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AS5145

Datasheet - Detailed Descr i p ti on

Figure 10. Daisy Chain Mode Data Transfer

8.2 Pulse Width Modulation (PWM) Output

The AS5145 provides a pulse width modulated output (PWM), whose duty cycle is proportional to the measured angle. For angle position 0 to

4094

Position =

(EQ 1)

Examples:

1. An angle position of 180° will generate a pulse width ton = 2049µs and a pause toff of 2049 µs resulting in Position = 2048 after the cal-

culation: 2049 * 4098 / (2049 + 2049) -1 = 2048

2. An angle position of 359.8° will generate a pulse width ton = 4095µs and a pause toff of 3 µs resulting in Position = 4094 after the cal-

culation: 4095 * 4098 / (4095 + 3) -1 = 4094

Exception:

1. An angle position of 359.9° will generate a pulse width ton = 4097µs and a pause toff of 1 µs resulting in Position = 4096 after the cal-

culation: 4097 * 4098 / (4097 + 1) -1 = 4096

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.

Figure 11. PWM Output Signal

CSn

CLK

DO

Angular Position Data

Status Bits

1

D9

D8

D7

D6

D5

D4

D3

D2

D1

D0 OCF COF LIN

Mag

INC

Mag

DEC

Even

PAR

8

18

D

D11

1

2

3

D10 D9

Angular Position Data

1

2

D10

D11

t

on

4098

⋅

t

on

t

off

+

()

-------------------------

1

–

4098µs

4097µs

359.91 deg

(Pos 4095)

0 deg

(Pos 0)

Angle

1µs