1 2 - B i t P r o g r a m m a b l e M a g n e t i c R o ta r y E n c o d e r
D a ta S he e t
1 General Description
The AS5145 is a contact less magnetic rotary encoder
for accurate angular measurement over a full turn of 360
degrees.
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 0.0879º = 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 AS5145 to
operate at either 3.3V or 5V supplies.
Figure 1. Arrangement of AS5145 and Magnet
2 Key Features
Contact less high resolution rotational position
encoding over a full turn of 360 degrees
Two digital 12 bit absolute outputs:
- Serial interface
- Pulse width modulated (PWM) output
Three incremental outputs
Quadrature A/B (10 or 12-bit) and Index output
signal (pre-programmed versions available AS5145-
I10/AS5145-I12)
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 AS5145
devices using Daisy Chain mode
Tolerant to magnet misalignment and gap variations
Wide temperature range: - 40ºC to +150ºC
Fully automotive qualified to AEC-Q100, grade 0
Small Pb-free package: SSOP 16 (5.3mm x 6.2mm)
3 Applications
The device is ideal for industrial applications like
contactless rotary position sensing and robotics;
automotive applications like steering wheel position
sensing, transmission gearbox encoder, head light
position control, torque sensing, valve position sensing
and replacement of high end potentiometers.
VDD3V3
MagINCn
MagDECn
PWM
Interface
Sin
Hall Array
&
Front end
Amplifier
Cos
DSP
Mag
Ang
Absolute
Interface
(SSI)
DO
CSn
CLK
OTP
Register
Mux
Mode_Index
Incremental
Interface
PDIO
DTEST1_A
DTEST2_B
PWM
Figure 2. Block Diagram
VDD5V
LDO 3.3V
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Revision 1.6
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AS5145
Data Sheet - A p p l i c a t i o n s
Contents
1 General Description ...............................................................................................................................1
2 Key Features ...........................................................................................................................................1
6.1 Magnetic Input Specification..............................................................................................................................8
6.2 System Specifications .......................................................................................................................................9
8.2.1 Changing the PWM Frequency .............................................................................................................18
8.3 Analog Output .................................................................................................................................................19
9 Application Information .......................................................................................................................20
9.1 Programming the AS5145 ...............................................................................................................................20
9.1.1
9.1.2
9.1.3
9.1.4
9.1.5
9.1.6
9.1.7
Zero Position Programming ..................................................................................................................20
9.7.7 Accuracy over Temperature ..................................................................................................................31
9.8 AS5145 Differences to AS5045.......................................................................................................................32
10 Package Drawings and Markings...................................................................................................... 33
10.2 Revision History ............................................................................................................................................35