FIGURE 3. DATA READ FROM HI7190
1ST BIT 2ND BIT
CS
SCLK
SDIO
tSCLK
tDSU
tDHLD
tSCLKPW tSCLKPW
tPRE
CS
SCLK
SDIO
SDO
tACC tDV
1ST BIT 2ND BIT
SCLK
CS
DRDY
SDIO
tDRDY
87651
HI7190
7FN3612.10
June 27, 2006
Pin Descriptions
20 LEAD
DIP, SOIC PIN NAME DESCRIPTION
1 SCLK Serial Interface Clock. Synchronizes serial data transfers. Data is input on the rising edge and output on the
falling edge.
2 SDO Serial Data OUT. Serial data is read from this line when using a 3-wire serial protocol such as the
Motorola Serial Peripheral Interface.
3 SDIO Serial Data IN or OUT. This line is bidirectional programmable and interfaces directly to the Intel Standard Serial
Interface using a 2-wire serial protocol.
4CS
Chip Select Input. Used to select the HI7190 for a serial data transfer cycle. This line can be tied to DGND.
5 DRDY An Active Low Interrupt indicating that a new data word is available for reading.
6 DGND Digital Supply Ground.
7AV
SS Negative Analog Power Supply (-5V).
8V
RLO External Reference Input. Should be negative referenced to VRHI.
9V
RHI External Reference Input. Should be positive referenced to VRLO.
10 VCM Common Mode Input. Should be set to halfway between AVDD and AVSS.
11 VINLO Analog Input LO. Negative input of the PGIA.
12 VINHI Analog Input HI. Positive input of the PGIA. The VINHI input is connected to a current source that can be used to check
the condition of an external tra nsducer. This current source is controlled via the Control Re gister.
13 AVDD Positive Analog Power Supply (+5V).
14 AGND Analog Supply Ground.
15 DVDD Positive Digital Supply (+5V).
16 OSC2Used to connect a crystal source between OSC1 and OSC2. Leave open otherwise.
17 OSC1Oscillator Clock Input for the device. A crystal connected between OSC1 and OSC2 will provide a clock to the device,
or an external oscillator can drive OSC1. The oscillator frequency should be 10MHz (Typ).
18 RESET Active Low Reset Pin. Used to initialize the HI7190 registers, filter and state machines.
19 SYNC Active Low Sync Input. Used to control the synchronization of a number of HI7190s. A log ic ‘0’ initializes the converter.
20 MODE Mode Pin. Used to select between Synchronous Self Clocking (Mode = 1) or Synchronous External Clocking
(Mode = 0) for the Serial Port.
Load Test Circuit
FIGURE 4.
V1
R1
CL (INCLUDES STRAY
DUT
CAPACITANCE)
ESD Test Circuits
FIGURE 5A. FIGURE 5B.
DUT
HUMAN BODY
CESD = 100pF
MACHINE MODEL
CESD = 200pF
R1
CESD
R1 = 10MΩ
R1 = 10MΩ
R2
R2 = 1.5kΩ
R2 = 0Ω
±
V
CHARGED DEVICE MODEL
R1
R1 = 1GΩ
R2R2 = 1Ω
±
V
DUT
DIELECTRIC
HI7190
8FN3612.10
June 27, 2006
TABLE 1. NOISE PERFORMANCE WITH INPUTS CONNECTED TO ANALOG GROUND
HERTZ SNR ENOB P-P NOISE
(μV) RMS NOISE
(μV)
GAIN = 1
10 132.3 21.7 9.8 1.5
25 129.5 21.2 13.6 2.1
30 127.7 20.9 16.6 2.5
50 126.3 20.7 19.5 3.0
60 125.6 20.6 21.2 3.2
100 122.4 20.0 30.7 4.6
250 107.7 17.6 166.7 25.3
500 98.1 16.0 505.3 76.6
1000 85.7 13.9 2101.8 318.5
2000 68.8 11.1 14661.6 2221.4
GAIN = 2
10 129.2 21.2 14.0 2.1
25 125.7 20.6 20.9 3.2
30 124.5 20.4 24.1 3.7
50 123.4 20.2 27.3 4.1
60 122.5 20.1 30.3 4.6
100 118.1 19.3 50.0 7.6
250 106.1 17.3 199.5 30.2
500 96.9 15.8 580.1 87.9
1000 84.4 13.7 2435.6 369.0
2000 67.8 11.0 16469.7 2495.4
GAIN = 4
10 125.9 20.6 20.5 3.1
25 123.1 20.1 28.4 4.3
30 121.8 19.9 32.8 5.0
50 119.9 19.6 40.9 6.2
60 119.9 19.6 40.9 6.2
100 116.1 19.0 63.2 9.6
250 105.7 17.3 209.7 31.8
500 96.6 15.8 597.8 90.6
1000 84.3 13.7 2469.5 374.2
2000 68.2 11.0 15656.1 2372.1
GAIN = 8
10 124.7 20.4 23.4 3.5
25 120.6 19.7 37.8 5.7
30 119.2 19.5 44.3 6.7
50 117.5 19.2 53.8 8.2
60 116.8 19.1 58.6 8.9
100 112.1 18.3 100.0 15.2
250 101.4 16.5 345.2 52.3
500 95.3 15.5 691.1 104.7
1000 83.1 13.5 2838.6 430.1
2000 68.3 11.1 15494.7 2347.7
GAIN = 16
10 120.1 19.7 39.8 6.0
25 114.8 18.8 73.4 11.1
30 113.5 18.6 85.1 12.9
50 111.0 18.1 114.4 17.3
60 109.6 17.9 134.0 20.3
100 105.5 17.2 214.8 32.5
250 95.2 15.5 699.1 105.9
500 89.1 14.5 1417.7 214.8
1000 83.5 13.6 2686.0 407.0
2000 62.6 10.1 30110.0 4562.1
GAIN = 32
10 113.2 18.5 88.8 13.5
25 109.0 17.8 142.7 21.6
30 108.2 17.7 157.4 23.8
50 104.7 17.1 235.8 35.7
60 105.0 17.1 227.8 34.5
100 102.3 16.7 310.5 47.0
250 93.4 15.2 861.1 130.5
500 87.1 14.2 1782.7 270.1
1000 78.2 12.7 4990.4 756.1
2000 57.0 9.2 57311.1 8683.5
GAIN = 64
10 106.7 17.4 186.2 28.2
25 102.9 16.8 288.4 43.7
30 101.9 16.6 325.8 49.4
50 98.5 16.1 479.8 72.7
60 98.9 16.1 459.8 69.7
100 96.3 15.7 620.2 94.0
250 85.5 13.9 2133.5 323.3
500 78.1 12.7 5025.0 761.4
1000 66.7 10.8 18693.5 2832.3
2000 50.5 8.1 120163.0 18206.5
GAIN = 128
10 101.1 16.5 356.5 54.0
25 96.0 15.7 638.3 96.7
30 95.2 15.5 704.8 106.8
50 93.2 15.2 882.2 133.7
60 92.2 15.0 996.7 151.0
100 91.4 14.9 1086.6 164.6
250 79.4 12.9 4346.4 658.5
500 71.8 11.6 10439.2 1581.7
1000 60.1 9.7 39923.0 6048.9
2000 44.8 7.1 233238.2 35339.1
HERTZ SNR ENOB P-P NOISE
(μV) RMS NOISE
(μV)
HI7190
9FN3612.10
June 27, 2006
Definitions
Integral Non-Linearity, INL, is the maximum deviation of
any digital code from a straight line passing through the
endpoints of the transfer function. The endpoints of the
transfer function are zero scale (a poin t 0.5 LSB belo w the
first code transition 000...000 and 000...001) and full scale (a
point 0.5 LSB above the last code transition 111...110 to
111...111).
Differential Non-Linearity, DNL, is the deviation fro m the
actual difference between midpoints and the ideal difference
between midpoints (1 LSB) for adjacent codes. If this
difference is equal to or more negative than 1 LSB, a code
will be missed.
Offset Error , VOS, is the deviation of the first code transition
from the ideal input voltage (VIN - 0.5 LSB). This error can
be calibrated to the order of the noise level shown in Table 1.
Full Scale Error, FSE, is the deviation of the last code
transition from the ideal input full scale voltage
(VIN-+V
REF/Gain - 1.5 LSB). This error can be calibrated
to the order of the noise level shown in Table 1.
Input Span, defines the minimum and maximum input
voltages the device can handle while still calibrating properly
for gain.
Noise, eN, Table 1 shows the pea k-to-peak and RMS noise
for typical notch and -3dB frequencies. The device
programming was for bipolar input with a VREF of +2.5V. This
implies the input range is 5V . The analysis was performed on
100 conversions with the peak-to-peak output noise being
the difference between the maximum and minimum readings
over a rolling 10 conversion window . The equation to convert
the peak-to-peak noise data to ENOB is:
ENOB = Log2 (VFS/VNRMS)
where: VFS = 5V, VNRMS = VNP-P/CF and
CF = 6.6 (Empirical Crest Factor)
The noise from the part comes from two sources, the
quantization noise from the analog-to-digital conversion
process and device noise. Device noise (or Wideband
Noise) is independent of gain and essen tially flat across the
frequency spectrum. Quantization noise is ratiometric to
input full scale (and hence gain) and its frequency response
is shaped by the modulator.
Looking at Table 1, as the cutoff frequency increases the
output noise increases. This is due to more of the
quantization noise of the part coming through to the output
and, hence, the output noise increases with increasing -3dB
frequencies. For the lower notch settings, the output noise is
dominated by the device noise and, hence, altering the gain
has little effect on the output noise. At higher notch
frequencies, the quantization noise dominates the output
noise and, in this case, the output noise tends to decrease
with increasing gain.
Since the output noise comes from two sources, the effective
resolution of the device (i.e., the ratio of the i nput full scale to
the output RMS noise) does not remain constant with
increasing gain or with increasing bandwidth. It is possible to
do post-filtering (such as brick wall filtering) on the data to
improve the overall resolution for a given -3dB frequency
and also to further reduce the output noise.
Circuit Description
The HI7190 is a monolithic, sigma delta A/D converter which
operates from ±5V supplies and is intended for
measurement of wide dynamic range, low frequency signals.
It contains a Programmable Gain Instrumentation Amplifier
(PGIA), sigma delta ADC, digital filter , bidirectional serial port
(compatible with many industry standard protocols), clock
oscillator, and an on-chi p controller.
The signal and reference inputs are fully differential for
maximum flexibility and performance. Normally VRHI and
VRLO are tied to +2.5V and AGND respectively. This allows
for input ranges of 2.5V and 5V when operating in the
unipolar and bipolar modes respectively (assuming the PGIA
is configured for a gain of 1). The internal PGIA provides
input gains from 1 to 128 and eliminates the need for
external pre-amplifiers. This means the device will convert
signals ranging from 0V to +20mV and 0V to +2.5V when
operating in the unipolar mode or signa ls in the range of
±20mV to ±2.5V when operating in the bipolar mode.
The input signal is continuously sampl ed at the input to the
HI7190 at a clock rate set by the oscillator frequency and the
selected gain. This signal then passes through the sigma
delta modulator (which includes the PGIA) and emerges as a
pulse train whose code density contains the analog signal
information. The output of the modulator is fed into the sinc3
digital low pass filter. The filter output passes into the
calibration block where offset and gain errors are removed.
The calibrated data is then coded (2’s complement, offset
binary or binary) before being stored in the Data Output
Register. The Data Output Register update rate is
determined by the first notch frequency of the digital filter.
This first notch frequency is programmed into HI7190 via the
Control Register and has a range of 10Hz to 1.953kHz which
corresponds to -3dB frequencies of 2.62Hz and 512H z
respectively.
Output data coding on the HI7190 is programmable via the
Control Register. When operating in bipolar mode, data
output can be either 2’s complement or offset binary. In
unipolar mode output is binary.
The DRDY signal is used to alert the user that new output
data is available. Converted data is read via the HI7190
serial I/O port which is compatible with most synchronous
transfer formats including both the Motorola 6805/11 series
HI7190
10 FN3612.10
June 27, 2006
SPI and Intel 8051 series SSR protocols. Data Integrity is
always maintained at the HI7190 output port. This means
that if a data read of conversion N is begun but not finished
before the next conversion (conversion N + 1) is complete,
the DRDY line remains active (low) and the data being read
is not overwritten.
The HI7190 provides many calibration mode s that can be
initiated at any time by writing to the Control Register. The
device can perform system calibration where external
components are included with the HI7190 in the calibration
loop or self-calibration where only the HI7190 itself is in the
calibration loop. The On-chip Calibration Registers are
read/write registers which allow the user to read calibratio n
coefficients as well as write previously determined
calibration coefficients.
Circuit Operation
The analog and digital supplies and grounds are separate
on the HI7190 to minimize digital noise coupling into the
analog circuitry. Nominal supply voltages are AVDD = +5V,
DVDD = +5V, and AVSS = -5V. If the same supply is used
for AVDD and DVDD it is imperative that the supply is
separately decoupled to the AVDD and DVDD pins on the
HI7190. Separate analog and digital ground planes should
be maint ained on the system board and the grounds shou ld
be tied together back at the power supply.
When the HI7190 is powered up it needs to be reset by
pulling the RESET line low. The reset sets the internal
registers of the HI7190 as shown in Table 2 and puts the part
in the bipolar mode with a gain of 1 and offset binary coding.
The filt er not ch of th e d igi tal filter is set at 30 Hz w hi le t he I/O
is set up for bidirectional I/O (data is read and written on the
SDIO line and SDO is three-stated), descending byte order,
and MSB first data format. A self calibration is performed
before the device begins converting. DRDY goes low when
valid data is availab l e at the output.
The configuration of the HI7190 is changed by writing new
setup data to the Control Register. Whenever data is written
to byte 2 and/or byte 1 of the Control Register the part
assumes that a critical setup parameter is be i n g ch an g ed
which means that DRDY goes high and the device is re-
synchronized. If the configuration is changed such that the
device is in any one of the cali bration mode s , a ne w
calibration is performed before normal conversions continue.
If the device is written to the conversion mode, a new
calibration is NOT performed (A new calibration is
recommended any time data is written to the Control
Register .). In either case, DRDY goes low when valid data is
available at the output.
If a single data byte is written to byte 0 of the Control
Register, the device assume s the gain has NOT been
changed. It is up to the user to re-calibrate the device if the
gain is changed in this manner. For this reason it is
recommended that the entire Control Register be written
when changing the gain of the device. This ensures that the
part is re-calibrated (if in a calibration mode) before th e
DRDY output goes low indicating that valid data is available.
The calibration registers can be read via th e serial interface
at any time. However, care must be taken when writing data
to the calibration registers. If the HI7190 is internally
updating any calibration register the user ca n not write to
that calibration register . See the Operational Modes section
for details on which calibration registers are updated for the
various modes.
Since access to the calibration registers is asynchronous to the
conversion process the user is cautioned that new calibration
data may not be used on the very next set of “valid” data after a
calibration register write. It is guaranteed that the new data will
take ef fect on the second set of output data. Non-calibrated
data can be obtained from the device by writing 000000 (h) to
the Offset Calibration Register, 800000 (h) to the Positive Full
Scale Calibration Register, and 800000 (h) to the Negative Full
Scale Calibration Register . This sets the of fset correction factor
to 0 and the positive and negative gain slope factors to 1.
If several HI7190s share a system master clock the SYNC
pin can be used to synchronize their operation. A common
SYNC input to multiple devices will synchronize operation
such that all output registers are updated simultaneously. Of
course the SYNC pin would normally be activated only after
each HI7190 has be en calibrated or has had calibration
coefficients written to it.
The SYNC pin can also be used to control the HI7190 when
an external multiplexer is used with a single HI7190. The
SYNC pin in this application can be used to guarantee a
maximum settling time of 3 conversion periods when
switching channels on the multiplexer.
Analog Section Description
Figure 6 shows a simplified block diagram of the analog
modulator front end of a sigma delta A/D Converter. The
input signal VIN comes into a summing junction (the PGIA in
this case) where the previous modulator output is subtracted
from it. The resulting signal is then integrated and the output
of the integrator goes into the comparat or. The output of the
comparator is then fed back via a 1-bit DAC to the summing
TABLE 2. REGISTER RESET VALUES
REGISTER VALUE (HEX)
Data Output Register XXXX (Undefined)
Control Register 28B300
Offset Calibration Register Self Calibration Value
Positive Full Scale Calibration Register Self Calibration Value
Negative Full Scale Calibration Register Self Calibration Value
HI7190
11 FN3612.10
June 27, 2006
junction. The feedback loop forces the average of the fed
back signal to be equal to the input signal VIN.
Analog Inputs
The analog input on the HI7190 is a fully differential input
with programmable gain capabilities. The input accepts both
unipolar and bipolar input signals and gains range from 1 to
128. The common mode range of this input is from AVSS to
AVDD provided that the absolute value of the analog input
voltage lies within the power supplies. The input impedance
of the HI7190 is dependent upon the modulator inpu t
sampling rate and the sampling rate varies with the selected
PGIA gain. Table 3 shows the sampling rates and input
impedances for the different gain settings of the HI7190.
Note that this table is valid only for a 10MHz master clock. If
the input clock frequency is changed, then the input
impedance will change accordingly. The equation used to
calculate the input impedance is:
where Cin is the nominal input capacitance (8pF) and fS is
the modulator sampling rate.
Bipolar/Unipolar Input Ranges
The input on the HI7190 can accept either unipolar or bipolar
input voltages. Bipolar or unipolar options are chosen by
programming th e B/U bit of the Control Register.
Programming the part for either unipolar or bipolar operation
does not change the input signal conditioning.
The inputs are differential, and as a result are referenced to the
volta ge on the VINLO in put. F or e xampl e, if VINLO is +1.25V
and the HI7190 is configured for unipolar operation with a gain
of 1 and a VREF of +2.5V, the input voltage range on the VINHI
input is +1.25V to +3.75V. If VINLO is +1.25V and the HI7190 is
configured for bipolar mode with gain of 1 and a VREF of +2.5V,
the analog input range on the VINHI input is -1.25V to +3.75V.
Programmable Gain Instrumentation Amplifier
The Programmable Gain Instrument ation Amplifier allows the
user to directly interface low level sensors and bridges directly
to the HI7190. The PGIA has 4 selectable g ain options of 1, 2,
4, 8 which are implemented by multiple sa mp ling of the input
signal. Input signals can be gained up further to 16, 32, 64 or
128. These higher gains are implemented in the digit al section
of the design to maintain a high signal to noise ratio through
the front end amplifiers. The gain is digit ally programmable in
the Control Register via the seri al interface. For optimum
PGIA performance the VCM pin should be tie d to the mid point
of the analog supplies.
Differential Reference Input
The reference inputs of the of the HI7190, VRHI and VRLO,
provide a differential reference input capability. The nominal
differential voltage (VREF = VRHI - VRLO) is +2.5V and the
common mode voltage cab be anywhere between A VSS and
AVDD. Larger values of VREF can be used without
degradation in performance with the maximum reference
voltage being VREF = +5V. Smaller values of VREF can also
be used but performance will be degraded since the LSB
size is reduced.
The full scale range of the HI7190 is defined as:
and VRHI must always be greater than VRLO for proper
operation of the device.
The reference inputs provide a high impedance dynamic
load similar to the analog inputs and the effective input
impedance for the reference in puts can be calcula te d in the
same manner as it is for the analog input impedance. The
only difference in the calculation is that CIN for the reference
inputs is 10.67pF. Therefore, the input impedance range for
the reference inputs is from 149kΩ in a gain of 8 or higher
mode to 833kΩ in the gain of 1 mode.
VCM Input
The voltage at the VCM input is the voltage that the internal
analog circuitry is referenced to and should always be tied to
the midpoint of the AVDD and AVSS supplies. This point
provides a common mode input voltage for the internal
operational amplifiers an d must be driven from a low noise,
low impedance source if it is not tied to analog ground.
Failure to do so will result in degraded HI7190 performance.
It is recommended that VCM be tied to analog ground when
operating off of AVDD = +5V and AVSS = -5V supplies.
VCM also determines the headroom at the upper and lower
ends of the power supplies which is limited by the common
mode input range where the internal operatio nal amplifiers
remain in the linear, high gain region of operation. The
HI7190 is designed to have a range of AVSS +1.8V < VCM <
TABLE 3. EFFECTIVE INPUT IMPEDANCE vs GAIN
GAIN SAMPLING RATE
(kHz) INPUT IMPEDANCE
(MΩ)
1 78.125 1.6
2 156.25 0.8
4 312.5 0.4
8, 16, 32, 64, 128 625 0.2
PGIA INTEGRATOR COMPARATOR
VRHI
VRLO
DAC
VIN +
-
∫
∑
+
-
FIGURE 6. SIMPLE MODULATOR BLOCK DIAGRAM
ZIN = 1/(CIN x fS),
FSRBIPOLAR = 2 x VREF/GAIN
FSRUNIPOLAR = VREF/GAIN
HI7190
12 FN3612.10
June 27, 2006
AVDD - 1.8V. Exceeding this range on the VCM pin will
compromise the device performance.
Transducer Burn-Out Current Source
The VINHI input of the HI7190 cont ai ns a 500nA (Typ) current
source which can be turned on/of f via the Contro l Register.
This current source can be used in checking whet her a
transducer has burnt-out or become open before attempting
to take measurement s on th at channel. Wh en the current
source is turned on an additional offset will be created
indicating the presence of a transducer. The current source is
controlled by the BO bit (Bit 4) in the Control Register and is
disabled on power up. See Fig ure 7 for an applicatio ns circuit.
Digital Section Description
A block diagram of the digital section of the HI7190 is shown
in Figure 8. This section includes a low pass decimation
filter, conversion controll er, calibration logic, serial interface,
and clock generator.
Digital Filtering
One advantage of digital filtering is that it occurs after the
conversion process and can remove noise introduced during
the conversion. It can not, however, remove noise present
on the analog signal prior to the ADC (which an anal og filter
can).
One problem with the modulator/digital filter combinatio n is
that excursions outside the full scale range of the device
could cause the modulator and digital filter to saturate. This
device has headroom built in to the modulator and digital
filter which tolerates signal deviations up to 33% outside of
the full scale range of the device. If noise spikes ca n dri v e
the input signal outside of this extended range, it is
recommended that an input analog filter is used or the
overall input signal level is reduced.
Low Pass Decimation Filter
The digital low-pass filter is a Hogenauer (sinc3) decimating
filter. This filter was ch osen because it is a cost effective low
pass decimating filter that minimizes the need for internal
multipliers and extensive storage and is most effective when
used with high sampling or oversampling rates. Figure 9
shows the frequency characteristics of the filter where fC is
the -3dB frequency of the input signal an d fN is the
programmed notch frequency. The analog modulator sends
a one bit data stream to the filter at a rate of that is
determined by:
fMODULATOR = fOSC/128
fMODULATOR = 78.125kHz for fOSC = 10MHz.
The filter then converts the serial modulator data into 40-bit
words for processing by the Hogenauer filter. The data is
decimated in the filter at a rate determined by the CODE
word FP10-FP0 (programed by the user into the Control
Register) and the external clock rate. The equation is:
fNOTCH = fOSC/(512 x CODE).
The Control Register has 11 bits that select the filter cutoff
frequency and the first notch of the filter. The output data
update rate is equal to the notch frequency. The notch
frequency sets the Nyquist sampling rate of the device while
the -3dB point of the filter determines the frequency
spectrum of interest (fS). The FP bits have a usable range of
10 through 2047 where 10 yields a 1.953kHz Nyquist rate.
The Hogenauer filter contains alias components that reflect
around the notch frequency. If the spectrum of the frequency
of interest reaches the alias component, the data has been
aliased and therefore undersampled.
Filter Characteristics
Please note: We have recently discovered a
performance anoma ly with the HI7190. The problem
occurs when the digital code for the notch filter is
programmed within certain frequencies. We believe the
error is caused by the calibration logic and the digital
notch code NOT the absolute fre q ue nc y. The error is
seen when the user applies mid-scale (0V input, Bipolar
mode). With this input, the expected digital output
VRHI
VRLO
VINHI
VINLO
AVDD
AVSS
CURRENT
SOURCE
HI7190
RATIOMETRIC
CONFIGURATION
LOAD CELL
FIGURE 7. BURN-OUT CURRENT SOURCE CIRCUIT
MODULATOR OUTPUT
SERIAL I/O SDO
SDIO
SCLK
CS
DRDY
RESETSYNC
OSC2
OSC1
MODULATOR
CLOCK
DIGITAL CALIBRATION
AND CONTROL
CLOCK
GENERATOR
FILTER
FIGURE 8. DIGITAL SECTION BLOCK DIAGRAM
HI7190
13 FN3612.10
June 27, 2006
should be mid-scale (800000h). Instead, there is a small
probability , of an erroneous negative full scale (000000h)
output. Refer to Technical Brief TB348 for complete
details.
The FP10 to FP0 bits programmed into the Control Register
determine the cutoff (or notch) frequency of the digital filter.
The allowable code range is 00AH. This corresponds to a
maximum and minimum cutoff frequency of 1.953kHz and
10Hz, respectively when operating at a clock frequency of
10MHz. If a 1MHz clock is used then the maximum and
minimum cutoff frequencies become 195.3kHz and 1Hz,
respectively. A plot of the (sinx/x)3 digital filter characteristics
is shown in Figure 9. This filte r provides greater than 120dB
of 50Hz or 60Hz rejection. Changing the clock frequency or
the programming of the FP bits does not change the shape
of the filter characteristics, it merely shifts the notch
frequency. Th is low pass digital filter at the output of the
converter has an accompanying settling time for step inputs
just as a low pass analog filter does. New data takes
between 3 and 4 conversion periods to settle and update on
the serial port with a conversion period tCONV being equal to
1/fN.
Input Filtering
The digital filter does not provide rejection at integer
multiples of the modulator sampling frequency. This implies
that there are frequency bands where noise passes to the
output without attenuation. For most cases this is not a
problem because the high oversampling rate and noise
shaping characteristics of the modulator cause this noise to
become a small portion of the broadband noise which is
filtered. However, if an anti-alias filter is necessary a single
pole RC filter is usually sufficient.
If an input filter is used the user must be careful that the source
impedance of the filter is low enough not to cause gain errors in
the system. The DC input impedance at the inputs is > 1GΩ but
it is a dynamic load that changes with clock frequency and
selected gain. The input sample rate, also dependent upon
clock frequency and gain, determines the allotted time for the
input capacitor to charge. The addition of external components
may cause the charge time of the capacitor to increase beyond
the allotted time. The result of the input not settling to the proper
value is a system gain error which can be eliminated by system
calibration of the HI7190.
Clocking/Oscillators
The master clock into the HI7190 can be supplied by either a
crystal connected between the OSC1 and OSC2 pins as
shown in Figure 10A or a CMOS compatible clock signal
connected to the OSC1 pin as shown in Figure 10B. The
input sampling frequency, modulator sampling frequency,
filter -3dB frequency, output update rate, and calibration time
are all directly related to the master clock fre quency, fOSC.
For example, if a 1MHz clock is used instead of a 10MHz
clock, what is normally a 10Hz conversion rate becomes a
1Hz conversion rate. Lowering the clock frequency will also
lower the amount of current drawn from the power supplies.
Please note that the HI7190 specifications are written for a
10MHz clock only.
Operational Modes
The HI7190 contains several operational modes including
calibration modes for cancelling offset and gain errors of
both internal and external circuitry. A calibration routine
should be initiated whenever there is a change in the
ambient operating temperature or supply voltage. Calibration
should also be initiated if there is a change in the gain, filter
notch, bipolar, or unipolar input range. Non-calibrated data
can be obtained from the device by writing 000000 to the
Offset Calibration Register, 800000 (h) to the Positive Full
Scale Calibration Register, and 800000 (h) to the Negative
Full Scale Calibration Register. This sets the offset
correction factor to 0 and both the positive and negative gain
slope factors to 1.
ALIAS BAND
fN ±fC
FREQUENCY (Hz)
AMPLITUDE (dB)
fN
fC2fN3fN4fN
0
-20
-40
-60
-80
-100
-120
FIGURE 9. LOW PASS FILTER FREQUENCY CHARACTERISTICS
FIGURE 10A.
FIGURE 10B.
FIGURE 10. OSCILLATOR CONFIGURATIONS
HI7190
OSC1OSC2
10MHz 1617
HI7190
OSC1OSC2
10MHz
1617
NO
CONNECTION
HI7190
14 FN3612.10
June 27, 2006
The HI7190 offers several different modes of Self-Calibration
and System Calibration. For calibration to occur, the on-chip
microcontroller must convert the modulator output for three
different input conditions - “zero-scale,” “positive full scale,”
and “negative full scale”. With these readings, the HI7190
can null any offset errors and calculate the gain slope factor
for the transfer function of the converter. It is imperative that
the zero-scale calibration be performed before either of the
gain calibrations. However, the order of the gain calibrations
is not important.
The calibration modes are user selectab le in the Control
Register by using the MD bits (MD2-MD0) as show n in
Table 4. DRDY will go low indicating that the calibration is
complete and there is valid data at the output.
Conversion Mode
For Conversion Mode operatio n the HI7190 converts the
differential voltage between VINHI and VINLO. From
switching into this mode it takes 3 conversion periods (3 x
1/fN) for DRDY to go low and new data to be va lid. No
calibration coefficients are generated when operating in
Conversion Mode as data is calibrated using the ex isting
calibration coefficients.
Self-Calibration Mode
Please note: Self-calibration is only valid when operating in a
gain of one. In addition, the offset and gain errors are not
reduced as with the full system calibration.
The Self-Calibration Mode is a three step process that
updates the Offset Calibration Register, the Positive Full
Scale Calibration Register, and the Negative Full Scale
Calibration Register. In th is mode an interna l offset
calibration is done by disconnecting the external inputs and
shorting the inputs of the PGIA together. After 3 conversion
periods the Offset Calibration Register is updated with the
value that corrects any internal offset errors.
After the offset calibration is completed, the Positive and
Negative Full Scale Calibration Registers are updated. The
inputs VINHI and VINLO are disconnected and the extern al
reference is applied across the modulator inputs. The
HI7190 then takes 3 conversion cycles to sample the data
and update the Positive Full Scale Calibration Register . Next
the polarity of the reference voltage across the modulator
input terminals is reversed and after 3 conversion cycles the
Negative Full Scale Calibration Register is updated. The
values stored in the Positive and Negative Full Scale
Calibration Registers correct for any internal gain errors in
the A/D transfer function. After 3 more conversion cycles the
DRDY line will activate signaling that the calibration is
complete and valid data is present in the Data Output
Register.
System Offset Calibration Mode
The System Offset Calibration Mode is a single step process
that allows the user to lump offset errors of external circuitry
and the internal errors of the HI7190 together and null them
out. This mode will convert the external differential signal
applied to the VIN inputs and then store that value in the
Offset Calibration Register. The user must apply the zero
point or offset voltage to the HI7190 analog inputs and allow
the signal to settle before selecting this mode. After 4
conversion periods the DRDY line will activate signaling that
the calibration is complete and valid data is present in the
Data Output Register.
System Positive Full Scale Calibration Mode
The System Positive Full Scale Calibratio n Mode is a single
step process that allows the user to lump gain errors of
external circuitry and the internal errors of the HI7190
together and null them out. This mode will convert the
external differential signal applied to the VIN inputs and
stores the converted value in the Positive Full Sca le
Calibration Register. The user must apply the +Full Scale
voltage to the HI7190 analog inputs and allow the signal to
settle before selecting this mode. After 4 conversion periods
the DRDY line will activate signaling th e calibration is
complete and valid data is present in the Data Output
Register.
System Negative Full Scale Calibration Mode
The System Negative Full Scale Calibration Mode is a
single-step process that allows the user to lump gain errors
of external circuitry and the internal errors of the HI7190
together and null them out. This mode will convert the
external differential signal applied to the VIN inputs and
stores the converted value in the Negative Full Scale
Calibration Register. The user must apply the -Full Scale
voltage to the HI7190 analog inputs and allow the signal to
settle before selecting this mode. After 4 conversion periods
the DRDY line will activate signaling th e calibration is
complete and valid data is present in the Data Output
Register.
TABLE 4. HI7190 OPERATIONAL MODES
MD2 MD1 MD0 OPERATIONAL MODE
0 0 0 Conversion
0 0 1 Self Calibration (Gain of 1 only)
0 1 0 System Offset Calibration
0 1 1 System Po sitiv e Fu ll Scale Calibration
1 0 0 System Negative Full Scale Calibration
1 0 1 System Offset/Internal Gain Calibration
(Gain of 1 only)
1 1 0 System Gain Calibration
111Reserved
HI7190
15 FN3612.10
June 27, 2006
System Offset/Interna l Gain Calibration Mode
Pl e a s e no t e : System Offset/Int ernal Gain is o n l y v a l i d wh e n
operating in a gain of one. In addition, the offset and gain errors
are not reduced as with the full system calibration.
The System Offset/Internal Gain Calibration Mode is a single
step process that updates the Offset Calibration Registe r,
the Positive Full Scale Calibration Register, and the
Negative Full Scale Calibration Register. First the external
differential signal applied to the VIN inputs is converted and
that value is stored in the Offset Calibration Register. The
user must apply the zero point or offset voltage to the
HI7190 analog inputs and allow the signal to settle before
selecting this mode.
After this is completed the Positive and Negative Full Scale
Calibration Registers are updated. The inputs VINHI and VINLO
are disconnected and the external reference is switched in. The
HI7190 then takes 3 conversion cycles to sample the data and
update the Positive Full Scale Calibration Register . Next the
polarity of the reference voltage across the VINHI and VINLO
terminals is reversed and after 3 conversion cycles the
Negative Full Calibration Register is updated. The values
stored in the Positive and Negative Full Scale Calibration
Registers correct for any internal gain errors in the A/D transfer
function. After 3 more conversion cycles, the DRDY line will
activate signaling that the calibration is complete and valid data
is present in the Data Output Register .
System Gain Calibration Mode
The Gain Calibration Mode is a single step process that
updates the Positive and Negative Ful l Scale Calibration
Registers. This mode will convert the external differential
signal applied to the VIN inputs and then stor e that value in
the Negative Full Scale Calibration Register. Then the
polarity of the input is reversed internally and another
conversion is performed. This conver sion result is written to
the Positive Full Scale Calibration Register. The user must
apply the +Full Scale voltage to the HI7190 analog inputs
and allow the signal to settle before selecting this mode.
After 1 more conversion period the DRDY line wil l activate
signaling the calibration is complete and valid data is present
in the data output register.
Reserved
This mode is not used in the HI7190 and should not be
selected. There is no internal detection logic to keep this
condition from being selected and care should be taken not
to assert this bit combination.
Offset and Span Limits
There are limits to the amount of offset and gain which can
be adjusted out for the HI7190. For both bipolar and unipolar
modes the minimum and maximum input spans are
0.2 x VREF/GAIN and 1.2 x VREF/GAIN respectively.
In the unipolar mode the offset plus the span cannot exceed
the 1.2 x VREF/GAIN limit. So, if the span is at its minimum
value of 0.2 x VREF/GAIN, the offset must be less than 1 x
VREF/GAIN. In bipolar mode the span is equidistant around
the voltage used for the zero scale point. For this mode the
offset plus half the span cannot exceed 1.2 x VREF/GAIN. If
the span is at ±0.2 x VREF/GAIN, then the offset can not be
greater than ±2 x VREF/GAIN.
Serial Interface
The HI7190 has a flexible, synchronous serial commu nication
port to allow easy interfacing to many in dustry st an dard
microcontrollers and microprocessors. The serial I/O is
compatible with most synchronous tran sfer format s, including
both the Motorola 6805/11 SPI and Intel 8051 SSR protocols.
The Serial Interface is a flexible 2-wire or 3-wire hardw are
interface where the HI7190 can be confi gured to read and
write on a single bidirectional l ine (SDIO) or configured for
writing on SDIO and reading on the SDO line.
The interface is byte organized with each registe r byte
having a specific address and single or mu ltiple byte
transfers are supported. In addition, the interface allows
flexibility as to the byte and bit access order . That is, the user
can specify MSB/LSB first bit positioning and can access
bytes in ascending/descending order from any byte position.
The serial interface allow s the user to co mmunicate with 5
registers that control the operation of the device.
Data Output Register - a 24-bit, read only register
containing the conversion results.
Control Register - a 24-bit, read/writ e register containing
the setup and operating modes of the device.
Offset Calibration Register - a 24-bit, read/write register
used for calibrating the zero point of the converter or system.
Positive Full Scale Calibration Register - a 24-bit,
read/write register used for calibrating the Positive Full Scale
point of the converter or system.
Negative Full Scale Calibration Register - a 24-bit,
read/write re gi ster used for calibra ti n g th e N eg a ti v e Ful l
Scale point of the converter or system.
Two clock modes are supported. The HI7190 can accept the
serial interface clock (SCLK) as an input from the system or
generate the SCLK signal as an output. If the MODE pin is
logic low the HI7190 is in external clocking mode and the
SCLK pin is configured as an input. In this mode the user
supplies the serial interface clock and all interface timing
specifications are synchronous to this input. If the MODE pin
is logic high the HI7190 is in self-clocking mode and the
SCLK pin is configured as an output. In self-clocking mode,
SCLK runs at FSCLK = OSC1/8 and stalls high at byte
boundaries. SCLK does NOT have the capability to stall low
in this mode. All interface timing specifications are
synchronous to the SCLK output.
Normal operation in self-clocking mode is as follows (See
Figure 12): CS is sampled low on falling OSC1 edges. The
HI7190
16 FN3612.10
June 27, 2006
first SCLK transition output is del ayed 29 OSC1 cycles from
the next rising OSC1. SCLK transitions eight times and then
stalls high for 28 OSC1 cycles. After this stall period is
completed SCLK will again transition eight times and stall
high. This sequence will repeat continuously while CS is
active.
The extra OSC1 cycle required when coming out of the CS
inactive state is a one clock cycle latency required to
properly sample the CS input. Note that the normal stall at
byte boundaries is 28 OSC1 cycles thus giving a SCLK rising
to rising edge stall period of 32 OSC1 cycles.
The affects of CS on the I/O are diff erent for self-clocking
mode (MODE = 1) than for external mode (MODE = 0). For
external clocking mode CS inactive disables the I/O state
machine, effectively freezing the state of the I/O cycle. That
is, an I/O cycle can be interrupted using chip select and the
HI7190 will continue with that I/O cycle when re-enabled via
CS. SCLK can continue toggling while CS is inactive. If CS
goes inactive during an I/O cycle, it is up to the user to
ensure that the state of SCLK is identical when reactivating
CS as to what it was when CS went inactive. For read
operations in external clocking mode, the output will go
three-state immediately upon deactivation of CS.
For self-clocking mode (MODE = 1), the affect s of CS are
differe nt. If CS transitions high (ina ctive) during the perio d
when data is being transferred (any non stall time) the HI7190
will complete the data tra nsfer to the byte boundary. That is,
once SCLK begins the eight tra nsition sequence, it will always
complete the eight cycles. If CS remains inactive after the byte
has been transferred it will be sampled a nd SCLK will remain
stalled high indefinitely. If CS has returned to active lo w before
the data byte transfer period is comp leted the H I7190 act s as
if CS was active during the entire transfer period.
It is important to realize that the user can in t errupt a dat a
transfer on byt e b ou n da ri e s. Th at is, if the Instruction
Register calls for a 3 byte transfer and CS is inactive after
only one byte has been transferred, the HI7190, when
reactivated, will continue with the remaining two bytes before
looking for the next Instruction Register write cycle.
Note that the outputs will NOT go three-state immediately upon
CS inactive for read operations in self-clocking mode. In the
case of CS going inactive during a read cycle the outputs
remain driving until after the last data bit is transferred. In the
case of CS inactive during the clock stall time it takes 1 OSC1
cycle plus prop delay (Max) for the output s to be disabled.
I/O Port Pin Descriptions
The serial I/O port is a bidirectional port which is used to
read the data register and read or write the control register
and calibration registers. The port contains two data lines, a
synchronous clock, and a status flag. Figure 11 shows a
diagram of the serial interface lines.
SDO - Serial Data out. Data is read from this line using those
protocols with separate lines for transmitting and receiving
data. An example of such a standard is the Motorola Serial
Peripheral Interface (SPI) using the 68HC05 and 68HC11
family of microcontroll ers , or other similar processors. In the
case of using bidirectional data transfer on SDIO, SDO does
not output data and is set in a high impedance state.
SDIO - Serial Data in or out. Data is always written to the
device on this line. However, this line can be used as a
bidirectional data line. This is done by properly setting up the
Control Register. Bidirectional data transfer on this line can
be used with Intel standard serial interfaces (SSR, Mode 0)
in MCS51 and MCS96 family of microcontrollers, or other
similar processors.
SCLK - Serial clock. The serial clock pin is used to
synchronize data to and from the HI7190 and to run the port
state m achines. In Synchronous External Clock Mode, SCLK
is configured as an input, is supplied by the user, and can
run up to a 5MHz rate. In Synchronous Self Clocking Mode,
SCLK is configured as an output and runs at OSC1/8.
CS - Chip select. This signal is an active low input that allows
more than one device on the same serial communication lines.
The SDO and SDIO will go to a high impedance state when this
signal is high. If driven high during any communication cycle,
that cycle will be suspended until CS reactivation. Chip select
can be tied low in systems that maintain control of SCLK.
CHIP SELECT
SDO
SDIO
SCLK
CS
DRDY
HI7190
DEVICE STATUS
BIDIRECTIONAL DATA
DATA OUT
PORT CLOCK
MODECLOCK MODE
FIGURE 11. HI7190 SERIAL INTERFACE
OSC1
CS
SCLK
29 33 37 41 45 89 121 125
FIGURE 12. SCLK OUTPUT IN SELF-CLOCKING MODE
HI7190
17 FN3612.10
June 27, 2006
DRDY - Data Ready. This is an output status flag from the
device to signal that the Data Output Register has been
updated with the new conversion result. DRDY is useful as an
edge or level sensitive interrupt signal to a microprocessor or
microcontroller . DRDY low indicates that new data is available
at the Data Output Register . DRDY will return high upon
completion o f a co mplete Dat a Ou tput R egister read cy cle.
MODE - Mode. This input is used to select betw een
Synchronous Self Clocking Mo de (‘1’) or the Synchronous
External Clocking Mode (‘0’). When this p in is tied to VDD the
serial port is configured in the Synchro nous Self Clocki ng
mode where the synchronous shif t clock (SCLK) for the serial
port is generated by the HI7190 an d has a frequency of
OSC1/8. When the pin is tie d to DGND the serial port i s
configured for the Synchronous Extern al Clocking Mode
where the synchronous shift cl ock for the serial port is
generated by an external device up to a maximum frequency
of 5MHz.
Programming the Serial Interface
It is useful to think of the HI7190 interface in terms of
communication cycles. Each communication cycle happens
in 2 phases. The first phase of every communication cycle
is the writing of an instruction byte. The second phase is
the data transfer as described by the instruction byte. It is
important to note that phase 2 of the communication cycle
can be a single byte or a multi-byte transfer of data. For
example, the 3-byte Data Output Register can be read
using one multi-byte commun ication cycle rather than thre e
single-byte communication cycles. It is up to the user to
maintain synchronism with respect to data transfers. If the
system processor “gets lost” the only way to r ecover is to
reset the HI7190. Figures 13A and 13B show bo th a 2-wire
and a 3-wire data transfer.
Several formats are available for reading from and writing to
the HI7190 registers in both the 2-wire and 3-wire protocols.
A portion of these formats is controlled by the CR<2:1> (BD
and MSB) bits which control the byte direction and bit or der
of a data transfer respectively. These two bits can be written
in any combination but only the two most useful will be
discussed here.
The first combination is to reset both the BD and MSB bits
(BD = 0, MSB = 0). This sets up the interface for descending
byte order and MSB first format. When this combination is
used the user should always write the Instruction Register
such that the starting byte is the most significant byte
address. For example, read three bytes of DR starting with
the most significant byte. The first byte read will be the most
significant in MSB to LSB format. The next byte will be the
next least significant (recall descending byte order) again in
MSB to LSB order. The last byte will be the next lesser
significant byte in MSB to LSB order. The entire word was
read MSB to LSB format.
The second combination is to set both the BD and MSB bits
to 1. This sets up the interface for ascending byte order and
LSB first format. When this combination is used the user
should always write the Instruction Register such that the
starting byte is the least significant byte address. For
example, read three bytes of DR starting with the least
significant byte. The first byte read will be the least
significant in LSB to MSB format. The next byte will be the
next greater significant (recall ascending byte order) again in
LSB to MSB order. The last byte will be the next greater
significant byte in LSB to MSB order. The entire word wa s
read MSB to LSB format.
After completion of each communication cycle, The HI7190
interface enters a standby mode while waiting to receive a
new instruction byte.
Instruction Byte Phase
The instruction byte phase initiates a data transfer
sequence. The processor writes an 8-bit byte (Instruction
Byte) to the Instruction Register . The instruction byte informs
the HI7190 about the Data transfer phase activities and
includes the follo wing information:
• Read or Write cycle
• Number of Bytes to be transferred
• Which register and starting byte to be accessed
Data Transfer Phase
In the data transfer phase, data transfer takes place as set
by the Instruction Register contents. See Write Operation
and Read Operation sections for detailed descriptions.
INSTRUCTION
BYTE DATA
BYTE 1 DATA
BYTE 2 DATA
BYTE 3
INSTRUCTION DATA TRANSFER
CYCLE
CS
SDIO
FIGURE 13A. 2-WIRE, 3-BYTE READ OR WRITE TRANSFER
INSTRUCTION
BYTE
DATA
BYTE 1 DATA
BYTE 2 DATA
BYTE 3
INSTRUCTION
DATA TRANSFER
CYCLE
CS
SDIO
SDO
FIGURE 13B. 3-WIRE, 3-BYTE READ TRANSFER
HI7190
18 FN3612.10
June 27, 2006
Instruction Register
The Instruction Register is an 8-bit register which is used
during a communications cycle for setting up read/write
operations.
R/W - Bit 7 of the Instruction Register determines whether a
read or write operation will be done fol lowing the instruction
byte load. 0 = READ, 1 = WRITE.
MB1, MB0 - Bits 6 and 5 of the Instruction Register
determine the number of bytes that will be accessed
following the instruction byte load. See Table 5 for the
number of bytes to transfer in the transfer cycle.
FSC - Bit 4 is used to determine whether a Positive Full Scale
Calibration Register I/O transfer (FSC = 0) or a Negative Full
Scale Calibration Register I/O transfer (FSC = 1) is bein g
performed (see Table 6).
A3, A2, A1, A0 - Bits 3 and 2 (A3 and A2) of the Instruction
Register determine which internal register will be accessed
while bits 1 and 0 (A1 and A0) determine which byte of that
register will be accessed first. See Table 6 for the address
decode.
Write Operation
Data can be written to the Control Register, Offset
Calibration Register , Positive Full Scale Calibration Register ,
and the Negative Full Scale Calibration Register. Write
operations are done using the SDIO, CS and SCLK lines
only, as all data is written into the HI7190 via the SDIO line
even when using the 3-wire configuration. Figures 14 and 15
show typical write timing diagrams.
The communication cycle is started by asserting the CS line
low and starting the clock from its idle state. To assert a write
cycle, during the instruction phase of the communication
cycle, the Instruction Byte should be set to a write transfer
(R/W = 1).
When writing to the serial port, data is latched into the
HI7190 on the rising edge of SCLK. Data can then be
changed on the falling edge of SCLK. Data can also be
changed on the rising edge of SCLK due to the 0ns hold time
required on the data. This is useful in pipelined applications
where the data is latched on the rising edge of the clock.
Read Operation - 3-Wire Transfer
Data can be read from the Data Output Register, Control
Register, Offset Calibration Re gister, Positive Full Scale
Calibration Register , and the Negative Full Scale Calibration
Register. When configured in 3-wire transfer mode, read
operations are done using the SDIO, SDO, CS and SCLK
lines. All data is read via the SDO line. Figures 16 and 17
show typical 3-wire read timing diagrams.
The communication cycle is started by asserting the CS line
and starting the clock from its idle state. To assert a read
cycle, during the instruction phase of the communication
cycle, the Instruction Byte should be set to a read transfer
(R/W = 0).
When reading the serial port, data is driven out of the HI7190
on the falling edge of SCLK. Data can be registered
externally on the next rising edge of SCLK.
Read Operation - 2-Wire Transfer
Data can be read from the Data Output Register, Control
Register, Offset Calibration Re gister, Positive Full Scale
Calibration Register , and the Negative Full Scale Calibration
Register. When configured in two-wire transfer mode, read
operations are done using the SDIO, CS and SCLK lines. All
data is read via the SDIO line. Figures 18 and 19 show
typical 2-wire read timing diagrams.
INSTRUCTION REGISTER
MSB654321LSB
R/W MB1 MB0 FSC A3 A2 A1 A0
TABLE 5. MULTIPLE BYTE ACCESS BITS
MB1 MB0 DESCRIPTION
00 Transfer 1 Byte
01 Transfer 2 Bytes
10 Transfer 3 Bytes
11 Transfer 4 Bytes
T ABLE 6. INTERNAL DA TA ACCESS DECODE ST ARTING
BYTE
FSCA3A2A1A0 DESCRIPTION
X 0000Data Output Register, Byte 0
X 0001Data Output Register, Byte 1
X 0010Data Output Register, Byte 2
X 0100Control Register, Byte 0
X 0101Control Register, Byte 1
X 0110Control Register, Byte 2
X 1000Offset Cal Register, Byte 0
X 1001Offset Cal Register, Byte 1
X 1010Offset Cal Register, Byte 2
0 1100Positive Full Scale Cal Register, Byte 0
0 1101Positive Full Scale Cal Register, Byte 1
0 1110Positive Full Scale Cal Register, Byte 2
1 1100Negative Full Scale Cal Register, Byte 0
1 1101Negative Full Scale Cal Register, Byte 1
1 1110Negative Full Scale Cal Register, Byte 2
TABLE 6. INTERNAL DA TA ACCESS DECODE STARTING
BYTE (Continued)
FSCA3A2A1A0 DESCRIPTION
HI7190
19 FN3612.10
June 27, 2006
The communication cycle is started by asserting the CS line
and starting the clock from its idle state. To assert a read cycle,
during the instruction phase of the communication cycle, the
Instruction Byte should be set to a read transfer (R/W = 0).
When reading the serial port, data is driven out of the HI7190
on the falling edge of SCLK. Data can be registered
externally on the next rising edge of SCLK.
Detailed Register Descriptions
Data Output Regist er
The Data Output Register contains 24 bits of converted data.
This register is a read only register.
BYTE 2
MSB22212019181716
D23 D22 D21 D20 D19 D18 D17 D16
BYTE 1
15 14 13 12 11 10 9 8
D15 D14 D13 D12 D11 D10 D9 D8
BYTE 0
7654321LSB
D7 D6 D5 D4 D3 D2 D1 D0
IR WRITE PHASE DATA TRANSFER PHASE - TWO-BYTE WRITE
CS
SCLK
SDIO
SDO THREE-STATETHREE-STATE
I0 I1 I2 I3 I4 I5 I6 I7 B0 B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12 B13 B14 B15
FIGURE 14. DATA WRITE CYCLE, SCLK IDLE LOW
IR WRITE PHASE DATA TRANSFER PHASE - TWO-BYTE WRITE
CS
SCLK
S
DIO
SDO
I0 I1 I2 I3 I4 I5 I6 I7 B0 B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12 B13 B14
B15
THREE-STATE THREE-STATE
FIGURE 15. DATA WRITE CYCLE, SCLK IDLE HIGH
DATA TRANSFER PHASE - TWO-BYTE READ
CS
SCLK
SDIO
SDO
I0 I1 I2 I3 I4 I5 I6 I7
B0 B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12 B13 B14
B15
IR WRITE PHASE
FIGURE 16. DATA READ CYCLE, 3-WIRE CONFIGURATION, SCLK IDLE LOW
HI7190
20 FN3612.10
June 27, 2006
Control Register
The Control Register contains 24-bits to control the various
sections of the HI7190. This register is a read/write
register.
DC - Bit 23 is the Data Coding Bit used to select between
two’s complementary and offset binary data coding. When
this bit is set (DC = 1) the data in the Data Output Register
will be two’s complement. When cleared (DC = 0) this data
will be offset binary. When operating in the unipolar mode
the output data is available in straight binary only (the DC bit
is ignored). This bit is cleared after a RESET is applied to the
part.
FP10 through FP0 - Bits 22 through 12 are the Filter
programming bits that determine the frequency response of
the digital filter. These bits determine the filter cutoff
frequency, the position of the first notch and the data rate of
the HI7190. The first notch of the filter is equal to the
decimation rate and can be determined by the formula:
fNOTCH = fOSC /(512 x CODE)
where CODE is the decimal equivalent of the value in FP10
through FP0. The values that can be programmed into these
bits are 10 to 2047 decimal, which allows a conversion rate
range of 9.54Hz to 1.953kHz when using a 10MHz clock.
IR WRITE PHASE DATA TRANSFER PHASE - TWO-BYTE READ
CS
SCLK
SDIO
SDO
I0 I1 I2 I3 I4 I5 I6 I7
B0 B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12 B13 B14
B15
FIGURE 17. DATA READ CYCLE, 3-WIRE CONFIGURATION, SCLK IDLE HIGH
THREE-STATETHREE-STATE
IR WRITE PHASE DATA TRANSFER PHASE - TWO-BYTE READ
CS
SCLK
SDIO
SDO
I0 I1 I2 I3 I4 I5 I6 I7 B0 B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12 B13 B14
B15
FIGURE 18. DATA READ CYCLE, 2-WIRE CONFIGURATION, SCLK IDLE LOW
THREE-STATETHREE-STATE
IR WRITE PHASE DAT A TRANSFER PHASE - TWO-BYTE READ
CS
SCLK
SDIO
SDO
I0 I1 I2 I3 I4 I5 I6 I7 B0 B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12 B13 B14
B15
FIGURE 19. DATA READ CYCLE, 2-WIRE CONFIGURATION, SCLK IDLE HIGH
BYTE 2
MSB22212019181716
DC FP10 FP9 FP8 FP7 FP6 FP5 FP4
BYTE 1
15 14 13 12 11 10 9 8
FP3 FP2 FP1 FP0 MD2 MD1 MD0 B/U
BYTE 0
7654321LSB
G2 G1 G0 BO SB BD MSB SDL
HI7190
21 FN3612.10
June 27, 2006
Changing the filter notch frequency, as well as the selected
gain, impacts resolution. The output data rate (or effective
conversion time) for the device is equal to the frequency
selected for the first notch to the filter. For example, if the
first notch of the filter is selected at 50Hz then a new word is
available at a 50Hz rate or every 20ms. If the first notch is at
1kHz a new word is available every 1ms.
The settling-time of the converte r to a full scale step input
change is between 3 and 4 times the data rate. For example,
with the first filter notch at 50Hz, th e wo rst cas e set tling time
to a full scale step input change is 80ms. If the first notch is
1kHz, the settling time to a full scale input step is 4ms
maximum.
The -3dB frequency is determined by the programmed first
notch frequency according to the relationship:
f -3dB = 0.262 x fNOTCH.
MD2 through MD0 - Bits 11 through 9 are the Operational
Modes of the converter. See Table 4 for the Operational
Modes description. After a RESET is applied to the part
these bits are set to the self calibration mode.
B/U - Bit 8 is the Bipolar/Unipolar select bit. When this bit is
set the HI7190 is configured for bipolar operation. When this
bit is reset the part is in unipolar mode. This bit is set after a
RESET is applied to the part.
G2 through G0 - Bits 7 through 5 select the gain of the input
analog signal. The gain is accomplished through a
programmable gain instrumentation amplifier that gains up
incoming signals from 1 to 8. Th is is ach ieved by using a
switched capacitor voltage multiplier network preceding the
modulator. The higher gains (i.e., 16 to 128) are achieved
through a combination of a PGIA gai n of 8 and a digital
multiply after the digital filter (see Table 7). The gain will
affect noise and Signal to Noise Ratio of the conversion.
These bits are cleared to a gain of 1 (G2, G1, G0 = 000) after
a RESET is applied to the part.
BO - Bit 4 is the T ransducer Burn-Out Current source enable
bit. When this bit is set (BO = 1) the burn-out current source
connected to VINHI internally is enabled. This current source
can be used to detect the presence of an extern al
connection to VINHI. This bit is cleared after a RESET is
applied to the part.
SB - Bit 3 is the Standby Mode enable bit used to put the
HI7190 in a lower power/standby mode. When this bit is set
(SB = 1) the filter nodes are halted, the DRDY line is set high
and the modulator clock is disabled. When this bit is cleared
the HI7190 begins operation as described by the contents of
the Control Register. For example, if the Control Register is
programmed for Self Cal ibration Mode and a notch
frequency to 10Hz, the HI7190 will perform the self
calibration before providing the data at the 10Hz rate. This
bit is cleared after a RESET is applied to the part.
BD - Bit 2 is the Byte Direction bit used to select the mul ti -
byte access ordering. The bit determines the either
ascending or descending order access for the multi-byte
registers. When set (BD = 1) the user can access multi-byte
registers in ascending byte order and when cleared (BD = 0)
the multi-byte registers are accessed in descending byte
order. This bit is cleared after a RESET is applied to the part.
MSB - Bit 1 is used to select whether a serial data transfer is
MSB or LSB first. This bit allows the user to change the
order that data can be transmitted or received by the
HI7190. When this bit is cleared (MSB = 0) the MSB is the
first bit in a serial data transfer. If set (MSB = 1), the LSB is
the first bit transferred in the serial data stream. This bit is
cleared after a RESET is applied to the part.
SDL - Bit 0 is the Serial Data Line control bit. This bit selects
the transfer protocol of the serial interface. When this bit is
cleared (SDL = 0), both read and write data transfers are
done using the SDIO line. When set (SDL = 1), write
transfers are done on the SDIO line and read transfers are
done on the SDO line. This bit is cleared after a RESET is
applied to the part.
Reading the Data Output Register
The HI7190 generates an active low interrupt (DRDY)
indicating valid conversion results are available for reading.
At this time the Data Output Register contains the latest
conversion result available from the HI7190. Data integrity is
maintained at the serial output port but it is possible to miss
a conversion result if the Data Output Register is not read
within a given period of time. Maintaining data integrity
means that if a Data Output Register read of conversion N is
begun but not finished before the next conversion
(conversion N + 1) is complete, the DRDY line remains
active low and the data being read is not overwritten.
In addition to the Data Output Register, the HI7190 has a
one conversion result storage buffer. No conversion results
will be lost if the following constraints are met.
1) A Data Output Register read cycle is started for a given
conversion (conversion X) 1/fN - (128*1/fOSC) after DRDY
initially goes active low. Failure to start the read cycle may
TABLE 7. GAIN SELECT BITS
G2 G1 G0 GAIN GAIN ACHIEVED
0 0 0 1 PGIA = 1, Filter Multiply = 1
0 0 1 2 PGIA = 2, Filter Multiply = 1
0 1 0 4 PGIA = 4, Filter Multiply = 1
0 1 1 8 PGIA = 8, Filter Multiply = 1
1 0 0 16 PGIA = 8, Filter Multiply = 2
1 0 1 32 PGIA = 8, Filter Multiply = 4
1 1 0 64 PGIA = 8, Filter Multiply = 8
1 1 1 128 PGIA = 8, Filter Multiply = 16
HI7190
22 FN3612.10
June 27, 2006
result in conversion X + 1 data overwriting conversion X
results. For example, with fOSC = 10MHz, fN = 2kHz, the
read cycle must start within 1/2000 - 128(1/106) = 487μs
after DRDY went low.
2) The Data Output Register read cycle for conversion X
must be completed within 2(1/fN)-1440(1/fOSC) after DRDY
initially goes active low. If the read cycle for conversion X is
not complete within this time the results of conversion X + 1
are lost and results from conversion X + 2 are now stored in
the data output word buffer.
Completing the Data Output Register read cycle inactivates
the DRDY interrupt. If the one word data output buffer is full
when this read is complete this data will be immediately
transferred to the Data Output Register and a new DRDY
interrupt will be issued after the minimum DRDY pulse high
time is met.
Writing the Control Register
If data is written to byte 2 and/or byte 1 of the Control
Register the DRDY output is taken high and the device re-
calibrates if written to a calibration mode. This action is taken
because it is assumed that by writing byte 2 or byte 1 that
the user either reprogrammed the filter or changed modes of
the part. However, if a single data byte is written to byte 0, it
is assumed that the gain has NOT been changed. It is up to
the user to re-calibrate the HI7190 after the gain has been
changed by this method. It is recommended that the entire
Control Register be written to when changing the selected
gain. This ensures that the part is re-calibrated before the
DRDY signal goes low indi cating valid data is available.
Offset Calibration Register
The Offset Calibration Register is a 24-bit register containing
the offset correction factor. This register is indeterminate on
power-up but will contain a Self Calibration correction value
after a RESET has been applied.
The Offset Calibration Register holds the value that corrects
the filter ou tput dat a to al l 0’s when the analog in p ut is 0V.
Positive Full Scale Calibration Register
The Positive Full Scale Calibration Regi ster is a 24-bit
register containing the Positive Full Scale correction
coefficient. This coefficient is used to determine the positive
gain slope factor . This register is indeterminate on power-up
but will contain a Self Calibration correction coefficient after
a RESET has been applied.
Negative Full Scale Calibration Register
The Negative Full Scale Calibration Register is a 24-bit
register containing the Negative Full Scale correction
coefficient. This coefficient is used to determine the negative
gain slope factor . This register is indeterminate on power-up
but will contain a Self Calibration correction coefficient after
a RESET has been applied.
BYTE 2
MSB22212019181716
O23 O22 O21 O20 O19 O18 O17 O16
BYTE 1
15 14 13 12 11 10 9 8
O15 O14 O13 O12 O11 O10 O9 O8
BYTE 0
7654321LSB
O7 O6 O5 O4 O3 O2 O1 O0
BYTE 2
MSB22212019181716
P23P22P21P20P19P18P17P16
BYTE 1
15 14 13 12 11 10 9 8
P15 P14 P13 P12 P11 P10 P9 P8
BYTE 0
7654321LSB
P7 P6 P5 P4 P3 P2 P1 P0
BYTE 2
MSB22212019181716
N23 N22 N21 N20 N19 N18 N17 N16
BYTE 1
15 14 13 12 11 10 9 8
N15 N14 N13 N12 N11 N10 N9 N8
BYTE 0
7654321LSB
N7 N6 N5 N4 N3 N2 N1 N0
HI7190
23 FN3612.10
June 27, 2006
Die Characteristics
DIE DIMENSIONS
3550μm x 6340μm
METALLIZATION
Type: AlSiCu
Thickness:Metal 2, 16kÅ
Metal 1, 6kÅ
SUBSTRATE POTENTIAL (POWERED UP)
AVSS
PASSIVATION
Type: Sandwich
Thickness:Nitride 8kÅ
USG 1kÅ
Metallization Mask Layout HI7190
SCLK
SDO
SDIO
CS
DRDY
DGND
AVSS
VRLO
VRHI
VCM
VINLO
VINHI
AVDD
MODE
SYNC
RESET
AGND
DVDD
OSC2
OSC1
HI7190
24 FN3612.10
June 27, 2006
HI7190
Dual-In-Line Plastic Packages (PDIP)
NOTES:
1. Controlling Dimensions: INCH. In case of conflict between English
and Metric dimensions, the inch dimensions control.
2. Dimensioning and tolerancing per ANSI Y14.5M-1982.
3. Symbols are defined in the “MO Series Symbol List” in Section 2.2
of Publication No. 95.
4. Dimensions A, A1 and L are measured with the package seated in
JEDEC seating plane gauge GS-3.
5. D, D1, and E1 dimensions do not include mold flash or protrusions.
Mold flash or protrusions shall not exceed 0.010 inch (0.25mm).
6. E and are measured with the leads constrained to be perpen-
dicular to datum .
7. eB and eC are measured at the lead tips with the leads uncon-
strained. eC must be zero or greater.
8. B1 maximum dimensions do not include dambar protrusions. Dam-
bar protrusions shall not exceed 0.010 inch (0.25mm).
9. N is the maximum number of terminal positions.
10. Corner leads (1, N, N/2 and N/2 + 1) for E8.3, E16.3, E18.3, E28.3,
E42.6 will have a B1 dimension of 0.030 - 0.045 inch (0.76 - 1.14mm).
eA
-C-
C
L
E
eA
C
eB
eC
-B-
E1
INDEX 12 3 N/2
N
AREA
SEATING
BASE
PLANE
PLANE
-C-
D1
B1 Be
D
D1
A
A2
L
A1
-A-
0.010 (0.25) C AMBS
E20.3 (JEDEC MS-001-AD ISSUE D)
20 LEAD DUAL-IN-LINE PLASTIC PACKAGE
SYMBOL
INCHES MILLIMETERS
NOTESMIN MAX MIN MAX
A-0.210 -5.33 4
A1 0.015 -0.39 -4
A2 0.115 0.195 2.93 4.95 -
B0.014 0.022 0.356 0.558 -
B1 0.045 0.070 1.55 1.77 8
C0.008 0.014 0.204 0.355 -
D0.980 1.060 24.89 26.9 5
D1 0.005 -0.13 -5
E0.300 0.325 7.62 8.25 6
E1 0.240 0.280 6.10 7.11 5
e 0.100 BSC 2.54 BSC -
eA0.300 BSC 7.62 BSC 6
eB-0.430 -10.92 7
L0.115 0.150 2.93 3.81 4
N20 209
Rev. 0 12/93
25
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Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No lice nse is gran t ed by i mpli catio n or other wise u nder an y p a tent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see www.intersil.com
FN3612.10
June 27, 2006
HI7190
Small Outline Plastic Packages (SOIC)
NOTES:
1. Symbols are defined in the “MO Series Symbol List” in Section
2.2 of Publication Number 95.
2. Dimensioning and tolerancing per ANSI Y14.5M-1982.
3. Dimension “D” does not include mold flash, protrusions or gate
burrs. Mold flash, protrusion and gate burrs shall not exceed
0.15mm (0.006 inch) per side.
4. Dimension “E” does not include interlead flash or protrusions.
Interlead flash and protrusions shall not exceed 0.25mm (0.010
inch) per side.
5. The chamfer on the body is optional. If it is not present, a visual
index feature must be located within the crosshatched area.
6. “L” is the length of terminal for soldering to a substrate.
7. “N” is the number of terminal positions.
8. Terminal numbers are shown for reference only.
9. The lead width “B”, as measured 0.36mm (0.014 inch) or greater
above the seating plane, shall not exceed a maximum value of
0.61mm (0.024 inch)
10. Controlling dimension: MILLIMETER. Converted inch
dimensions are not necessarily exact.
INDEX
AREA E
D
N
123
-B-
0.25(0.010) C A
MBS
e
-A-
L
B
M
-C-
A1
A
SEATING PLANE
0.10(0.004)
h x 45°
C
H0.25(0.010) B
MM
α
M20.3 (JEDEC MS-013-AC ISSUE C)
20 LEAD WIDE BODY SMALL OUTLINE PLASTIC PACKAGE
SYMBOL
INCHES MILLIMETERS
NOTESMIN MAX MIN MAX
A 0.0926 0.1043 2.35 2.65 -
A1 0.0040 0.0118 0.10 0.30 -
B 0.014 0.019 0.35 0.49 9
C 0.0091 0.0125 0.23 0.32 -
D 0.4961 0.5118 12.60 13.00 3
E 0.2914 0.2992 7.40 7.60 4
e 0.050 BSC 1.27 BSC -
H 0.394 0.419 10.00 10.65 -
h 0.010 0.029 0.25 0.75 5
L 0.016 0.050 0.40 1.27 6
N20 207
α0° 8° 0° 8° -
Rev. 2 6/05
