AS5140H
10-Bit 360º Programmable Magnetic
Rotary Encoder For High Ambient
Temperatures
General Description
The AS5140H is a contactless magnetic rotary encoder for
accurate angular measurement over a full turn of 360º and over
an extended ambient temperature range of -40ºC to 150ºC.
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 0.35º = 1024
positions per revolution. This digital data is available as a serial
bit stream and as a PWM signal. Furthermore, a
user-programmable incremental output is available.
An internal voltage regulator allows the AS5140H to operate at
either 3.3V or 5V supplies.
The AS5140H is pin-compatible to the AS5040; however it uses
low-voltage OTP programming cells with additional
programming options.
Ordering Information
and
Content Guide
appear at end of
datasheet.
Key Benefits & Features
The benefits and features of AS5140H, 10-Bit 360º
Programmable Magnetic Rotary Encoder For High Ambient
Temperatures are listed below:
Figure 1:
Added Value of Using AS5140H
Benefits
No mechanical wear
High resolution absolute position sensing
Features
Contactless high resolution rotational position encoding over a
full turn of 360º
Two digital 10-bit absolute outputs: Serial interface and Pulse
width modulated (PWM) output
Three incremental output modes: Quadrature A/B and Index
output signal, Step / Direction and Index output signal, 3-phase
commutation for brushless DC motors
User programmable zero / index position
Easy to use for motor control
Adjustable zero position
ams Datasheet
[v1-09] 2018-Feb-20
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AS5140H −
General Description
Benefits
Tolerant to magnet misalignment
Usable for high speed applications
Tolerant to airgap variations
Supports daisy chain application
Fitting to automotive applications
Operates up to 150°C ambient temperature
Features
Failure detection mode for magnet placement monitoring and
loss of power supply
Rotational speeds up to 10000 rpm
Pushbutton functionality detects movement of magnet in
Z-axis
Serial read-out of multiple interconnected AS5140H devices
using Daisy Chain mode
Fully automotive qualified to AEC-Q100, grade 0
Wide ambient temperature range: -40ºC to 150ºC
Applications
The AS5140H is an ideal solution for automotive applications
like engine compartment sensors, transmission gearbox
encoder, throttle valve position control and for industrial
applications like rotary sensors in high temperature
environment.
Block Diagram
The functional blocks of this device for reference are
shown below:
Figure 2:
AS5140H Block Diagram
LDO 3.3V
PWM
Interface
Hall Array
&
Frontend
Amplifier
DSP
Absolute
Interface
(SSI)
OTP
Register
Incremental
Interface
AS5140H
Programming
Parameters
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AS5140H −
Pin Assignment
Pin Assignment
Figure 3:
Pin Diagram (Top View)
AS5140H
Pin Description
The following figure 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 3).
Figure 4:
Pin Description
Pin Number
1
2
Pin Name
MagINCn
MagDECn
Description
Magnet Field Magnitude Increase.
Active low. Indicates a distance
reduction between the magnet and the device surface.
Magnet Field Magnitude Decrease.
Active low. Indicates a distance
increase between the device and the magnet.
Mode1.x:
Quadrature A channel
Mode2.x:
Least Significant Bit
Mode3.x:
U signal (phase1)
Mode1.x:
Quadrature B channel quarter period shift to channel A
Mode2.x:
Direction of Rotation
Mode3.x:
V signal (phase2)
For internal use. Must be left unconnected.
Mode1.x and Mode2.x:
Index signal indicates the absolute zero position
Mode3.x:
W signal (phase3)
3
A_LSB_U
4
5
6
B_Dir_V
NC
Index_ W
ams Datasheet
[v1-09] 2018-Feb-20
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AS5140H −
Pin Assignment
Pin Number
7
8
9
10
11
12
13
14
15
16
Pin Name
VSS
Prog
DO
CLK
CSn
PWM_LSB
NC
NC
VDD3V3
VDD5V
Description
Negative Supply Voltage (GND).
OTP Programming Input and Data Input for Daisy Chain mode.
Internal
pull-down resistor (~74kΩ). May be connected to VSS if programming is not
used.
Data Output
of Synchronous Serial Interface.
SSI Clock Input.
Schmitt-Trigger input.
Chip Select.
Active low; Schmitt-Trigger input, internal pull-up resistor
(~50kΩ) connect to VSS in incremental mode (see Incremental Power-up
Lock Option on
page 21)
Pulse Width Modulation of approx. 1kHz; LSB in Mode3.x
For internal use. Must be left unconnected.
For internal use. Must be left unconnected.
3V-Regulator Output (see
Figure 38)
Positive Supply Voltage 5V
Pin 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. Pins 3, 4 and 6 are the
incremental pulse output pins. The functionality of these pins
can be configured through programming the one-time
programmable (OTP) register.
Figure 5:
Pin Assignment for Different Incremental Output Modes
Output Mode
1.x: Quadrature
2.x: Step/direction
3.x: Commutation
Pin 3
A
LSB
U
Pin 4
B
Direction
V
Pin 6
Index
Index
W
Pin 12
PWM
PWM
LSB
Mode 1.x: Quadrature A/B Output
Represents the default quadrature A/B signal mode.
Mode 2.x: Step / Direction Output
Configures pin 3 to deliver up to 512 pulses (up to 1024 state
changes) per revolution. It is equivalent to the LSB (least
significant bit) of the absolute position value. Pin 4 provides the
information of the rotational direction.
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ams Datasheet
[v1-09] 2018-Feb-20
AS5140H −
Pin Assignment
Note(s):
Both modes (mode 1.x and mode 2.x) provide an index
signal (1 pulse/revolution) with an adjustable width of one LSB
or three LSB’s.
Mode 3.x: Brushless DC Motor Commutation Mode
In addition to the absolute encoder output over the SSI
interface, this mode provides commutation signals for
brushless DC motors with either one pole pair or two pole pair
rotors. The commutation signals are usually provided by 3
discrete Hall switches, which are no longer required, as the
AS5140H can fulfill two tasks in parallel:
absolute encoder + BLDC motor commutation.
In this mode,
• Pin 12 provides the LSB output instead of the PWM
(Pulse-Width-Modulation) signal.
• Pin 8 (Prog) is also used to program the different
incremental interface modes, the incremental resolution
and the zero position into the OTP (see
Incremental Mode
Programming).
This pin is also used as digital input to shift
serial data through the device in Daisy Chain
configuration, (see
Figure 24).
• Pin 11 Chip Select (CSn; active low) selects a device within
a network of AS5140H 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 (see
Alignment Mode)
and
programming mode (see
Programming the AS5140H).
• 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
1024μs over a full turn). By using an external low pass filter,
the digital PWM signal is converted into an analog voltage,
allowing a direct replacement of potentiometers.
ams Datasheet
[v1-09] 2018-Feb-20
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