AS5043 Programmable 360° Magnetic Angle Encoder
Revision 1.6, 3-Oct-06 www.austriamicrosystems.com Page 1 of 26
1 General Description
The AS5043 is a contactless magnetic angle encoder for accurate
measurement up to 360°.
It is a system-on-chip, combining integrated Hall elements,
analog front end and digital signal processing in a single device.
The AS5043 provides a digital 10-bit as well as a programmable
analog output that is directly proportional to the angle of a
magnet, rotating over the chip.
The analog output can be configured in many ways, including
user programmable angular range, adjustable output voltage
range, voltage or current output, etc..
An internal voltage regulator allows operation of the AS5043 from
3.3V or 5.0V supplies.
Figure 1: Typical arrangement of AS5043 and magnet
2 Benefits
Complete system-on-chip
- Flexible system solution provides absolute output, both digital
and analog
- Angle measurement with software programmable range up to
360°
- High reliability due to non-contact magnetic sensing
- Ideal for applications in harsh environments
- Robust system, tolerant to magnet misalignment, airgap
variations, temperature variations and external magnetic fields
- No calibration required
3 Key Features
360° contactless high resolution angular position encoding
User programmable zero position
Two 10-bit absolute outputs:
Serial digital interface and
Versatile analog output
programmable angular range up to 360°
programmable ratiometric output voltage range
Failure detection mode for magnet field strength and loss of
power supply
Serial read-out of multiple interconnected AS5043 devices
using daisy chain mode
Mode input for optimizing noise vs. speed
Alignment mode for magnet placement guidance
Wide temperature range: - 40°C to + 125°C
Small package: SSOP 16 (5.3mm x 6.2mm)
4 Applications
The AS5043 is ideal for applications with an angular
travel range from a few degrees up to a full turn of
360°, such as
- Industrial applications:
- Contactless rotary position sensing
- Robotics
- Valve Controls
- Automotive applications:
- Throttle position sensors
- Gas / brake pedal position sensing
- Headlight position control
Front panel rotary switches
Replacement of potentiometers
DATA SHEET
AS5043
PROGRAMMABLE 360° MAGNETIC ANGLE ENCODER
WITH ABSOLUTE SSI AND ANALOG OUTPUTS
PRELIMINARY DATA SHEET
AS5043 Programmable 360° Magnetic Angle Encoder
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5 Pin Configuration
AS5043
Figure 2: AS5043 pin configuration SSOP16
Package = SSOP16 (16 lead Shrink Small Outline Package)
Pin Symbol Type Description
1 MagRngn DO_OD
Magnet Field Magnitude RaNGe warning;
active low, indicates that the magnetic
field strength is outside of the
recommended limits.
2 Mode DI_PD,
ST
Mode input. Select between low noise
(open, low) and high speed (high) mode.
Internal pull-down resistor
3 CSn DI_PU,
ST
Chip Select, active low; Schmitt-Trigger
input, internal pull-up resistor (~50kΩ)
4 CLK DI,ST Clock Input of Synchronous Serial
Interface; Schmitt-Trigger input
5 NC - must be left unconnected
6 DO DO_T
Data Output of Synchronous Serial
Interface
7 VSS S Negative Supply Voltage (GND)
8 Prog_DI DI_PD
OTP Programming Input and Data Input
for Daisy Chain mode. Internal pull-down
resistor (~74kΩ).
Should be connected to VSS if
programming is not used
9 DACref AI DAC Reference voltage input for external
reference
10 DACout AO DAC output (unbuffered, Ri ~8kΩ)
11 FB AI Feedback, OPAMP inverting input
12 Vout AO OPAMP output
13 NC - Must be left unconnected
14 NC - Must be left unconnected
15 VDD3V3 S
3V-Regulator Output for internal core,
regulated from VDD5V.Connect to
VDD5V for 3V supply voltage. Do not
load externally.
16 VDD5V S Positive Supply Voltage, 3.0 to 5.5 V
Table 1: Pin description SSOP16
DO_OD digital output open drain S supply pin
DI_PD digital input pull-down DO_T digital output /tri-state
DI_PU digital input pull-up ST schmitt-trigger input
AI analog input AO analog output
DI digital input
5.1 Pin Description
Pins 7, 15 and 16 are supply pins, pins 5, 13 and 14
are for internal use and must be left open.
Pin 1 is the magnetic field strength indicator,
MagRNGn. It is an open-drain output that is pulled to
VSS when the magnetic field is out of the
recommended range (45mT to 75mT). The chip will
still continue to operate, but with reduced
performance, when the magnetic field is out of range.
When this pin is low, the analog output at pins #10
and #12 will be 0V to indicate the out-of-range
condition.
Pin 2 MODE allows switching between filtered (slow)
and unfiltered (fast mode). See section 9.
Pin 3 Chip Select (CSn; active low) selects a device
for serial data transmission over the SSI interface. A
“logic high” at CSn forces output DO to digital tri-
state.
Pin 4 CLK is the clock input for serial data
transmission over the SSI interface (see section 8)
Pin 6 DO (Data Out) is the serial data output during
data transmission over the SSI interface (see section
8)
Pin 8 PROG_DI is used to program the different
operation modes, as well as the zero-position in the
OTP register.
This pin is also used as a digital input to shift serial
data through the device in Daisy Chain Configuration,
(see page 6).
Pin 9 DACref is the external voltage reference input
for the Digital-to-Analog Converter (DAC). If selected,
the analog output voltage on pin 12 (Vout) will be
ratiometric to the voltage on this pin.
Pin10 DACout is the unbuffered output of the DAC.
This pin may be used to connect an external OPAMP,
etc. to the DAC.
Pin 11 FB (Feedback) is the inverting input of the
OPAMP buffer stage.
Access to this pin allows various OPAMP
configurations.
AS5043 Programmable 360° Magnetic Angle Encoder
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Pin 12 Vout is the analog output pin. The analog output is a DC
voltage, ratiometric to VDD5V (3.0 – 5.5V) or an external voltage
source and proportional to the angle.
6 Functional Description
The AS5043 is manufactured in a CMOS standard process and
uses a spinning current Hall technology for sensing the magnetic
field distribution across the surface of the chip.
The integrated Hall elements are placed in a circle around the
center of the device and deliver a voltage representation of the
magnetic field perpendicular to the surface of the IC.
Through Sigma-Delta Analog / Digital Conversion and Digital
Signal-Processing (DSP) algorithms, the AS5043 provides
accurate high-resolution absolute angular position information.
For this purpose a Coordinate Rotation Digital Computer
(CORDIC) calculates the angle and the magnitude of the Hall
array signals.
The DSP is also used indicate movements of the magnet towards
or away from the chip and to indicate, when the magnetic field is
outside of the recommended range (status bits = MagInc,
MagDec; hardware pin = MagRngn).
A small low cost diametrically magnetized (two-pole) standard
magnet, centered over the chip, is used as the input device.
The AS5043 senses the orientation of the magnetic field and
calculates a 10-bit binary code. This code can be accessed via a
Synchronous Serial Interface (SSI). In addition, the absolute
angular representation is converted to an analog
signal, ratiometric to the supply voltage.
The analog output can be configured in many ways,
such as 360°/180°/90° or 45° angular range, external
or internal DAC reference voltage, 0-100%*VDD or 10-
90% *VDD analog output range, external or internal
amplifier gain setting.
The various output modes as well as a user
programmable zero position can be programmed in an
OTP register. As long as no programming voltage is
applied to pin PROG, the new setting may be
overwritten at any time and will be reset to default
when power is cycled. To make the setting permanent,
the OTP register must be programmed by applying a
programming voltage.
The AS5043 is tolerant to magnet misalignment and
unwanted external magnetic fields due to differential
measurement technique and Hall sensor conditioning
circuitry.
It is also tolerant to airgap and temperature variations
due to Sin-/Cos- signal evaluation.
Sin
Cos
Ang
Mag
MagRNGn
Mode
DO
CLK
FB
Vout
Prog_DI
CSn
+
-
10
DACout
DACref
Figure 3: AS5043 block diagram
AS5043 Programmable 360° Magnetic Angle Encoder
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7 3.3V / 5V Operation
The AS5043 operates either at 3.3V ±10% or at 5V
±10%. This is made possible by an internal 3.3V Low-
Dropout (LDO) Voltage regulator. The core supply
voltage is always taken from the LDO output, as the
internal blocks are always operating at 3.3V.
For 3.3V operation, the LDO must be bypassed by
connecting VDD3V3 with VDD5V (see Figure 4 ).
For 5V operation, the 5V supply is connected to pin
VDD5V, while VDD3V3 (LDO output) must be buffered by
a 1...10µF capacitor, which should be placed close to the
supply pin (see).
The VDD3V3 output is intended for internal use only It
should not be loaded with an external load.
The voltage levels of the digital interface I/O’s
correspond to the voltage at pin VDD5V, as the I/O
buffers are supplied from this pin (see Figure 4).
Figure 4: Connections for 5V / 3.3V supply voltages
A buffer capacitor of 100nF is recommended in both
cases close to pin VDD5V. Note that pin VDD3V3 must
always be buffered by a capacitor. It must not be left
floating, as this may cause an instable internal 3.3V
supply voltage which may lead to larger than normal jitter
of the measured angle.
8 10-bit Absolute Synchronous
Serial Interface (SSI)
The serial data transmission timing is outlined in Figure
5: if CSn changes to logic low, Data Out (DO) will change
from high impedance (tri-state) to logic high and the
read-out sequence will be initiated.
After a minimum time tCLK FE, data is latched into the
output shift register with the first falling edge of CLK.
Each subsequent rising CLK edge shifts out one bit of
data.
The serial word contains 16 bits, the first 10 bits are the
angular information D[9:0], the subsequent 6 bits contain
system information, about the validity of data such as
OCF, COF, LIN, Parity and Magnetic Field status
(increase / decrease / out of range) .
A subsequent measurement is initiated by a logic “high”
pulse at CSn with a minimum duration of tCSn.
Data transmission may be terminated at any time by
pulling CSn = high.
8.1 Serial Data Contents:
D9:D0 absolute angular position data (MSB is clocked
out first).
OCF (Offset Compensation Finished), logic high
indicates that the Offset Compensation Algorithm has
finished and data is valid.
COF (Cordic Overflow), logic high indicates an out of
range error in the CORDIC part. When this bit is set, the
data at D9:D0 is invalid. The absolute output maintains
the last valid angular value.
This alarm may be resolved by bringing the magnet
within the X-Y-Z tolerance limits.
LIN (Linearity Alarm), logic high indicates that the input
field generates a critical output linearity.
When this bit is set, the data at D9:D0 may still be used,
but may contain invalid data. This warning may be
resolved by bringing the magnet within the X-Y-Z
tolerance limits.
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Data D9:D0 is valid, when the status bits have the
following configurations:
OCF COF LIN Mag
INC Mag
DEC Parity
0 0
0 1 1 0 0
1 0
even
checksum
of bits 1:15
Table 2: Status bit outputs
MagInc, (Magnitude Increase) becomes HIGH, when the
magnet is pushed towards the IC, thus the magnetic field
strength is increasing.
MagDec, (Magnitude Decrease) becomes HIGH, when
the magnet is pulled away from the IC, thus the magnetic
field strength is decreasing.
Both signals HIGH indicate a magnetic field that is out of
the allowed range (see Table 3).
Note: Pin 1 (MagRngn) is a combination of MagInc and
MagDec. It is active low via an open drain output and
requires an external pull-up resistor. If the magnetic field
is in range, this output is turned off. (logic “high”).
Even Parity bit for transmission error detection of bits
1…15 (D9…D0, OCF, COF, LIN, MagInc, MagDec)
The absolute angular output is always set to a resolution
of 10 bit / 360°. Placing the magnet above the chip,
angular values increase in clockwise direction by default.
Even
PAR
CSn
CLK
DO D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
18 16
COF LINOCF Mag
INC
Mag
DEC
t DO active t DO Tristate
1
D9
t CLK FE
t DO valid
t CLK FE
t CSn T CLK / 2
Angular Position Data Status Bits
Figure 5: Synchronous serial interface with absolute angular position data
8.2 Z-Axis Range Indication (Push Button Feature, Red/Yellow/Green Indicator)
The AS5043 provides several options of detecting
movement and distance of the magnet in the vertical (Z-)
direction. Signal indicators MagINC, MagDEC and LIN
are available as status bits in the serial data stream,
while MagRngn is an open-drain output that indicates an
out-of range status (on in YELLOW or RED range).
Additionally, the analog output provides a safety feature
in the form that it will be turned off when the magnetic
field is too strong or too weak (RED range).
The serial data is always available, the red/yellow/green
status is indicated by the status bits as shown below:
SSI Status bits Hardware Pins
Mag
INC Mag
DEC LIN Mag
Rngn
Analog
output
Description
0 0 0 Off enabled
No distance change
Magnetic Input Field OK (GREEN range, ~45…75mT)
0 1 0 Off enabled
Distance increase, GREEN range; Pull-function. This state is dynamic and only active while the magnet is
moving away from the chip.
1 0 0 Off enabled
Distance decrease, GREEN range; Push- function. This state is dynamic and only active while the magnet is
moving towards the chip.
1 1 0 On enabled
YELLOW Range: Magnetic field is ~ 25…45mT or ~75…135mT. The AS5043 may still be operated in this
range, but with slightly reduced accuracy.
1 1 1 On disabled
RED Range: Magnetic field is ~<25mT or >~135mT. The analog output will be turned off in this range by
default. It can be enabled permanently by OTP programming (see 11.1.2).
It is still possible to use the absolute serial interface in the red range, but not recommended.
Table 3: Magnetic field strength indicators
AS5043 Programmable 360° Magnetic Angle Encoder
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AS5043
1st Device
ProgDO
CLKCSn
CLK
µC
Prog DO
CLK CSn
ProgDO
CLKCSn
Data IN
CSn
AS5043
2nd Device AS5043
last Device
Figure 6: Daisy Chain hardware configuration
9 Mode Input Pin
The absolute angular position is sampled at a rate of
10.4kHz (t=96µs) in fast mode and at a rate of 2.6kHz
(t=384µs) in slow mode.
These modes are selected by pin MODE (#2). The mode
input pin activates or deactivates an internal filter, which
is used to reduce the digital jitter and consequently the
analog output noise.
Activating the filter by pulling Mode = LOW or leaving it
open reduces the transition noise to <0.03° rms. At the
same time, the sampling rate is reduced to 2.6kHz and
the signal propagation delay is increased to 384µs. This
mode is recommended for high precision, low speed and
≤360° applications.
Deactivating the filter by setting Mode = HIGH increases
the sampling rate to 10.4kHz and reduces the signal
propagation delay to 96µs. The transition noise will
increase to <0.06° rms. This mode is recommended for
higher speed and full scale = 360° applications.
Switching the MODE pin affects the following
parameters:
Parameter slow mode
(Pin MODE = 0 or
open)
fast mode
(Pin MODE = 1)
sampling rate 2.61 kHz
(383µs)
10.42 kHz
(95.9µs)
transition noise
(1 sigma)
≤ 0.03° rms ≤ 0.06° rms
propagation
delay
384µs 96µs
Startup time 20ms 80ms
Table 4: Mode pin settings
Pin MODE should be set at power-up. A mode change
during operation is not recommended.
10 Daisy Chain Mode
The Daisy Chain Mode allows connection of
several AS5043’s in series, while still
keeping just one digital input for data
transfer (See “Data IN” in Figure 6 ). This
mode is accomplished by connecting the
data output (DO; pin 9) to the data input
(PROG; pin 8) of the subsequent device.
The serial data of all connected devices is
read from the DO pin of the first device in
the chain. The length of the serial bit
stream increases with every connected
device, it is
n * (16+1) bits:
e.g. 34 bit for two devices, 51 bit for three devices, etc…
The last data bit of the first device (Parity) is followed by a dummy bit and the first data bit of the second
device (D9), etc… (see Figure 7)
Even
PAR
CSn
CLK
DO D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
18 16
COF LINOCF Mag
INC
Mag
DEC
1
tCLK FE
Angular Position Data Status Bits
TCLK/2
tDO active tDO va lid
D2
D9 D8 D7
1st Device 2nd Device
3
Angular Position Data
Figure 7: Daisy Chain data transfer timing diagram
AS5043 Programmable 360° Magnetic Angle Encoder
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11 Analog Output
The analog output Vout provides an analog voltage that is
proportional to the angle of the rotating magnet and
ratiometric to the supply voltage VDD5V (max.5.5V). It
can source or sink currents up to ±1mA in normal
operation (up to 66mA short circuit current).
The analog output block consists of a digital angular
range selector, a 10-bit Digital-to-Analog converter and
an OPAMP buffer stage (see Figure 14).
The digital range selector allows a preselection of the
angular range for 360°,180°,90° or 45° (see Table 5).
Fine-tuning of the angular range can be accomplished by
adjusting the gain of the OPAMP buffer stage.
The reference voltage for the Digital-to-Analog converter
(DAC) can be taken internally from VDD5V / 2. In this
mode, the output voltage is ratiometric to the supply
voltage.
Alternatively, an external DAC reference can be applied
at pin DACref (#9). In this mode, the analog output is
ratiometric to the external reference voltage.
An on-chip diagnostic feature turns the analog output off
in case of an error (broken supply or magnetic field out of
range; see Table 3).
The DAC output can be accessed directly at pin #10
DACout.
The addition of an OPAMP to the DAC output allows a
variety of user configurable options, such as variable
output voltage ranges and variable output voltage versus
angle response. By adding an external transistor, the
analog voltage output can be buffered to allow output
currents up to hundred milliamperes or more.
Furthermore, the OPAMP can be configured as constant
current source.
As an OTP option, the DAC can be configured to 2
different output ranges:
a) 0……100% VDACref. The reference point may be either
taken from VDD5V/2 or from the external DACref input.
The 0…100% range allows easy replacement of
potentiometers. Due to the nature of rail-to-rail outputs,
the linearity will degrade at output voltages that are close
to the supply rails.
b) 10…..90% VDACref. This range allows better linearity,
as the OPAMP is not driven to the rails. Furthermore, this
mode allows failure detection, when the analog output
voltage is outside of the normal operating range of
10…90%VDD, as in the case of broken supply or when
the magnetic field is out of range and the analog output
is turned off.
11.1 Analog o utput voltage modes
The Analog output voltage modes are programmable by OTP. Depending on the application, the analog output can be
selected as rail-to-rail output or as clamped output with 10%-90% VDD5V.
The output is ratiometric to the supply voltage (VDD5V), which can range from 3.0V to 5.5V. If the DAC reference is
switched to an external reference (pin DACref), the output is ratiometric to the external reference.
11.1.1 Full Scale Mo de
This output mode provides a ratiometric DAC output of (0% to 100%)x Vref *), amplified by the OPAMP stage (default =
internal 2x gain, see Figure 14)
Note: For simplification, Figure 8
describes a linear output voltage from
rail to rail (0V to VDD). In practice, this
is not feasible due to saturation effects
of the OPAMP output driver transistors.
The actual curve will be rounded
towards the supply rails (as indicated in
Figure 8).
Figure 8: Anal og output, full scale m ode (shown for 360°mode)
Vref
0° 90° 180° 270° 360°
0V
analog
output
voltage
angle
100%
AS5043 Programmable 360° Magnetic Angle Encoder
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Vref
0° 90° 180° 270°
360°
0%
analog
output
voltage
angle
100%
90%
10%
normal
operating
area
In an error case, the output
voltage is in the grey area
Note: Figure 8 and are shown for 360° operation. See Table 5 (page 12) for further angular range programming options.
11.1.2 Diagnostic Output Mode
In Diagnostic Output Mode (see Figure
9) the analog output of the internal DAC
ranges from 10% - 90% Vref*). In an
error case, either when the supply is
interrupted or when the magnetic field is
in the “red” range, (see Table 3) the
output is switched to 0V and thus
indicates the error condition.
Figure 9: Diagnostic Output Mode
It is possible to enable the analog output permanently (it will not be switched off even if the magnetic field is out of range).
To enable this feature an OTP bit in the factory setting must be set. The corresponding bit is FS6. See application note
AS5040-20 (Extended features of OTP programming) for further details. The application note is available for download at the
austriamicrosystems website.
The analog and digital outputs will have the following conditions:
Status DAC output voltage SSI digital output
normal operation 10% - 90% Vref*) #0 - #1023 (0°-360°),
MagRngn = 1
magnetic field out of range < 10% Vref*),
DAC output is
switched to 0V
#0 - #1023 (0°-360°)
out of range is signaled in status bits:
MagInc=MagDec=LIN=1, MagRngn= 0
broken positive power supply
(VOUT pull down resistor at receiving side)
< 10% VDD**)
broken power supply ground
(VOUT pull down resistor at receiving side)
< 10% VDD**)
broken positive power supply
(VOUT pull up resistor at receiving side)
> 90% VDD**)
broken power supply ground
(VOUT pull up resistor at receiving side)
> 90% VDD**)
with pull down resistor at DO (receiving
side), all bits read by the SSI will be
“0”-s, indicating a non-valid output
*) Vref = internal: ½ * VDD5V (pin #16) or external: VDACref (pin#9), depending on Ref_extEN bit in OTP (0=int., 1=ext.)
**) VDD = positive supply voltage at receiving side (3.0 – 5.5V)
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12 Programming the AS5043
After power-on, programming the AS5043 is enabled with
the rising edge of CSn and Prog = logic high. 16 bit
configuration data must be serially shifted into the OTP
register via the Prog-pin. The first “CCW” bit is followed
by the zero position data (MSB first) and the Analog
Output Mode setting as shown in Table 5. Data must be
valid at the rising edge of CLK (see Figure 10). Following
this sequence, the voltage at pin Prog must be raised to
the programming voltage VPROG (see Figure 11). 16 CLK
pulses (tPROG) must be applied to program the fuses. To
exit the programming mode, the chip must be reset by a
power-on-reset. The programmed data is available after
the next power-up.
Note: During the programming process, the transitions in
the programming current may cause high voltage spikes
generated by the inductance of the connection cable. To
avoid these spikes and possible damage to the IC, the
connection wires, especially the signals PROG and VSS
must be kept as short as possible. The maximum wire
length between the VPROG switching transistor and pin
PROG (Figure 12) should not exceed 50mm (2 inches).
To suppress eventual voltage spikes, a 10nF ceramic
capacitor should be connected close to pins PROG and
VSS. This capacitor is only required for programming, it
is not required for normal operation. The clock timing tclk
must be selected at a proper rate to ensure that the
signal PROG is stable at the rising edge of CLK (see
Figure 10). Additionally, the programming supply voltage
should be buffered with a 10µF capacitor mounted close
to the switching transistor. This capacitor aids in
providing peak currents during programming. The
specified programming voltage at pin PROG is 7.3 – 7.5V
(see section 19.7). To compensate for the voltage drop
across the VPROG switching transistor, the applied
programming voltage may be set slightly higher (7.5 -
8.0V, see Figure 12).
OTP Register Contents:
CCW Counter Clockwise Bit
ccw=0 – angular value increases with clockwise rotation
ccw=1 – angular value increases with counterclockwise rotation
Z [9:0]: Programmable Zero / Index Position
FB_intEN: OPAMP gain setting: 0=external, 1=internal
RefExtEN: DAC reference: 0=internal, 1=external
ClampMd EN: Analog output span: 0=0-100%,
1=10-90%*VDD
Output Range (OR0, OR1):
Analog Output Range Selection
[1:0] 00 = 360° 01 = 180°
10 = 90° 11 = 45°
Figure 10: Prog ramming Access – OTP W rite Cycle (section of Figure 11)
Figure 11: Complete OTP programming sequence
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USB
Figure 12: OTP programming hardware connection of AS5043 (shown with AS5043 demoboard)
12.1 Zero Positi on Programming
The AS5043 allows easy assembly of the system, as the
actual angle of the magnet does not need to be
considered. By OTP programming, any position can be
assigned as the new permanent zero position with an
accuracy of 0.35° (all modes).
Using the same procedure, the AS5043 can be calibrated
to assign a given output voltage to a given angle. With
this approach, all offset errors (DAC + OPAMP) are also
compensated for the calibrated position.
Essentially, for a given mechanical position, the angular
measurement system is electrically rotated (by changing
the Zero Position value in the OTP register), until the
output matches the desired mechanical position.
The example in Figure 13 below shows a configuration
for 5V supply voltage and 10%-90% output voltage
range. It adjusted by Zero Position Programming to
provide an analog output voltage of 2.0 Volts at an angle
of 180°. The slope of the curve may be further adjusted
by changing the gain of the OPAMP output stage and by
selecting the desired angular range (360°/180°/90°/45°).
Figure 13: Zero p osition programming (shown for 360° mode)
VDD5V
0° 90° 180° 270°
360°
analog
output
voltage
mechanical
angle
5V
2V
the output can be electrically rotated to
match a given output voltage to any
mechanical position
0V
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12.2 Analog Mode Progr amming
The analog output can be configured in many ways:
It consists of three major building blocks,
a digital range preselector,
a 10-bit Digital-to-Analog-Converter (DAC)
and an OP-AMP buffer stage.
In the default configuration (all OTP bits = 0), the analog output is set for 360° operation, internal DAC reference
(VDD5V/2), external OPAMP gain, 0-100% ratiometric to VDD5V.
Shown below is a typical example for a 0°-360° range, 0-5V output. The complete application requires only one external
component, a buffer capacitor at VDD3V3 and has only 3 connections VDD, VSS and Vout (connectors 1-3).
Note: the default setting for the OPAMP feedback path is:FB_intEn=0=external. The external resistors Rf and Rg must be
installed. In the programmed state (FB_intEn=1=internal), these resistors do not need to be installed as the feedback path is
internal (Rf_int and Rg_int).
AS5043
Range
Selector
OR1 OR0
ClampMdEN
0 360° 0
0 180° 1
1 90° 0
1 45° 1
10bit
digital
REF_extEN
0=int
DACref VDD5V
+
-
0 - 100% VDD5V /2
LDO
3.3V VDD3V3
916
15
DACout 10
VOUT 12
Rf_int
30k
Rg_int
30k
10bit
analog
FB 11
FB_intEN 1=int
Gain = 2x (int)
CL
<100pF
+
360°angle0
Vout
VDD
DAC
1=ext
0=ext
0= 0-100% * Vref (def.)
1= 10-90% * Vref
VDD5V / 2
Vref
VDD
VSS
1-10µF
7
PROGDOCLKCSn
for OTP
programming and
alignment mode
only. Leave open
or connect to VSS
if not used
Digital serial
interface, 10bit/360°.
Leave open if not
used. CSn and CLK
may also be tied to
VSS if not used
346 8
MagRngn Mode
Magnetic field range alarm. Active
low. Leave open or connect to
VSS if not used
Mode pin.
Default = open
(low noise)
OP-Amp feedback pin.
Leave open if not used.
DAC output pin.
Leave open if not used
External DAC reference pin.
Leave open or connect to
VSS if not used
NC
13
Test pins.
Leave open
NC
5
NC
14
2
1Connect pins 15 and
16 for VDD= 3.0-3.6V.
Do NOT connect for
VDD = 4.5-5.5V !
from
DSP
1
2
3
RLmin
= 4k7
Vout
VSS
Rf
Rg
Figure 14: analog output block diagram
AS5043 Programmable 360° Magnetic Angle Encoder
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12.2.1 Angular range Selector :
The Angular Range selector allows a digital pre-selection
of the angular range. The AS5043 can be configured for
a full scale angular range of 45°,90°,180° or 360°. In
addition, the Output voltage versus angle response can
be fine-tuned by setting the gain of the OP-AMP with
external resistors and the maximum output voltage can
be set in the DAC.
The combination of these options allows to configure the
operation range of the AS5043 for all angles up to 360°
and output voltages up to 5.5V
The response curve for the analog output is linear for the
selected range (45°/90°/180°/360°). In addition, the
slope is mirrored at 180° for 45°- and 90°- modes and
has a step response at 270° for the 180°-mode. This
allows the AS5043 to be used in a variety of applications.
In these three modes, the output remains at Vout,max and
Vout,min to avoid a sudden output change when the
mechanical angle is rotated beyond the selected analog
range. In 360°-mode, a jitter between Vout,max and Vout,min
at the 360° point is also prevented due to a hysteresis.
Output
Range1
Output
Range0 Mode Note
0 0
0
0° 256
90° 180° 270°
360°
0 angle*)
360° angular range (default)
1023
512 768 1024
default mode,
analog resolution= 10bit
(1024 steps) over 360°
analog step size:
1LSB = 0.35°
0 1
0
0° 90° 180° 270°
360°
0 angle
180° angular range
1023
256 512 768 1024
analog resolution= 10bit
(1024 steps) over 180°
Analog step size:
1LSB = 0.175°
1 0
0
0° 90° 180° 270°
360°
0 angle
90° angular range
1023
256 512 768 1024
analog resolution= 10bit
(1024 steps) over 90°
Analog step size:
1LSB = 0.088°
1 1
0
0° 90° 180°
225° 360°
0 angle
45° angular range
511
256 512
640 1024
128
45°
analog resolution=
9 bit (512 steps) over 45°
Analog step size:
1LSB = 0.088°
*) Note: the resolution on the digital SSI interface is always 10bit (0.35°/step) over 360°, independent on analog mode
Table 5: Digital Range Selector programming option
AS5043 Programmable 360° Magnetic Angle Encoder
Revision 1.6, 3-Oct-06 www.austriamicrosystems.com Page 13 of 26
12.3 Repeated OTP Pr ogramming
Although a single AS5043 OTP register bit can be
programmed only once (from 0 to 1), it is possible to
program other, unprogrammed bits in subsequent
programming cycles. However, a bit that has already
been programmed should not be programmed twice.
Therefore it is recommended that bits that are already
programmed are set to “0” during a programming cycle.
12.4 Non-permanent Pr ogramming
It is also possible to re-configure the AS5043 in a non-
permanent way by overwriting the OTP register.
This procedure is essentially a “Write Data” sequence
(see Figure 10) without a subsequent OTP programming
cycle.
The “Write Data” sequence may be applied at any time
during normal operation. This configuration remains set
while the power supply voltage is above the power-on
reset level (see 19.5).
See Application Note AN5000-20 for further information.
12.5 Digital-to- Analog Converter (DAC)
The DAC has a resolution of 10bit (1024 steps) and can
be configured for the following options
Internal or external reference
The default DAC reference is the voltage at pin #16
(VDD5V) divided by 2 (see Figure 14). Using this
reference, a system that has an output voltage
ratiometric to the supply voltage can be built.
Optionally, an external reference source, applied at pin#9
(DACref) can be used. This programming option is useful
for applications requiring a precise output voltage that is
independent of supply fluctuations, for current sink
outputs or for applications with a dynamic reference, e.g.
attenuation of audio signals.
0-100% or 10-90% full scale range
The reference voltage for the DAC is buffered internally.
The recommended range for the external reference
voltage is 0.2V to (VDD3V3 -0.2)V.
The DAC output voltage will be switched to 0V, when the
magnetic field is out of range, when the MagInc and
MagDec indicators are both =1 and the MagRngn-pin (#1)
will go low.
The default full scale output voltage range is 0-
100%*VDD5V. Due to limitations in the output stage of
an OP-Amp buffer, it cannot drive the output voltage from
0-100% rail-to-rail. Without load, the minimum output
voltage at 0° will be a few millivolts higher than 0V and
the maximum output voltage will be slightly lower than
VDD5V . With increasing load, the voltage drops will
increase accordingly.
As a programming option, an output range of 10-
90%*VDD5V can be selected. In this mode, there is no
saturation at the upper and lower output voltage limits
like in the 0-100% mode and it allows failure detection as
the output voltage will be outside the 10-90% limits,
when the magnetic field is in the “red” range (Vout=0V,
see Table 3) or when the supply to the chip is interrupted
(Vout=0V or VDD5V).
The unbuffered output of the DAC is accessible at pin
#10 (DACout). This output must not be loaded.
12.6 OP-AMP st age
The DAC output is buffered by a non-inverting Op-Amp
stage. The amplifier is supplied by VDD5V (pin #16) and
can hence provide output voltages up to 5V.
By allowing access to the inverting input of the Op-Amp
and with the addition of a few discrete components it can
be configured in many ways, like high current buffer,
current sink output, adjustable angle range, etc...
Per default, the gain of the Op-Amp must be set by two
external resistors (see Figure 14). Optionally, the fixed
internal gain setting (2x) may be programmed by OTP,
eliminating the need for external resistors.
12.6.1 Output Noise
The Noise level at the analog output depends on two
states of the digital angular output:
a) the digital angular output value is stable
In this case, the output noise is the figure given
as Vnoise in paragraph 19.3.6. Note that the
noise level is given for the default gain of 2x
For other gains, it must be scaled accordingly.
b) the digital output is at the edge of a step
In this case, the digital output may jitter
between two adjacent values. The rate of jitter
is specified as transition noise (parameter TN
in paragraph 19.5). The resulting output noise
is calculated by:
OPAMPnoiseVoutnoise V
VVDDTN
V,, 360 5+
∗
=
AS5043 Programmable 360° Magnetic Angle Encoder
Revision 1.6, 3-Oct-06 www.austriamicrosystems.com Page 14 of 26
where:
Vnoise, Vout = noise level at pin Vout in Vrms
TN = transition noise (in °rms; see 19.5)
VDD5V = Supply voltage VDD5V in V
Vnoise,OPAMP = noise level of OPAMP
(paragraph 19.3.6) in Vrms
12.7 Application Examples
See Application Note AN5043-10 for AS5043 Application
Examples.
13 Analog Readback Mode
Non-volatile programming (OTP) uses on-chip zener
diodes, which become permanently low resistive when
subjected to a specified reverse current.
The quality of the programming process depends on the
amount of current that is applied during the programming
process (up to 130mA). This current must be provided by
an external voltage source. If this voltage source cannot
provide adequate power, the zener diodes may not be
programmed properly.
In order to verify the quality of the programmed bits, an
analog level can be read for each zener diode, giving an
indication whether this particular bit was properly
programmed or not.
To put the AS5043 in Analog Readback Mode, a digital
sequence must be applied to pins CSn, PROG and CLK
as shown in Figure 15. The digital level for this pin
depends on the supply configuration (3.3V or 5V; see
section 7, page 4).
The second rising edge on CSn (OutpEN) changes pin
PROG to a digital output and the log. high signal at pin
PROG must be removed to avoid collision of outputs
(grey area in Figure 15).
The following falling slope of CSn changes pin PROG to
an analog output, providing a reference voltage Vref, that
must be saved as a reference for the calculation of the
subsequent programmed and unprogrammed OTP bits.
Following this step, each rising slope of CLK outputs one
bit of data in the reverse order as during programming.
(see Figure 15: Output Range OR0 and -1 , ClampMdEn,
RefExtEn, FB_IntEn, Z0…Z9, ccw)
During analog readback, the capacitor at pin PROG (see
Figure 12) should be removed to allow a fast readout
rate.
The measured analog voltage for each bit must be
subtracted from the previously measured Vref, and the
resulting value gives an indication on the quality of the
programmed bit: a reading of <100mV indicates a
properly programmed bit and a reading of >1V indicates
a properly unprogrammed bit.
A reading between 100mV and 1V indicates a faulty bit,
which may result in an undefined digital value, when the
OTP is read at power-up.
Following the 16th clock (after reading bit “ccw”), the chip
must be reset by disconnecting the power supply.
Inte rn al
tes t bit
digital Vunpro
g
rammed
V
p
ro
g
rammed
CSn
CLK 1 16
PROG
ProgEN
OR1OR0
Analog R eadback Data at PR O G OutpEN
tLoadProg CLK
A
read
Prog changes to Ou tput
Vref
P
ower-on-
Reset;
cycle
supply
RefExt
EN
Clamp
MdEN Z6 Z5 Z8 Z7 ccw Z9
Figure 15:Analog OTP Register Read
AS5043 Programmable 360° Magnetic Angle Encoder
Revision 1.6, 3-Oct-06 www.austriamicrosystems.com Page 15 of 26
14 Alignment Mode
The alignment mode simplifies centering the magnet over
the chip to gain maximum accuracy and XY-alignment
tolerance.
This electrical centering method allows a wider XY-
alignment tolerance (0.485mm radius) than mechanical
centering (0.25mm radius) as it eliminates the placement
tolerance of the die within the IC package (+/- 0.235mm).
Alignment mode can be enabled with the falling edge of
CSn while PROG = logic high (Figure 16). The Data bits
D9-D0 of the SSI change to a 10-bit displacement
amplitude output. A high value indicates large X or Y
displacement, but also higher absolute magnetic field
strength. The magnet is properly aligned, when the
difference between highest and lowest value over one full
turn is at a minimum.
Under normal conditions, a properly aligned magnet will
result in a reading of less than 32 over a full turn.
Stronger magnets or short gaps between magnet and IC
may show values larger than 32. These magnets are still
properly aligned as long as the difference between
highest and lowest value over one full turn is at a
minimum.
The MagInc and MagDec indicators will be = 1 when the
alignment mode reading is < 32. At the same time,
hardware pin MagRngn (#1) will be pulled to VSS.
The Alignment mode can be reset to normal operation
mode by a power-on-reset (cycle power supply) or by a
falling edge of CSn with PROG=low (see Figure 17).
AlignMode enable
PRO
G
CSn Read-out
via SSI
2µs
min. 2µs
min.
Figure 16: Enabling the alignment mode
exit AlignMode
PRO
G
CSn
Read-out
via SSI
Figure 17:Exiting alignment mode
15 Choosing the proper Magnet
Typically the magnet should be 6mm in diameter and ≥2.5mm in
height. Magnetic materials such as rare earth AlNiCo, SmCo5 or
NdFeB are recommended.
The magnet’s field strength perpendicular to the die
surface should be verified using a gauss-meter. The
magnetic field Bv at a given distance, along a concentric
circle with a radius of 1.1mm (R1), should be in the range
of ±45mT…±75mT. (see Figure 18).
Magnet axis
Vertical field
component
(45…75mT)
0
360
360
Bv
Vertical field
component
R1 concentric circle;
radius 1.1mm
R1
Magnet axis
typ. 6mm diameter
SN
Figure 18: Typical magnet and magnetic field distribution
AS5043 Programmable 360° Magnetic Angle Encoder
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15.1 Physi cal Placement of the Magnet
The best linearity can be achieved by placing the center
of the magnet exactly over the defined center of the IC
package as shown in Figure 19:
1
Defined
center
2.433 mm
2.433 mm
3.9 mm 3.9 mm
A
rea of recommended maximum
magnet misalignment
Rd
Figure 19: Defined IC center and magnet displacement radius
15.1.1 Magnet Placement:
The magnet’s center axis should be aligned within a
displacement radius Rd of 0.25mm from the defined
center of the IC with reference to the edge of pin #1 (see
Figure 19). This radius includes the placement tolerance
of the chip within the SSOP-16 package (+/- 0.235mm).
The displacement radius Rd is 0.485mm with reference to
the center of the chip (see section 14: Alignment Mode).
The vertical distance should be chosen such that the
magnetic field on the die surface is within the specified
limits (see Figure 18). The typical distance “z” between
the magnet and the package surface is 0.5mm to 1.8mm
with the recommended magnet (6mm x 3mm). Larger
gaps are possible, as long as the required magnetic field
strength stays within the defined limits.
A magnetic field outside the specified range may still
produce usable results, but the out-of-range condition
will be indicated by MagRngn (pin 1), which will be pulled
low. At this condition, the angular data is still available
over the digital serial interface (SSI), but the analog
output will be turned off.
1.282mm ± 0.15mm
0.576mm ± 0.1mm
z
SN
Package surfaceDie surface
Figure 20: Vertical placement of the magnet
16 Simulation Modelling
Figure 21: Ar rangement of Hall sen sor array on chip (pri nciple)
With reference to Figure 21, a diametrically magnetized
permanent magnet is placed above or below the surface
of the AS5043. The chip uses an array of Hall sensors to
sample the vertical vector of a magnetic field distributed
across the device package surface. The area of magnetic
sensitivity is a circular locus of 1.1mm radius with
respect to the center of the die. The Hall sensors in the
area of magnetic sensitivity are grouped and configured
such that orthogonally related components of the
magnetic fields are sampled differentially.
The differential signal Y1-Y2 will give a sine vector of
the magnetic field. The differential signal X1-X2 will give
an orthogonally related cosine vector of the magnetic
field.
The angular displacement (Θ) of the magnetic source
with reference to the Hall sensor array may then be
modelled by:
(
)
()
°±
−
−
=Θ 5.0
21 21
arctan XX YY
The ±0.5° angular error assumes a magnet optimally
aligned over the center of the die and is a result of gain
mismatch errors of the AS5043. Placement tolerances of
the die within the package are ±0.235mm in X and Y
direction, using a reference point of the edge of pin #1
(Figure 21)
In order to neglect the influence of external disturbing
magnetic fields, a robust differential sampling and
ratiometric calculation algorithm has been implemented.
A
S5043 die
1
Radius of circular Hall sensor
array: 1.1mm radius
Center of die
2.433 mm
±0.235mm
3.9 mm ±0.235mm
X1
Y1
X2
Y2
AS5043 Programmable 360° Magnetic Angle Encoder
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The differential sampling of the sine and cosine vectors
removes any common mode error due to DC components
introduced by the magnetic source itself or external
disturbing magnetic fields. A ratiometric division of the
sine and cosine vectors removes the need for an
accurate absolute magnitude of the magnetic field and
thus accurate Z-axis alignment of the magnetic source.
The recommended differential input range of the
magnetic field strength (B(X1-X2),B(Y1-Y2)) is ±75mT at the
surface of the die. In addition to this range, an additional
offset of ±5mT, caused by unwanted external stray fields
is allowed.
The chip will continue to operate, but with degraded
output linearity, if the signal field strength is outside the
recommended range. Too strong magnetic fields will
introduce errors due to saturation effects in the internal
preamplifiers. Too weak magnetic fields will introduce
errors due to noise becoming more dominant.
17 Failure Diagnostics
The AS5043 also offers several diagnostic and failure
detection features:
17.1 Magnetic field str ength diagnosis
By software: the MagInc and MagDec status bits will
both be high when the magnetic field is out of range.
By hardware: Pin #1 (MagRngn) is a logical NAND-ed
combination of the MagInc and MagDec status bits. It is
an open-drain output and will be turned on (= low with
external pull-up resistor) when the magnetic field is out
of range.
By hardware: Pin #12 (Vout) is the analog output of the
DAC and OP-Amp. The analog output will be 0V, when
the magnetic field is out of range (all analog modes).
17.2 Power supply failure detection
By software: If the power supply to the AS5043 is
interrupted, the digital data read by the SSI will be all
“0”s. Data is only valid, when bit OCF is high, hence a
data stream with all “0”s is invalid. To ensure adequate
low levels in the failure case, a pull-down resistor
(~10kΩ) should be added between pin DO and VSS at
the receiving side
By hardware: The MagRngn pin is an open drain output
and requires an external pull-up resistor. In normal
operation, this pin is high ohmic and the output is high.
In a failure case, either when the magnetic field is out of
range or the power supply is missing, this output will
become low. To ensure an adequate low level in case of
a broken power supply to the AS5043, the pull-up
resistor (~10kΩ) must be connected to the positive
supply at pin 16 (VDD5V).
.
18 Angular Output tolerances
18.1 Accuracy; digital outputs
Accuracy is defined as the error between measured
angle and actual angle. It is influenced by several
factors:
the non-linearity of the analog-digital converters,
internal gain and mismatch errors,
non-linearity due to misalignment of the magnet
As a sum of all these errors, the accuracy with centered
magnet = (Errmax – Errmin)/2 is specified as better than
±0.5 degrees @ 25°C (see Figure 23).
Misalignment of the magnet further reduces the
accuracy. Figure 22 shows an example of a 3D-graph
displaying non-linearity over XY-misalignment. The
center of the square XY-area corresponds to a centered
magnet (see dot in the center of the graph). The X- and
Y- axis extends to a misalignment of ±1mm in both
directions. The total misalignment area of the graph
covers a square of 2x2 mm (79x79mil) with a step size of
100µm.
For each misalignment step, the measurement as shown
in Figure 23 is repeated and the accuracy
(Errmax – Errmin)/2 (e.g. 0.25° in Figure 23) is entered as
the Z-axis in the 3D-graph.
18.2 Accuracy; anal og output
The analog output has the same accuracy as the digital
output with the addition of the nonlinearities of the DAC
and the OPAMP (+/-1LSB; see Table 5 and 19.3.5).
-1000
-700
-400
-100
200
500
800
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
0
1
2
3
4
5
6
°
x
y
Linearity Error over XY-misalignm ent [°]
Figure 22: Ex ample of linearity er ror over XY misalignm ent
AS5043 Programmable 360° Magnetic Angle Encoder
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The maximum non-linearity error on this example is
better than ±1 degree (inner circle) over a misalignment
radius of ~0.7mm. For volume production, the placement
tolerance of the IC within the package (±0.235mm) must
also be taken into account.
The total nonlinearity error over process tolerances,
temperature and a misalignment circle radius of 0.25mm
is specified better than ±1.4 degrees.
The magnet used for these measurement was a cylindrical
NdFeB (Bomatec® BMN-35H) magnet with 6mm diameter and
2.5mm in height.
Figure 23: Ex ample of linearity er ror over 360°
18.3 Transition Noi se
Transition noise is defined as the jitter in the transition
between two steps.
Due to the nature of the measurement principle (Hall
sensors + Preamplifier + ADC), there is always a certain
degree of noise involved.
This transition noise voltage results in an angular
transition noise at the outputs. It is specified as 0.06
degrees rms (1 sigma)*1 in fast mode (pin MODE = high)
and 0.03 degrees rms (1 sigma)*1 in slow mode (pin
MODE = low or open).
These values are the repeatability of an indicated angle
at a given mechanical position.
The transition noise has different implications on the type
of output that is used:
absolute output; SSI interface:
The transition noise of the absolute output can
be reduced by the user by applying an
averaging of readings. An averaging of 4
readings will reduce the transition noise by 6dB
or 50%, e.g. from 0.03°rms to 0.015°rms (1
sigma) in slow mode
analog output:
Ideally, the analog output should have a jitter
that is less than one digit. In 360° mode, both
fast or slow mode may be selected for adequate
low jitter.
In 180°, 90° or 45° mode, where the step sizes
are smaller, slow mode should be selected to
reduce the output jitter.
*1: statistically, 1 sigma represents 68.27% of readings,
3 sigma represents 99.73% of readings.
18.4 High Speed Operation
18.4.1 Sampling rate
The AS5043 samples the angular value at a rate of
10.42k samples per second (ksps) in fast mode and
2.61ksps in slow mode.
Consequently, a new reading is performed each 96µs.
(fast mode) or 384µs (slow mode).
At a stationary position of the magnet, this sampling rate
creates no additional error.
Absolute Mode:
With the given sampling rates, the number of samples (n)
per turn for a magnet rotating at high speed can be
calculated by
srpm
n
μ
96
60
⋅
= for fast mode
srpm
n
μ
384
60
⋅
=for slow mode
linearit
y
error with centered ma
g
net
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
1 55 109 163 217 271 325 379 433
487
541
595
649
703
757
811
865
919 973
transition noise
Err
max
Err
min
AS5043 Programmable 360° Magnetic Angle Encoder
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In practice, there is no upper speed limit. The only restriction is
that there will be fewer samples per revolution as the speed
increases.
Regardless of the rotational speed, the absolute angular value is
always sampled at the highest resolution.
Fast Mode
(pin Mode = 1)
Slow Mode
(pin Mode = 0 or open)
610rpm = 1024 samples / turn 610rpm = 256 samples / turn
1220rpm = 512 samples / turn 1220rpm = 128 samples / turn
2441rpm = 256 samples / turn 2441rpm = 64 samples / turn
etc… etc…
Table 6: Speed p erformance
18.5 Output delays
The propagation delay is the delay between the time that
the sample is taken until it is available as angular data.
This delay is 96µs in fast mode (pin Mode = high) and
384µs in slow mode (pin Mode = low or open)
The analog output produces no further delay, the output
voltage will be updated as soon as it is available. Using
the SSI interface for data transmission, an additional
delay must be considered, caused by the asynchronous
sampling (0….1/fsample) and the time it takes the external
control unit to read and process the angular data from
the AS5043.
18.5.1 Angular error caused by propagation
delay
A rotating magnet will cause an angular error caused by
the propagation delay.
This error increases linearly with speed:
delayprrpmesampling .6(deg) ∗∗=
where esampling = angular error [°]
rpm = rotating speed [rpm]
prop.delay = propagation delay [seconds]
Note: since the propagation delay is known, it can be
automatically compensated by the control unit processing
the data from the AS5043.
Internal timing tolerance
The AS5043 does not require an external ceramic
resonator or quartz. All internal clock timings for the
AS5043 are generated by an on-chip RC oscillator. This
oscillator is factory trimmed to ±5% accuracy at room
temperature (±10% over full temperature range). This
tolerance influences the ADC sampling rate:
18.5.2 absolute output; SSI interface:
A new angular value is updated every
96µs +/- 5% (Mode = 1) or
384µs +/- 5% (Mode = 0 or open)
18.6 Temper ature
18.6.1 Magnetic temperature coefficient
One of the major benefits of the AS5043 compared to
linear Hall sensors is that it is much less sensitive to
temperature. While linear Hall sensors require a
compensation of the magnet’s temperature coefficients,
the AS5043 automatically compensates for the varying
magnetic field strength over temperature. The magnet’s
temperature drift does not need to be considered, as the
AS5043 operates with magnetic field strengths from
±45…±75mT.
Example:
A NdFeB magnet has a field strength of 75mT @ –40°C and a
temperature coefficient of -0.12% per Kelvin. The temperature
change is from –40° to +125° = 165K.
The magnetic field change is: 165 x -0.12% = -19.8%, which
corresponds to 75mT at –40°C and 60mT at 125°C .
The AS5043 can compensate for this temperature related
field strength change automatically, no user adjustment
is required.
18.6.2 Accuracy ove r Temperature
The influence of temperature in the absolute accuracy is
very low. While the accuracy is ≤ ±0.5° at room
temperature, it may increase to ≤±0.9° due to increasing
noise at high temperatures.
18.6.3 Timing tolerance over temperature
The internal RC oscillator is factory trimmed to ±5%.
Over temperature, this tolerance may increase to ±10%.
Generally, the timing tolerance has no influence in the
accuracy or resolution of the system, as it is used mainly
for internal clock generation.
Revision No., Date Page 20 of 26
19 Electrical Characteristics
19.1 Absol ute Maximum Ratings (non operating)
Stresses beyond those listed under “Absolute Maximum Ratings“ may cause permanent damage to the device. These are stress
ratings only. Functional operation of the device at these or any other conditions beyond those indicated under “Operating
Conditions” is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Parameter Symbol Min Max Unit Note
VDD5V -0.3 7 V Pin VDD5V
DC supply voltage
VDD3V3 5 V Pin VDD3V3
-0.3 VDD5V +0.3 Pins MagRngn, Mode, CSn, CLK, DO, DACout, FB,
Vout
-0.3 5 Pin DACref
Input pin voltage Vin
-0.3 7.5
V
Pin PROG_DI
Input current (latchup immunity) Iscr -100 100 mA
Norm: JEDEC 78
Electrostatic discharge ESD ± 2 kV Norm: MIL 883 E method 3015
Storage temperature Tstrg -55 125 °C Min – 67°F ; Max +257°F
Body temperature (Lead-free package) TBody 260 °C
t=20 to 40s, Norm: IPC/JEDEC J-Std-020C
Lead finish 100% Sn “matte tin”
Humidity non-condensing H 5 85 %
19.2 Operating Conditi ons
Parameter Symbol Min Typ Max Unit Note
Ambient temperature Tamb -40 125 °C -40°F…+257°F
Supply current Isupp 16 21 mA
Supply voltage at pin VDD5V
Voltage regulator output voltage at pin VDD3V3
VDD5V
VDD3V3
4.5
3.0
5.0
3.3
5.5
3.6
V
V
5V Operation
Supply voltage at pin VDD5V
Supply voltage at pin VDD3V3
VDD5V
VDD3V3
3.0
3.0
3.3
3.3
3.6
3.6
V
V
3.3V Operation
(pin VDD5V and VDD3V3 connected)
19.3 DC Charact eristics for Digital Inputs and Outputs
19.3.1 CMOS Schmitt-Trigger Inpu ts: CLK, CSn (internal Pull-up), Mode (internal Pull-down)
(operating conditions: Tamb = -40 to +125°C, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation) unless otherwise noted)
Parameter Symbol Min Max Unit Note
High level input voltage VIH 0.7 * VDD5V V Normal operation
Low level input voltage VIL 0.3 * VDD5V
V
Schmitt Trigger hysteresis VIon- VIoff 1 V
-1 1 Pin CLK, VDD5V = 5.0V Input leakage current
Pull-up low level input current
Pull-down high level input current
ILEAK
IiL
IiH
-30
30
-100
100
µA Pin CSn, VDD5V= 5.0V
Pin Mode, VDD5V= 5.0V
AS5043 Programmable 360° Magnetic Angle Encoder
Revision 1.6, 3-Oct-06 www.austriamicrosystems.com Page 21 of 26
19.3.2 CMOS input : Program Input (Prog)
(operating conditions: Tamb = -40 to +125°C, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation) unless
otherwise noted)
Parameter Symbol Min Max Unit Note
High level input voltage VIH 0.7 * VDD5V 5 V
High level input voltage VPROG See “programming conditions” V During programming
Low level input voltage VIL 0.3 * VDD5V V
Pull-down high level input current IiL 100 µA VDD5V: 5.5V
19.3.3 CMOS Output Open Drain: MagRngn
(operating conditions: Tamb = -40 to +125°C, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation) unless
otherwise noted)
Parameter Symbol Min Max Unit Note
Low level output voltage VOL VSS+0.4 V
Output current IO
4
2
mA
VDD5V: 4.5V
VDD5V: 3V
Open drain leakage current IOZ 1 µA
19.3.4 Tristate CMOS Output: DO
(operating conditions: Tamb = -40 to +125°C, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation) unless otherwise noted)
Parameter Symbol Min Max Unit Note
High level output voltage VOH VDD5V –0.5 V
Low level output voltage VOL VSS+0.4 V
Output current IO 4
2
mA
mA
VDD5V: 4.5V
VDD5V: 3V
Tri-state leakage current IOZ 1 µA
19.3.5 Digital-to-Analog Converter
Parameter Symbol Min Typ Max Unit Note OTP setting
Resolution 10 bit
Output Range VOUTM1 0 Vref V 0……100% Vref (default) ClampMdEn = 0 (default)
V
OUTM2 0.10 *Vref 0.90 *Vref V 10…..90% Vref ClampMdEn = 1
Output resistance ROut,DAC 8 kΩ Unbuffered Pin DACout (#10)
0.2 VDD3V3 - 0.2 V DAC reference = external:
Pin: DACref (#9) RefExt EN = 1
DAC reference voltage
(DAC full scale range) Vref
VDD5V / 2 V DAC reference = internal RefExtEn = 0 (default)
Integral Non-Linearity INLDAC +/- 1.5 LSB
Differential Non-Linearity DNLDAC +/- 0.5 LSB
Non-Linearity of DAC and
OPAMP; -40….+125°C, For all
analog modes:
1LSB = Vref / 1024
1 LSB All analog modes
Analog output hysteresis Hyst
2 LSB
At 360°-0° transition,
360° mode only
OR1,OR0 = 00 (default)
AS5043 Programmable 360° Magnetic Angle Encoder
Revision 1.6, 3-Oct-06 www.austriamicrosystems.com Page 22 of 26
19.3.6 OPAMP output stage
Parameter Symbol Min Typ Max Unit Note
Power Supply Range VDD5V 3.0 5.5 V
Parallel Load Capacitance CL 100 pF
Parallel Load Resistance RL 4.7 kΩ 3.3V operation
Open Loop Gain A0 92 130 144 dB
Offset Voltage RTI VosOP -5 5 mV 3 sigma
Output Range Low VoutL 0.05 * VDD5V V
Output Range High VoutH 0.95 * VDD5V V
Linear range of analog output
current capability sink Isink 4.8 50 mA
Permanent short circuit current:
Vout to VDD5V
current capability source Isource 4.6 66 mA
Permanent short circuit current:
Vout to VSS
Output noise Vnoise 160 220 490 µVrms
Over full temperature range;
BW= 1Hz…10MHz,Gain = 2x
2 Internal; OTP: FB_int EN = 1
OPAMP gain (non-inverting) Gain
1 4
External OTP: FB_int EN = 0
(default)
With external resistors, pins Vout
[#12] and FB [#11]: see Figure 14
19.4 Magnetic Input Specification
(operating conditions: Tamb = -40 to +125°C, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation)
unless otherwise noted)
Two-pole cylindrical diametrically magnetised source:
Parameter Symbol Min Typ Max Unit Note
Diameter dmag 4 6 mm
Thickness tmag 2.5 mm
Recommended magnet: Ø 6mm x 2.5mm for cylindrical
magnets
Magnetic input field amplitude Bpk 45
75 mT
Required vertical component of the magnetic field strength on
the die’s surface, measured along a concentric circle with a
radius of 1.1mm
Magnetic offset Boff ± 10 mT Constant magnetic stray field
Field non-linearity 5 % Including offset gradient
fmag_abs
10 Hz
Absolute mode: 600 rpm @ readout of 1024 positions
(see table 6)
Input frequency
(rotational speed of magnet)
fmag_inc
166 Hz
Incremental mode: no missing pulses at rotational speeds of
up to 10,000 rpm (see table 6)
Displacement radius Disp 0.25 mm Max. offset between defined device center and magnet axis
-0.12 NdFeB (Neodymium Iron Boron)
Recommended magnet material
and temperature drift
-0.035
%/K
SmCo (Samarium Cobalt)
AS5043 Programmable 360° Magnetic Angle Encoder
Revision 1.6, 3-Oct-06 www.austriamicrosystems.com Page 23 of 26
19.5 Electrical System Specificatio ns
(operating conditions: Tamb = -40 to +125°C, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation)
unless otherwise noted)
Parameter Symbol Min Typ Max Unit Note
Resolution* RES 10 bit 0.352 deg
Integral non-linearity (optimum) * INLopt ± 0.5 deg
Maximum error with respect to the best line fit.
Verified at optimum magnet placement, Tamb =25 °C.
Integral non-linearity (optimum) * INLtemp ± 0.9 deg
Maximum error with respect to the best line fit.
Verified at optimum magnet placement ,
Tamb = -40 to +125°C
Integral non-linearity* INL ± 1.4 deg
Best line fit = (Errmax – Errmin) / 2
Over displacement tolerance with 6mm diameter magnet,
Tamb = -40 to +125°C
Differential non-linearity* DNL ± 0.176 deg 10bit, no missing codes
0.06 1 sigma, fast mode (pin MODE = 1)
Transition noise* TN
0.03
Deg
RMS 1 sigma, slow mode (pin MODE=0 or open)
Power-on reset thresholds
On voltage; 300mV typ. hysteresis
Off voltage; 300mV typ. hysteresis
Von
Voff
1,37
1.08
2.2
1.9
2.9
2.6
V
V
DC supply voltage 3.3V (VDD3V3)
DC supply voltage 3.3V (VDD3V3)
20 fast mode (pin MODE=1)
Power-up time,
Until offset compensation finished,
OCF = 1, Angular Data valid
tPwrUp
80
ms
slow mode (pin MODE=0 or open)
96 fast mode (pin MODE=1) System propagation delay
absolute output : delay of ADC and
DSP
tdelay
384
µs
slow mode (pin MODE=0 or open)
2.48 2.61 2.74 Tamb = 25°C, slow mode (pin MODE=0 or open)
Internal sampling rate for absolute
output: fS,mode0
2.35 2.61 2.87
kHz
Tamb = -40 to +125°C, slow mode (pin MODE=0 or open)
9.90 10.42 10.94 Tamb = 25°C, fast mode (pin MODE = 1)
Internal sampling rate for absolute
output fS,mode1
9.38 10.42 11.46
kHz
Tamb = -40 to +125°C, : fast mode (pin MODE = 1)
Read-out frequency CLK >0 1 MHz Max. clock frequency to read out serial data
*)digital interface
1
80° 360 °
0°
0
512
1023
α
α10bit code
0
1
2
0.35°
INL
Ideal curve
Actual curve
TN
512
1023
DNL+1LSB
[degrees]
Figure 24: Integral and differential Non-Linearity (exaggerated curve)
AS5043 Programmable 360° Magnetic Angle Encoder
Revision 1.6, 3-Oct-06 www.austriamicrosystems.com Page 24 of 26
Integral Non-Linearity (INL) is the maximum deviation between actual position and indicated position.
Differential Non-Linearity (DNL) is the maximum deviation of the step length from one position to the next.
Transition Noise (TN) is the repeatability of an indicated position.
19.6 Timing Characteristi cs
Synchronous Serial Interface (SSI)
(operating conditions: Tamb = -40 to +125°C, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation) unless
otherwise noted)
Parameter Symbol Min Typ Max Unit Note
Data output activated (logic high) t DO active 100 ns Time between falling edge of CSn and data output activated
First data shifted to output register tCLK FE 500 ns
Time between falling edge of CSn and first falling edge of
CLK
Start of data output T CLK / 2 500 ns Rising edge of CLK shifts out one bit at a time
Data output valid t DO valid 357 375 394 ns Time between rising edge of CLK and data output valid
Data output tristate t DO tristate 100 ns After the last bit DO changes back to “tristate”
Pulse width of CSn t CSn 500 ns CSn = high; To initiate read-out of next angular position
Read-out frequency fCLK >0 1 MHz Clock frequency to read out serial data
19.7 Programming Conditi ons
(operating conditions: Tamb = -40 to +125°C, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation) unless
otherwise noted)
P
Pa
ar
ra
am
me
et
te
er
r
S
Sy
ym
mb
bo
ol
l
M
Mi
in
n
T
Ty
yp
p
M
Ma
ax
x
U
Un
ni
it
t
N
No
ot
te
e
Programming enable time t Prog enable 2 µs
Time between rising edge at Prog
pin and rising edge of CSn
Write data start t Data in 2 µs
Write data valid t Data in valid 250 ns
Write data at the rising edge of
CLKPROG
Load programming data t Load PROG 3 µs
Rise time of VPROG before CLK PROG t
PrgR 0 µs
Hold time of VPROG after CLK PROG t
PrgH 0 5 µs
Write data – programming CLK PROG CLK PROG 250 kHz
CLK pulse width t PROG 1.8 2 2.2 µs During programming; 16 clock cycles
Hold time of Vprog after
programming
t PROG
finished
2 µs
Programmed data is available after
next power-on
Programming voltage V PROG 7.3 7.4 7.5 V Must be switched off after zapping
Programming voltage off level V ProgOff 0 1 V Line must be discharged to this level
Programming current I PROG 130 mA During programming
Analog read CLK CLKAread
100 kHz Analog readback mode
Programmed zener voltage (log.1) Vprogrammed
100 mV
Unprogrammed zener voltage (log. 0) Vunprogrammed 1
V
VRef-VPROG during analog readback
mode (see 13)
AS5043 Programmable 360° Magnetic Angle Encoder
Revision 1.6, 3-Oct-06 www.austriamicrosystems.com Page 25 of 26
20 Package Drawings and Markings
16-Lead Shrink Small Outline Package SSOP-16
Dimensions
mm inch
Symbol Min Typ Max Min Typ Max
A
1.73 1.86 1.99 .068 .073
.078
A
1 0.05 0.13 0.21 .002 .005
.008
A
2 1.68 1.73 1.78 .066 .068
.070
b 0.25 0.315 0.38 .010 .012
.015
c 0.09 - 0.20 .004 - .008
D 6.07 6.20 6.33 .239 .244
.249
E 7.65 7.8 7.9 .301 .307
.311
E1 5.2 5.3 5.38 .205 .209
.212
e 0.65 .0256
K 0° - 8° 0° - 8°
L 0.63 0.75 0.95 .025 .030
.037
21 Packing Options
Delivery: Tape and Reel (1 reel = 2000 devices)
Tubes (1 box = 100 tubes á 77 devices)
Order # AS5043ASSU for delivery in tubes
Order # AS5043ASST for delivery in tape and reel
A
YWWIZZ
AS5043
1.1.1 Marking: AYWWIZZ
A: Pb-Free Identifier
Y: Last Digit of Manufacturing Year
WW: Manufacturing Week
I: Plant Identifier
ZZ: Traceability Code
JEDEC Package Outline Standard:
MO - 150 AC
Thermal Resistance Rth(j-a):
typ. 151 K/W in still air, soldered on PCB
IC’s marked with a white dot or the
letters “ES” denote Engineering samples
AS5043 Programmable 360° Magnetic Angle Encoder
Revision 1.6, 3-Oct-06 www.austriamicrosystems.com Page 26 of 26
22 Recommended PCB Footprint:
Recommended Footprint Data
mm
inch
A
9.02
0.355
B
6.16
0.242
C
0.46
0.018
D
0.65
0.025
E
5.01
0.197
23 Revision History
Revision Date Description
1.6 Oct.3, 2006 Update DAC parameters (19.3.5), definition of magnet thickness
1.5 Aug.14, 2006
Update Isupp (19.2), Boff (19.4), tDOvalid (19.6), Ordering options (21)
1.4 Apr. 04, 2006 Update Programming Sequence Figure 11; Update Prog. Conditions 19.7
Include new OTP feature: permanent enabling of analog output (see 11.1.2).
1.3 Sep. 27, 2005
Update added features for Date Codes A534xx and higher: 10%/90% clamp levels, def. OPAMP gain =
ext., r/y/g Field indicators, exit alignment mode by s/w, falling edge on analog response curve on 45°
and 90° modes, jitter-free transition 360°/0° in analog mode. Update prop. delay and Rth of IC package
1.2 April 11, 2005 Add description for Analog modes and Programming
1.1 Feb. 18.2005 Update pin assignment and operating modes
1.0 Dec. 7, 2004 initial revision
24 Contact
24.1 Headquarters
austriamicrosystems AG
A 8141 Schloss Premstätten, Austria
Phone: +43 3136 500 0 Fax: +43 3136 525 01
info@austriamicrosystems.com?subject=AS5043
www.austriamicrosystems.com
25 Copyright
Devices sold by austriamicrosystems are covered by the warranty and patent indemnification provisions appearing in its Term of
Sale. austriamicrosystems makes no warranty, express, statutory, implied, or by description regarding the information set forth
herein or regarding the freedom of the described devices from patent infringement. austriamicrosystems reserves the right to
change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is
necessary to check with austriamicrosystems for current information. This product is intended for use in normal commercial
applications.
Copyright © 2006 austriamicrosystems. Trademarks registered ®. All rights reserved. The material herein may not be
reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. To the best of
its knowledge, austriamicrosystems asserts that the information contained in this publication is accurate and correct. However,
austriamicrosystems shall not be liable to recipient or any third party for any damages, including but not limited to personal
injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential
damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No
obligation or liability to recipient or any third party shall arise or flow out of austriamicrosystems rendering of technical or other
services.
