Datasheet AS5045 Datasheet (AUSTRIA MICRO SYSTEMS)

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

AS5045
12 BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

1 General Description

The AS5045 is a contactless magnetic rotary encoder for
accurate angular measurement over a full turn of 360°.
It is a system-on-chip, combining integrated Hall
elements, analog front end and digital signal processing
in a single device.

To measure the angle, only a simple two-pole magnet,
rotating over the center of the chip, is required. The
magnet may be placed above or below the IC.

The absolute angle measurement provides instant
indication of the magnet’s angular position with a
resolution of 0.0879° = 4096 positions per revolution.
This digital data is available as a serial bit stream and as
a PWM signal.

An internal voltage regulator allows the AS5045 to
operate at either 3.3 V or 5 V supplies

1.2 Key Features

- Contactless high resolution rotational position

encoding over a full turn of 360 degrees

- Two digital 12bit absolute outputs:

- Serial interface and

- Pulse width modulated (PWM) output

- User programmable zero position

- Failure detection mode for magnet placement

monitoring and loss of power supply

- “red-yellow-green” indicators display placement of

magnet in Z-axis

- Serial read-out of multiple interconnected AS5045

devices using Daisy Chain mode

- Tolerant to magnet misalignment and airgap

variations

- Wide temperature range: - 40°C to + 125°C

- Small Pb-free package: SSOP 16 (5.3mm x 6.2mm)

DATA SHEET

Figure 1: Typical arrangement of AS5045 and magnet

1.1 Benefits

- Complete system-on-chip

- Flexible system solution provides absolute and PWM

outputs simultaneously

- Ideal for applications in harsh environments due to

contactless position sensing

- No calibration required

1.3 Applications

- Industrial applications:

- Contactless rotary position sensing

- Robotics

- Automotive applications:

- Steering wheel position sensing

- Transmission gearbox encoder

- Headlight position control

- Torque sensing

- Valve position sensing

- Replacement of high end potentiometers

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 1 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

2 Pin Configuration

MagINCn

MagDECn

NC

NC

NC

Mode

VSS

Prog_DI

2

3

4

5

6

7

8

Figure 2: Pin configuration SSOP16

2.1 Pin Description

Table 1 shows the description of each pin of the standard
SSOP16 package (Shrink Small Outline Package, 16
leads, body size: 5.3mm x 6.2mmm; see Figure 2).

Pins 7, 15 and 16 are supply pins, pins 3, 4, 5, 6, 13 and
14 are for internal use and must not be connected.

Pins 1 and 2 are the magnetic field change indicators,
MagINCn and MagDECn (magnetic field strength
increase or decrease through variation of the distance
between the magnet and the device). These outputs can
be used to detect the valid magnetic field range.
Furthermore those indicators can also be used for
contact-less push-button functionality.

Pin 6 Mode allows switching between filtered (slow) and
unfiltered (fast mode). See section 4.

Pin Symbol Type Description

1 MagINCn DO_OD

2 MagDECn DO_OD

3 NC - Must be left unconnected

4 NC - Must be left unconnected

5 NC - Must be left unconnected

6 Mode -

7 VSS S Negative Supply Voltage (GND)

8 Prog_DI DI_PD

9 DO DO_T

10 CLK

DI,
ST

161

15

14

13

12

AS5045

11

10

VDD5V

VDD3V3

NC

NC

PWM

CSn

CLK

9

DO

Magnet Field Magnitude INCrease;
active low, indicates a distance
reduction between the magnet and
the device surface. See Table 5

Magnet Field Magnitude DECrease;
active low, indicates a distance
increase between the device and the
magnet. See Table 5

Select between slow (open, low:
VSS) and fast (high) mode. Internal
pull-down resistor.

OTP Programming Input and Data
Input for Daisy Chain mode. Internal
pull-down resistor (~74kΩ).
Connect to VSS if not used

Data Output of
Synchronous Serial Interface

Clock Input of
Synchronous Serial Interface;
Schmitt-Trigger input

Pin Symbol Type Description

11 CSn

12 PWM DO

13 NC - Must be left unconnected

14 NC - Must be left unconnected

15 VDD3V3 S

16 VDD5V S Positive Supply Voltage, 3.0 to 5.5 V

DO_OD digital output open drain S supply pin
DO digital output DI digital input
DI_PD digital input pull-down DO_T digital output /tri-state
DI_PU digital input pull-up ST Schmitt-Trigger input

DI_PU,
ST

Table 1: Pin description SSOP16

Chip Select, active low; Schmitt-

Trigger input, internal pull-up resistor
(~50kΩ)

Pulse Width Modulation of approx.
244Hz; 1µs/step
(opt. 122Hz; 2µs/step)

3V-Regulator Output, internally
regulated from VDD5V. Connect to
VDD5V for 3V supply voltage. Do not
load externally.

Pin 8 (Prog) is used to program the zero-position into the
OTP (see chapter 7.1).

This pin is also used as digital input to shift serial data
through the device in Daisy Chain configuration,
(see page 6).

Pin 11 Chip Select (CSn; active low) selects a device
within a network of AS5045 encoders and initiates serial
data transfer. A logic high at CSn puts the data output
pin (DO) to tri-state and terminates serial data transfer.
This pin is also used for alignment mode (Figure 13) and
programming mode (Figure 9).

Pin 12 allows a single wire output of the 10-bit absolute
position value. The value is encoded into a pulse width
modulated signal with 1µs pulse width per step (1µs to
4096µs over a full turn). By using an external low pass
filter, the digital PWM signal is converted into an analog
voltage, making a direct replacement of potentiometers
possible.

3 Functional Description

The AS5045 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 around the
center of the device and deliver a voltage representation
of the magnetic field at the surface of the IC.

Through Sigma-Delta Analog / Digital Conversion and
Digital Signal-Processing (DSP) algorithms, the AS5045
provides accurate high-resolution absolute angular
position information. For this purpose a Coordinate

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 2 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

Rotation Digital Computer (CORDIC) calculates the angle
and the magnitude of the Hall array signals.

The DSP is also used to provide digital information at the
outputs MagINCn and MagDECn that indicate
movements of the used magnet towards or away from the
device’s surface.

A small low cost diametrically magnetized (two-pole)
standard magnet provides the angular position
information (see Figure 16).

The AS5045 senses the orientation of the magnetic field
and calculates a 12-bit binary code. This code can be
accessed via a Synchronous Serial Interface (SSI). In
addition, an absolute angular representation is given by a
Pulse Width Modulated signal at pin 12 (PWM). This
PWM signal output also allows the generation of a direct
proportional analogue voltage, by using an external Low­Pass-Filter.

The AS5045 is tolerant to magnet misalignment and
magnetic stray fields due to differential measurement
technique and Hall sensor conditioning circuitry.

Figure 3: AS5045 block diagram

4 Mode Input Pin

The mode input pin activates or deactivates an internal filter, that is used to reduce the analog output noise.

Activating the filter (Mode pin = LOW or open) provides a reduced output noise of 0.03° rms. At the same time, the output
delay is increased to 384µs. This mode is recommended for high precision, low speed applications.

Deactivating the filter (Mode pin = HIGH) reduces the output delay to 96µs and provides an output noise of 0.06° rms. This
mode is recommended for higher speed applications.

Switching the Mode pin affects the following parameters:

Parameter slow mode (Mode = low or open) fast mode (Mode = high, VDD5V)

sampling rate 2.61 kHz (384 µs) 10.42 kHz (96µs)

transition noise (1 sigma)

output delay 384µs 96µs

max. speed @ 4096 samples/rev.

max. speed @ 1024 samples/rev.

max. speed @ 256 samples/rev.

max. speed @ 64 samples/rev.

≤ 0.03° rms ≤ 0.06° rms

38 rpm

153 rpm

610 rpm

2441 rpm

153 rpm

610 rpm

2441 rpm

9766 rpm

Table 2: Slow and fast mode parameters

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 3 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

12-bit Absolute Angular Position Output

4.1 Synchronous Serial Interface (SSI)

CSn

T

CLK/2

D111D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 OCF COF LIN

t

DO valid

Figure 4: Synchronous serial interface with absolute angular position data

CLK

DO

t

DO active

t

CLK FE

t

CLK FE

t

CSn

1188

Mag

Mag
DEC

Even
PAR

t

DO Tristate

INC

Status BitsAngular Position Data

D11

If CSn changes to logic low, Data Out (DO) will change from
high impedance (tri-state) to logic high and the read-out will
be initiated.

 After a minimum time t

data is latched into the

CLK FE,

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 18 bits, the first 12 bits are

the angular information D[11:0], the subsequent 6 bits
contain system information, about the validity of data
such as OCF, COF, LIN, Parity and Magnetic Field
status (increase/decrease) .

 A subsequent measurement is initiated by a “high”

pulse at CSn with a minimum duration of t

CSn.

4.1.1 Data Content
D11:D0 absolute angular position data (MSB is clocked

out first)
OCF (Offset Compensation Finished), logic high

indicates the finished Offset Compensation Algorithm
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 can contain invalid data. This warning may be
resolved by bringing the magnet within the X-Y-Z
tolerance limits.

Even Parity bit for transmission error detection of bits
1…17 (D11…D0, OCF, COF, LIN, MagINC, MagDEC)

Placing the magnet above the chip, angular values increase in clockwise direction by default.

Data D11:D0 is valid, when the status bits have the following configurations:

OCF COF LIN

Mag
INC

Mag
DEC

Parity

0 0

1 0 0

0 1

1 0

even

checksum of

bits 1:15

1*) 1*)

Table 3: Status bit outputs

*) MagInc=MagDec=1 is only recommended in YELLOW mode (see Table 5)

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 4 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

4.1.2 Z-axis Range Indication (Push Button Feature, Red/Yellow/Green Indicator)

The AS5045 provides several options of detecting
movement and distance of the magnet in the Z-direction.
Signal indicators MagINCn and MagDECn are available both

serial data stream (see Figure 4). Additionally, an OTP
programming option is available with bit MagCompEn (see
Figure 9) that enables additional features:

as hardware pins (pins #1 and 2) and as status bits in the

In the default state, the status bits MagINC, MagDec
and pins MagINCn, MagDECn have the following function:

Status bits Hardware pins OTP: Mag CompEn = 0 (default)

Mag

Table 4: Magnetic field strength variation indicator

INC

Mag
DEC

Mag
INCn

Mag

DECn

0 0 Off Off

0 1 Off On

1 0 On Off

1 1 On On

Description

No distance change
Magnetic input field OK (in range, ~45…75mT)

Distance increase; pull-function. This state is dynamic and only active while the magnet is
moving away from the chip.

Distance decrease; push- function. This state is dynamic and only active while the magnet is
moving towards the chip.

Magnetic input field invalid – out of recommended range:
too large, too small (missing magnet)

When bit MagCompEn is programmed in the OTP, the function of status bits MagINC, MagDec
and pins MagINCn, MagDECn is changed to the following function:

Status bits Hardware pins OTP: Mag CompEn = 1 (red-yellow-green programming option)

Mag

INC

Mag
DEC

LIN

0 0 0 Off Off

1 1 0 On Off

1 1 1 On On

Mag

INCn

Mag

DECn

Description

No distance change
Magnetic input field OK ( GREEN range, ~45…75mT)

YELLOW range: magnetic field is ~ 25…45mT or ~75…135mT. The AS5045 may
still be operated in this range, but with slightly reduced accuracy.

RED range: magnetic field is ~<25mT or >~135mT. It is still possible to operate the
AS5045 in the red range, but not recommended.

All other combinations n/a n/a Not available

Table 5: Magnetic field strength red-yellow-green indicator (OTP option)

Note: Pin 1 (MagINCn) and pin 2 (MagDECn) are active low via open drain output and require an external pull-up resistor. If
the magnetic field is in range, both outputs are turned off.

The two pins may also be combined with a single pull-up resistor. In this case, the signal is high when the magnetic field is
in range. It is low in all other cases (see Table 4 and Table 5).

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 5 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

A

A

A

4.2 Daisy Chain Mode

The Daisy Chain mode allows connection of several AS5045’s in series, while still keeping just one digital input for data
transfer (see “Data IN” in Figure 5 below). 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 * (18+1) bits:

e.g. 38 bit for two devices, 57 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 (D11), etc…
(see Figure 6)

CSn

CLK

DO

t

DO active

t

CLK FE

µC

Data IN

S5045

1st Device

ProgDO

CLKCSn

S5045

2nd Device

S5045

last Device

ProgDO

CLKCSn

CLK

CSn

Figure 5: Daisy Chain hardware configuration

T

CLK/2

D111D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 OCF COF LIN

t

DO valid

1st Device 2nd Device

ProgDO

CLK CSn

D188

123

Mag

Mag
DEC

Even
PAR

Angular Position Data

INC

Status BitsAngular Position Data

D11

D10

D9

Figure 6: Daisy Chain mode data transfer

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 6 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

R1

5 Pulse Width Modulation (PWM)

Output

The AS5045 provides a pulse width modulated output
(PWM), whose duty cycle is proportional to the measured
angle:

4097

⋅

t

on

Position

=

()

+

tt

The PWM frequency is internally trimmed to an accuracy

of ±5% (±10% over full temperature range). This
tolerance can be cancelled by measuring the complete
duty cycle as shown above.

Angle

PW

0 deg
(Pos 0)

1µs

359.91 deg
(Pos 4095)

offon

MIN

1

−

4097µs

PW

MAX

When PWMhalfEN = 1, the PWM timing is as shown in
Table 7:

Parameter Symbol Typ Unit Note

PWM

frequency

MIN pulse

width

MAX pulse

width

Table 7: PWM signal parameters with half frequency (OTP option)

PW

PW

f

PWM

122 Hz

MIN

8192 µs

MAX

2 µs

Signal period:
4097µs

- Position 0d

- Angle 0 deg

- Position 4095d

- Angle 359,91 deg

6 Analog Output

An analog output can be generated by averaging the
PWM signal, using an external active or passive lowpass
filter. The analog output voltage is proportional to the
angle: 0°= 0V; 360° = VDD5V.

Using this method, the AS5045 can be used as direct
replacement of potentiometers.

Pin12

R2

analog out

4096µs

1/f

PWM

Figure 7: PWM output signal

5.1 Changing the PWM Frequency

The PWM frequency of the AS5045 can be divided by two
by setting a bit (PWMhalfEN) in the OTP register (see
chapter 7). With PWMhalfEN = 0 the PWM timing is as
shown in Table 6:

Parameter Symbol Typ Unit Note

PWM

frequency

MIN pulse

width

MAX pulse

width

Table 6: PWM signal parameters (defaul t mode)

PW

PW

f

PWM

MIN

4096 µs

MAX

244 Hz

1 µs

Signal period:
4097µs

- Position 0d

- Angle 0 deg

- Position 4095d

- Angle 359,91 deg

PWM

C1

C2

VDD

Pin7

0V

0°

360°

VSS

Figure 8: Simple 2nd order passive RC lowpass filte r

Figure 8 shows an example of a simple passive lowpass
filter to generate the analog output.

R1,R2 ≥ 4k7 C1,C2 ≥ 1µF / 6V

R1 should be ≥4k7 to avoid loading of the PWM output.
Larger values of Rx and Cx will provide better filtering
and less ripple, but will also slow down the response
time.

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 7 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

7 Programming the AS5045

After power-on, programming the AS5045 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 Mode
setting bits. Data must be valid at the rising edge of CLK
(see Figure 9).

After writing the data into the OTP register it can be
permanently programmed by rising the Prog pin to the
programming voltage V
be applied to program the fuses (Figure 10). To exit the
programming mode, the chip must be reset by a power­on-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 V
Prog should not exceed 50mm (2 inches). To suppress
eventual voltage spikes, a 10nF ceramic capacitor should
be connected close to pins VPROG and VSS. This
capacitor is only required for programming, it is not
required for normal operation. The clock timing t
be selected at a proper rate to ensure that the signal
Prog is stable at the rising edge of CLK (see Figure 9).
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 15.2).

To compensate for the voltage drop across the V
switching transistor, the applied programming voltage
may be set slightly higher (7.5 - 8.0V, see Figure 11).

OTP Register Contents:
CCW Counter Clockwise Bit

ccw=0 – angular value increases in clockwise direction
ccw=1 – angular value increases in counterclockwise
direction

Z [11:0]: Programmable Zero Position
PWM dis: Disable PWM output
MagCompEn: when set, activates LIN alarm both

when magnetic field is too high and
too low (see Table 5).

PWMhalfEn: when set, PWM frequency is 122Hz or

2µs / step (when PWMhalfEN = 0,
PWM frequency is 244Hz, 1µs / step)

. 16 CLK pulses (t

PROG

switching transistor and pin

PROG

PROG

) must

must

clk

PROG

7.1 Zero Position Programming

Zero position programming is an OTP option that
simplifies assembly of a system, as the magnet does not
need to be manually adjusted to the mechanical zero
position. Once the assembly is completed, the
mechanical and electrical zero positions can be matched
by software. Any position within a full turn can be defined
as the permanent new zero position.

For zero position programming, the magnet is turned to
the mechanical zero position (e.g. the “off”-position of a
rotary switch) and the actual angular value is read.

This value is written into the OTP register bits Z11:Z0
(see Figure 9) and programmed as described in
section 7.

Note: The zero position value may also be modified
before programming, e.g. to program an electrical zero
position that is 180° (half turn) from the mechanical zero
position, just add 2048 to the value read at the
mechanical zero position and program the new value into
the OTP register.

7.2 Repeated OTP Programming

Although a single AS5045 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.

7.3 Non-permanent Programming

It is also possible to re-configure the AS5045 in a non­permanent way by overwriting the OTP register.

This procedure is essentially a “Write Data” sequence
(see Figure 9) 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 14.6).

See Application Note AN5000-20 for further information.

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 8 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

CSn

t

Datain

Prog

CCW Z11 Z10 Z9 Z8 Z7 Z6 Z5 Z4 Z3 Z2 Z1 Z0

PWM

dis

Mag

Comp

EN

PWM

half

EN

CLK

CLK

PROG

t

Prog enable

CSn

Prog

PROG

1 168

t

t

Dat ain valid

clk

see text

Zero Position

Figure 9: Programming access – write data (section of Figure 10)

Write Data Power OffProgramming Mode

Data

116

t

t

Load PROG

t

PrgR

PrgH

t

PROG

PWM and status

bit m odes

7.5V
VDD

V

0V

t

PROG finished

ProgOff

MagINCn

2

MagDECn

3

NC

4

NC

5

NC

6

Mode

7

VSS

8

Prog_DI

10n

Cap only required for
OTP programming

Figure 10: Complete programming sequence

AS5045 Demoboard

For programming,

IC1

161

VDD5V

15

VDD3V3

14

NC

13

NC

12

PWM

11

CSn

10

CLK

9

DO

AS5045

Figure 11: OTP programming connection of AS5045 (shown with AS5045 demoboard)

1µF

keep these 6 wires

as short as possible!

max. length = 2 inches (5cm)

+

22k
*see Text

7

PROG

6

CSN

5

DO

4

CLK

3

5VUSB

2

VDD3V3

1

VSS

µC

GND

3V3

USB

connect to USB
interface on PC

VPROG

3
2

+

1

10µF

VSS

7.5 … 8.0V
only required for
OTP programming

GND

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 9 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

7.4 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 bit, 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 AS5045 in Analog Readback Mode, a digital
sequence must be applied to pins CSn, PROG and CLK
as shown in Figure 12. The digital level for this pin
depends on the supply configuration (3.3V or 5V; see
section 0).

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 12).

The following falling slope of CSn changes pin PROG to
an analog output, providing a reference voltage V
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 9: Md0-MD1-Div0,Div1-Indx-Z0…Z11, ccw).

If a capacitor is connected to pin PROG, it should be
removed during analog readback mode to allow a fast
readout rate. If the capacitor is not removed the analog
voltage will take longer to stabilize due to the additional
capacitance.

The measured analog voltage for each bit must be
subtracted from the previously measured V

, and the

ref

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 18

th

clock (after reading bit “ccw”), the chip

must be reset by disconnecting the power supply.

, that

ref

CSn

PROG

CLK

ProgEN

t

LoadProg

OutpEN

V

Internal

test bit

digital

ref

Prog changes to Output

Analog Readback Data at PROG

V

programmed

Mag

PWM

halfEN

116

PWM

Comp

EN

Figure 12: OTP register analog re ad

Z0

V

Dis

CLK

unprogrammed

Aread

Z8Z7

Z11

Z10Z9

Power-on­Reset;
turn off
supply

CCW

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 10 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

8 Alignment Mode

The alignment mode simplifies centering the magnet over
the center of the chip to gain maximum accuracy.

Alignment mode can be enabled with the falling edge of
CSn while Prog = logic high (Figure 13). The Data bits
D9-D0 of the SSI change to a 12-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 128 over a full turn.
The MagINCn and MagDECn indicators will be = 1 when
the alignment mode reading is < 128. At the same time,
both hardware pins MagINCn (#1) and MagDECn (#2) will
be pulled to VSS. A properly aligned magnet will
therefore produce a MagINCn = MagDECn = 1 signal
throughout a full 360° turn of the magnet.

Stronger magnets or short gaps between magnet and IC
may show values larger than 128. 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 Alignment mode can be reset to normal operation by
a power-on-reset (disconnect / re-connect power supply)
or by a falling edge on CSn with Prog = low.

For 3.3V operation, the LDO must be bypassed by
connecting VDD3V3 with VDD5V (see Figure 15).

For 5V operation, the 5V supply is connected to pin
VDD5V, while VDD3V3 (LDO output) must be buffered by
a 1...10µF capacitor, which is supposed to be placed
close to the supply pin (see Figure 15).

The VDD3V3 output is intended for internal use only It
must not be loaded with an external load.

The output voltage of the digital interface I/O’s
corresponds to the voltage at pin VDD5V, as the I/O
buffers are supplied from this pin (see Figure

15).

5V Operation

1...10µF

100n

VDD5V

4.5 - 5.5V

VSS

VDD3V3

LDO

Internal
VDD

I
N
T
E
R
F
A
C
E

DO

PWM

CLK

CSn

Prog

Prog

CSn

AlignMode enable

2µs

2µs

min.

min.

Figure 13: Enabling the alignment mode

Read-out

via SSI

Prog

Read-out

via SSI

CSn

exit AlignMode

Figure 14: Exiting alignment mode

9 3.3V / 5V Operation

The AS5045 operates either at 3.3V ±10% or at 5V
±10%. This is made possible by an internal 3.3V Low­Dropout (LDO) Voltage regulator. The internal supply
voltage is always taken from the output of the LDO,
meaning that the internal blocks are always operating at

3.3V.

3.3V Operation

VDD3V3

VDD5V

3.0 - 3.6V

VSS

LDO

Internal
VDD

I
N
T
E
R
F
A
C
E

100n

DO

PWM

CLK

CSn

Prog

Figure 15: 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.

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 11 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

A

10 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 magnetic field strength perpendicular to the die
surface has to be in the range of ±45mT…±75mT (peak).

The magnet’s field strength should be verified using a
gauss-meter. The magnetic field B
along a concentric circle with a radius of 1.1mm (R1),
should be in the range of ±45mT…±75mT. (see Figure

16).

R1

Vertical field
component

Vertical field
component

Bv

(45…75mT)

0

360

Figure 16: Typical magnet (6x3mm) and magnetic field distribution

at a given distance,

v

typ. 6mm diameter

SN

Magnet axis

Magnet axis

R1 concentric circle;
radius 1.1mm

360

10.1 Physical Placement of the Magnet

The best linearity can be achieved by placing the center
of the magnet exactly over the defined center of the chip
as shown in the drawing below:

3.9 mm 3.9 mm

1

2.433 mm
Defined

center

R

d

2.433 mm

Figure 17: Defined chip center and magnet displacement radius

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.

The magnet may be placed below or above the device.
The distance should be chosen such that the magnetic
field on the die surface is within the specified limits (see
Figure 16). The typical distance “z” between the magnet
and the package surface is 0.5mm to 1.5mm, provided
the use of the recommended magnet material and
dimensions (6mm x 3mm). Larger distances are possible,
as long as the required magnetic field strength stays
within the defined limits.

However, a magnetic field outside the specified range
may still produce usable results, but the out-of-range
condition will be indicated by MagINCn (pin 1) and
MagDECn (pin 2), see Table 1.

rea of recommended maximum

magnet misalignment

SN

Package surfaceDie surface

z

0.576mm ± 0.1mm

1.282mm ± 0.15mm

Figure 18: Vertical placement of the magnet

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 12 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

A

±

11 Simulation Modeling

2.433 mm

±0.235mm

Figure 19: Arrangement of Hall sen sor array on chip (p rinciple)

S5045 die

3.9 mm

1

Radius of circular Hall sensor
array: 1.1mm radius

0.235mm

X1

Y1

X2

Y2

Center of die

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
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.

(X1-X2)

, B

) is ±75mT at the

(Y1-Y2)

With reference to Figure 19, a diametrically magnetized
permanent magnet is placed above or below the surface
of the AS5045. 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:

()

−

21

=Θ 5.0

arctan

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 AS5045. 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
(see Figure 19)

In order to neglect the influence of external disturbing
magnetic fields, a robust differential sampling and
ratiometric calculation algorithm has been implemented.

YY

()

−

21

XX

°±

12 Failure Diagnostics

The AS5045 also offers several diagnostic and failure
detection features:

12.1 Magnetic Field Strength Di agnosis

By software: the MagINC and MagDEC status bits will

both be high when the magnetic field is out of range.
By hardware: Pins #1 (MagINCn) and #2 (MagDECn) are

open-drain outputs and will both be turned on (= low with
external pull-up resistor) when the magnetic field is out
of range. If only one of the outputs are low, the magnet is
either moving towards the chip (MagINCn) or away from
the chip (MagDECn).

12.2 Power Supply Failure Detection

By software: If the power supply to the AS5045 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 MagINCn and MagDECn pins are
open drain outputs and require external pull-up resistors.
In normal operation, these pins are high ohmic and the
outputs are high (see Table 5). In a failure case, either
when the magnetic field is out of range of the power
supply is missing, these outputs will become low. To
ensure adequate low levels in case of a broken power

supply to the AS5045, the pull-up resistors (~10kΩ) from

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 13 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

0

1 55

each pin must be connected to the positive supply at pin
16 (VDD5V).

By hardware: PWM output: The PWM output is a
constant stream of pulses with 1kHz repetition frequency.
In case of power loss, these pulses are missing

13 Angular Output Tolerances

13.1 Accuracy

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 = (Err

±0.5 degrees @ 25°C (see Figure 21).

Misalignment of the magnet further reduces the
accuracy. Figure 20 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 21 is repeated and the accuracy
(Err

– Err

max

the Z-axis in the 3D-graph.

– Err

max

)/2 (e.g. 0.25° in Figure 21) is entered as

min

)/2 is specified as better than

min

Linearity Error over XY-misalignment [°]

6

5

4

°

3

2

1

0

1000

800

600

400

0

200

-200

y

-400

-800

-1000

-600

-800

-1000

-600

-400

-200

1000

800

600

400

200

0

x

Figure 20: Example of linearity error over XY misalig nment

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 this measurement was a cylindrical
NdFeB (Bomatec® BMN-35H) magnet with 6mm diameter
and 2.5mm in height.

Linearity error with centered magnet [degrees]

0.5

0.4

0.3

0.2

0.1

-0.1

-0.2

-0.3

-0.4

-0.5

Figure 21: Example of linearity error over 360°

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 14 of 23

109 163 217 271 325 379 433 487 541 595 649 703 757 811 865 919 973

Err

max

Err

min

transition noise

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

∗

=

13.2 Transition Noise

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)
and 0.03 degrees rms (1 sigma)

*1

in fast mode (pin MODE = high)

*1

in slow mode (pin

MODE = low or open).

This is 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 implementing 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.

 PWM interface:

If the PWM interface is used as an analog output by
adding a low pass filter, the transition noise can be
reduced by lowering the cutoff frequency of the
filter.
If the PWM interface is used as a digital interface
with a counter at the receiving side, the transition
noise may again be reduced by averaging of
readings.

*1

: statistically, 1 sigma represents 68.27% of readings,

3 sigma represents 99.73% of readings.

13.3 High Speed Operation

13.3.1 Sampling Rate

The AS5045 samples the angular value at a rate of 2.61k
(slow mode) or 10.42k (fast mode, selectable by pin
MODE) samples per second. Consequently, the absolute
outputs are updated each 384µs (96µs in fast mode).
At a stationary position of the magnet, the sampling rate
creates no additional error.

Absolute Mode

At a sampling rate of 2.6kHz/10.4kHz, the number of
samples (n) per turn for a magnet rotating at high speed
can be calculated by

n

eslow

mod

n

efast

mod

60

=

⋅

60

=

⋅

384

96

srpm

μ

srpm

μ

The upper speed limit in slow mode is ~6.000rpm and
~30.000rpm in fast mode. The only restriction at high
speed is that there will be fewer samples per revolution
as the speed increases (see Table 2).

Regardless of the rotational speed, the absolute angular
value is always sampled at the highest resolution of 12
bit.

13.4 Propagation Delays

The propagation delay is the delay between the time that
the sample is taken until it is converted and available as
angular data. This delay is 96µs in fast mode and 384µs
in slow mode.

Using the SSI interface for absolute data transmission,
an additional delay must be considered, caused by the
asynchronous sampling (0 … 1/f
takes the external control unit to read and process the
angular data from the chip (maximum clock rate = 1MHz,
number of bits per reading = 18).

13.4.1 Angular Error Caused by Propagation Delay

A rotating magnet will cause an angular error caused by
the output propagation delay.
This error increases linearly with speed:

delayproprpme

sampling

,

.*6

where

e

= angular error [°]

sampling

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 AS5045.

) and the time it

sample

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 15 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

13.5 Internal Timing Tolerance

The AS5045 does not require an external ceramic
resonator or quartz. All internal clock timings for the
AS5045 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 and the
pulse width of the PWM output:

 Absolute output; SSI interface:

A new angular value is updated every 400µs (typ.)

 PWM output:

A new angular value is updated every 400µs (typ.).
The PWM pulse timings T
same tolerance as the internal oscillator (see
above).
If only the PWM pulse width T
the angle, the resulting value also has this timing
tolerance.
However, this tolerance can be cancelled by
measuring both T
angle from the duty cycle (see section 5):

Position

=

and T

on

4097

⋅

t

on

()

+

tt

and T

on

on

and calculating the

off

1

−

offon

also have the

off

is used to measure

13.6 Temperature

13.6.1 Magnetic Temperatur e Coefficient

One of the major benefits of the AS5045 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 AS5045 automatically compensates for the varying
magnetic field strength over temperature. The magnet’s
temperature drift does not need to be considered, as the
AS5045 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 AS5045 can compensate for this temperature related
field strength change automatically, no user adjustment
is required.

13.7 Accuracy over 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.

13.7.1 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.
The only concern to the user is the width of the PWM
output pulse, which relates directly to the timing
tolerance of the internal oscillator. This influence
however can be cancelled by measuring the complete
PWM duty cycle instead of just the PWM pulse (see

13.5).

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 16 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

14 Electrical Characteristics

14.1 AS5045 Differences to AS5040

All parameters are according to AS5040 datasheet except for the parameters shown below:

Building Block AS5045 AS5040

Resolution 12bits, 0.088°/step. 10bits, 0.35°/step

Data length

read: 18bits
(12bits data + 6 bits status)
OTP write: 18 bits
(12bits zero position + 6 bits mode selection)

read: 16bits
(10bits data + 6 bits status)
OTP write: 16 bits
(10bits zero position + 6 bits mode
selection)

incremental encoder

Pins 1 and 2

Not used
Pin 3: not used
Pin 4:not used

MagINCn, MagDECn: same feature as AS5040,
additional OTP option for red-yellow-green
magnetic range

quadrature, step/direction and BLDC
motor commutation modes
Pin 3:incremental output A_LSB_U
Pin 4:incremental output B_DIR_V

MagINCn, MagDECn indicate in-range
or out-of-range magnetic field plus
movement of magnet in z-axis

Pin 6 MODE pin, switch between fast and slow mode Pin 6:Index output

Pin 12

sampling frequency

PWM output: frequency selectable by OTP:
1µs / step, 4096 steps per revolution, f=244Hz
2µs/ step, 4096 steps per revolution, f=122Hz

selectable by MODE input pin:

PWM output:
1µs / step, 1024 steps per revolution,
976Hz PWM frequency

fixed at 10kHz @10bit resolution

2.5kHz, 10kHz

Propagation delay

384µs (slow mode)

48µs

96µs (fast mode)

Transition noise
(rms; 1sigma)

0.03 degrees max. (slow mode)

0.06 degrees max. (fast mode)

0.12 degrees

OTP programming
options

zero position, rotational direction, PWM disable,
2 Magnetic Field indicator modes, 2 PWM

zero position, rotational direction,
incremental modes, index bit width

frequencies

14.2 Absolute Maximum Rati ngs (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

DC supply voltage at pin VDD5V VDD5V -0.3 7 V

DC supply voltage at pin VDD3V3 VDD3V3 5 V

Input pin voltage Vin -0.3 VDD5V +0.3 V Except VDD3V3

Input current (latchup immunity) I

Electrostatic discharge ESD ± 2 kV Norm: MIL 883 E method 3015

Storage temperature T

Body temperature (Lead-free
package)

Humidity non-condensing H 5 85 %

-100 100 mA Norm: JEDEC 78

scr

-55 125 °C Min – 67°F ; Max +257°F

strg

T

260 °C

Body

t=20 to 40s, Norm: IPC/JEDEC J-Std-020C

Lead finish 100% Sn “matte tin”

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 17 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

14.3 Operating Conditions

Parameter Symbol Min Typ Max Unit Note

Ambient temperature T

Supply current I

Supply voltage at pin VDD5V

Voltage regulator output voltage at pin VDD3V3

Supply voltage at pin VDD5V

Supply voltage at pin VDD3V3

-40 125 °C -40°F…+257°F

amb

16 21 mA

supp

VDD5V

VDD3V3

VDD5V

VDD3V3

4.5

3.0

3.0

3.0

5.0

3.3

3.3

3.3

5.5

3.6 V V

3.6

3.6 V V

5V Operation

3.3V Operation
(pin VDD5V and VDD3V3 connected)

14.4 DC Characteristics for Digital Inpu ts and Outputs

14.4.1 CMOS Schmitt-Trigger Inputs: CLK, CSn. (CSn = internal Pull-up)

(operating conditions: T

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 V

Input leakage current

Pull-up low level input current

= -40 to +125°C, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation) unless otherwise noted)

amb

1 V

Ion- VIoff

I

LEAK

I

iL

-1 1 CLK only

-30 -100

µA

µA

CSn only, VDD5V: 5.0V

14.4.2 CMOS / Program Input: Pro g

(operating conditions: T

= -40 to +125°C, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation) unless otherwise noted)

amb

Parameter Symbol Mi n Max Unit Note

High level input voltage VIH 0.7 * VDD5V VDD5V V

High level input voltage V

PROG

Low level input voltage VIL

See “programming

conditions”

0.3 *

VDD5V

V During programming

V

High level input current IiL 30 100 µA VDD5V: 5.5V

14.4.3 CMOS Output Open Drain: MagINCn, MagDECn

(operating conditions: T

= -40 to +125°C, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation) unless otherwise noted)

amb

Parameter Symbol Min Max Unit Note

Low level output voltage VOL VSS+0.4 V

Output current I

O

4

2

mA

VDD5V: 4.5V

VDD5V: 3V

Open drain leakage current IOZ 1 µA

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 18 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

14.4.4 CMOS Output: PWM

(operating conditions: T

= -40 to +125°C, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation) unless otherwise noted)

amb

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 I

O

4

2

mA

mA

VDD5V: 4.5V

VDD5V: 3V

14.4.5 Tristate CMOS Output: DO

(operating conditions: T

= -40 to +125°C, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation) unless otherwise noted)

amb

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 I

O

4 2 mA

mA

VDD5V: 4.5V

VDD5V: 3V

Tri-state leakage current IOZ 1 µA

14.5 Magnetic Input Specification

(operating conditions: T

Two-pole cylindrical diametrically magnetised source:

Parameter Symbol Min Typ Max Unit Note

Diameter d

Thickness t

Magnetic input field amplitude Bpk 45

Magnetic offset B

Field non-linearity 5 % Including offset gradient

Input frequency

(rotational speed of magnet)

Displacement radius Disp

Eccentricity Ecc 100 µm Eccentricity of magnet center to rotational axis

Recommended magnet
material and temperature drift

= -40 to +125°C, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation) unless otherwise noted)

amb

4 6 mm

mag

2.5 mm

mag

75 mT

Recommended magnet: Ø 6mm x 2.5mm for
cylindrical magnets

Required vertical component of the magnetic field
strength on the die’s surface, measured along a
concentric circle with a radius of 1.1mm

± 10 mT Constant magnetic stray field

off

2,44 146 rpm @ 4096 positions/rev.; fast mode

Hz

0,61

0.25 mm

36.6rpm @ 4096 positions/rev.; slow mode

Max. offset between defined device center and
magnet axis (see Figure 17)

NdFeB (Neodymium Iron Boron)

%/K

SmCo (Samarium Cobalt)

f

mag_abs

-0.12

-0.035

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 19 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

1

14.6 Electrical System Specifications

(operating conditions: T

Parameter Symb ol Min Typ Max Unit Note

Resolution RES 12 bit 0.088 deg

Integral non-linearity (optimum) INL

Integral non-linearity (optimum) INL

Integral non-linearity INL ± 1.4 deg

Differential non-linearity DNL ±0.044 deg 12bit, no missing codes

Transition noise TN

Power-on reset thresholds

On voltage; 300mV typ. hysteresis
Off voltage; 300mV typ. hysteresis

Power-up time t

absolute output : delay of ADC,
DSP and absolute interface

Internal sampling rate for
absolute output:

Internal sampling rate for
absolute output

Read-out frequency CLK 1 MHz Max. clock frequency to read out serial data

4095

= -40 to +125°C, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation) unless otherwise noted)

amb

± 0.5 deg

opt

Maximum error with respect to the best line fit.
Centered magnet without calibration, T

Maximum error with respect to the best line fit.

± 0.9 deg

temp

Centered magnet without calibration,

T

= -40 to +125°C

amb

Best line fit = (Err

max

– Err

) / 2

min

Over displacement tolerance with 6mm diameter

= -40 to +125°C

amb

V

on

V

off

PwrUp

1,37

1.08

2.2

1.9

magnet, without calibration, T

0.06 1 sigma, fast mode (MODE = 1)

0.03

Deg

RMS

1 sigma, slow mode (MODE=0 or open)

2.9

2.6

20 Fast mode (Mode = 1); Until status bit OCF = 1

80

V V DC supply voltage 3.3V (VDD3V3)

DC supply voltage 3.3V (VDD3V3)

ms

Slow mode (Mode = 0 or open); Until OCF = 1

96 Fast mode (MODE=1) System propagation delay

12bit code

α

t

delay

f

S

f

S

384

µs

2.48 2.61 2.74 T

2.35 2.61 2.87

kHz

9.90 10.42 10.94 T

9.38 10.42 11.46

kHz

Slow mode (MODE=0 or open)

= 25°C, slow mode (MODE=0 or open)

amb

T

= -40 to +125°C, slow mode (MODE=0 or open)

amb

= 25°C, fast mode (MODE = 1)

amb

T

= -40 to +125°C, : fast mode (MODE = 1)

amb

4095

=25 °C.

amb

Actual curve

2
1

0

TN

Ideal curve

DNL+1LSB

INL

0.09°

2048

2048

0

°

0

Figure 22: Integral and differential non-linearity (example)

80°

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

360

°

α

[degrees]

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 20 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

15 Timing Characteristics

Synchronous Serial Interface (SSI)

(operating conditions: T

Parameter Symb ol Min Typ Max Unit Note

Data output activated (logic
high)

First data shifted to output
register

Start of data output T

Data output valid t

Data output tristate t

Pulse width of CSn t

Read-out frequency f

15.1.1 Pulse Width Modulation Output

(operating conditions: T

= -40 to +125°C, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation) unless otherwise noted)

amb

t

DO active

t

CLK FE

CLK / 2

DO valid

DO tristate

CSn

CLK

= -40 to +125°C, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation) unless otherwise noted)

amb

100 ns

500 ns

500 ns Rising edge of CLK shifts out one bit at a time

357 375 394 ns

100 ns After the last bit DO changes back to “tristate”

500

ns

>0 1 MHz Clock frequency to read out serial data

Time between falling edge of CSn and data output
activated

Time between falling edge of CSn and first falling
edge of CLK

Time between rising edge of CLK and data output
valid

CSn = high; To initiate read-out of next angular
position

Parameter Symb ol Min Typ Max Unit Note

PWM frequency f

Minimum pulse width PW

Maximum pulse width PW

PWM

220 244 268

0.95 1 1.05 µs Position 0d; Angle 0 degree

MIN

3891 4096 4301 µs Position 4095d; Angle 359.91 degrees

MAX

232 244 256

Signal period = 4097µs ±5% at T

Hz

=4097µs ±10% at T

amb

Note: when OTP bit “PWMhalfEn” is set, the PWM pulse width PW is doubled (PWM frequency f

15.2 Programming Conditions

(operating conditions: T

Parameter Symbol Min Typ M ax Unit Note

Programming enable time t

Write data start t

Write data valid t

Load Programming data t

Rise time of V

Hold time of V

PROG

PROG

Write data – programming
CLK

PROG

CLK pulse width t

Hold time of Vprog after
programming

Programming voltage, pin PROG V

Programming voltage off level V

Programming current I

Analog Read CLK CLK

Programmed Zener Voltage (log.1) V

Unprogrammed Zener Voltage (log. 0) V

= -40 to +125°C, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation) unless otherwise noted)

amb

Time between rising edge at Prog
pin and rising edge of CSn

Write data at the rising edge of
CLK

ensure that V
rising edge of CLK

during programming; 16 clock
cycles

Programmed data is available after
next power-on

Line must be discharged to this
level

Analog Readback mode

V

Ref-VPROG

Readback mode (see 7.4)

V

before CLK

after CLK

t

PROG

t

PROG

t

Prog enable

Data in

Data in valid

Load PROG

0 µs

PrgR

0 5 µs

PrgH

CLK

PROG

1.8 2 2.2 µs

PROG

PROG finished

PROG

ProgOff

130 mA during programming

PROG

Aread

programmed

unprogrammed

2 µs

2 µs

250 ns

3 µs

250 kHz

2 µs

7.3 7.4 7.5 V Must be switched off after zapping

0 1 V

1

100 kHz

100 mV

= 25°C

amb

= -40 to +125°C

is divided by 2)

PWM

PROG

is stable with

PROG

during Analog

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 21 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

A

A

A

8°

16 Package Drawings and Markings

16-Lead Shrink Small Outline Package SSOP-16

AYWWIZZ
AS5045

Dimensions

Symbol

Min Typ Max Min Typ Max

1.73 1.86 1.99 .068 .073 .078

1 0.05 0.13 0.21 .002 .005 .008

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 -

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° -

L 0.63 0.75 0.95 .025 .030 .037

mm inch

.008

17 Ordering Information

Delivery: Tape and Reel (1 reel = 2000 devices)

Tubes (1 box = 100 tubes á 77 devices)

Order # AS5045ASSU for delivery in tubes
Order # AS5045ASST for delivery in tape and reel

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 R
typ. 151 K/W in still air, soldered on PCB

IC's marked with a white dot or the
letters "ES" denote Engineering Samples

th(j-a)

:

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 22 of 23

AS5045 12-BIT PROGRAMMABLE MAGNETIC ROTARY ENCODER

A

B

C

D

E

18 Recommended PCB Footprint:

Recommended Footprint Data

mm

9.02

6.16

0.46

0.65

5.01

19 Revision History

Revision Date Description

1.2 Oct. 03, 2006

1.1 Mar. 24, 2006

1.0 Dec. 7, 2004

Sep. 26, 2005

Jan. 11, 2006

Update description of Alignment Mode (8) and OTP programming (7.2, 7.3), Table 2, I
(14.5),

t

(15), definition of magnet thickness

DO valid

Added OTP prog. timing table 15.2, New Figure 10, Figure 11

Initial revision

Official release

Modify Figure 1, thermal resistance (Package Drawings and Markings)

20 Contact

inch

0.355

0.242

0.018

0.025

0.197

supp

(14.3), B

off

20.1 Headquarters

austriamicrosystems AG
A 8141 Schloss Premstätten, Austria

Phone: [phone]

Fax: [phone]

[e-mail]?subject=AS5045

www.austriamicrosystems.com

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 © 2005 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.

Revision 1.2, 03-Oct-06 www.austriamicrosystems.com Page 23 of 23