AS5171 datasheet(23/42 Pages) AMSCO

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ams Datasheet

Page 23

[v1-01] 2016-Feb-17

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AS5171 − Register Description

Extended Magnetic Input Range

The magnetic input field range can be boosted with the MFER

bit. The extended magnetic field allows increasing the

maximum air gap between the AS5171 and the magnet.

Analog Output (AS5171A)

The AS5171A provides a linear analog ratiometric output signal.

The output buffer features a push-pull analog output stage

which can be loaded with a pull-down or a pull-up resistor. The

output voltage represents the angular orientation of the

magnet above the AS5171A on a linear absolute scale and is

ratiometric to VDD.

PWM Output (AS5171B)

The AS5171B has a PWM output. With the DIGOS setting, the

PWM output stage can be programmed as a push-pull,

pull-down, or pull-up driver. The duty-cycle of each pulse is

proportional to the absolute angular position of the external

magnet.

The PWM signal consists of a frame of 4096 clock periods as

shown in Figure 30. The PWM frame begins with a certain

number of clocks high, defined by the CLMPL, which is followed

by the electrical angle information. The frame ends with a

certain number of clock pulses low, as defined by the CLMPH.

It is possible to invert the frame using the PWMINV setting.

Figure 30:

Pulse Width Modulation Frame

The PWMFR setting sets the duration of the PWM frequency.

The PWMSR setting chooses between fast and slow steps.

Mechanical angle

PWM period

CMPL

Electrical angle

CMPH

AS5171 Datasheet(PDF) 23 Page - ams AG