www.austriamicrosystems.com/AS5140H
Revision 1.4
5 - 37
AS5140H
Data Sheet - Pin Assignments
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. 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:
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.
Note:   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 LSBs.
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 page 21). This pin is also used as digital input to shift serial data through the device in Daisy Chain configuration, (see page 14).
- 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 page
22) and programming mode (see page 19).
- 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 1祍
pulse width per step (1祍 to 1024祍 over a full turn). By using an external low pass filter, the digital PWM signal is converted into an ana-
log voltage, allowing a direct replacement of potentiometers.
PWM_LSB
12
Pulse Width Modulation of approx. 1kHz; LSB in Mode3.x
NC
13
For internal use. Must be left unconnected.
NC
14
For internal use. Must be left unconnected.
VDD3V3
15
3V-Regulator Output (see Figure 17)
VDD5V
16
Positive Supply Voltage 5V
Table 2. Pin Assignment for Different Incremental Output Modes
Output Mode
Pin 3
Pin 4
Pin 6
Pin 12
1.x: Quadrature
A
B
Index
PWM
2.x: Step/direction
LSB
Direction
Index
PWM
3.x: Commutation
U
V
W
LSB
Table 1. Pin Descriptions
Pin Name
Pin Number
Description