AS5045

Data Sheet

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Revision 1.7

17 – 33

9.1

Changing the PWM Frequency

The PWM frequency of the AS5045 can be divided by two by setting a bit (PWMhalfEN) in the OTP register (see

chapter 11). With PWMhalfEN = 0 the PWM timing is as shown in Table 6:

Table 6.

PWM Signal Parameters (default mode)

Parameter

Symbol

Typ

Unit

Note

PWM frequency

244

Hz

Signal period: 4097µs

MIN pulse width

1

µs

- Position 0d

- Angle 0 deg

MAX pulse width

4096

µs

- Position 4095d

- Angle 359.91 deg

When PWMhalfEN = 1, the PWM timing is as shown in Table 7:

Table 7.

PWM Signal Parameters with Half Frequency (OTP option)

Parameter

Symbol

Typ

Unit

Note

PWM frequency

122

Hz

Signal period: 8194µs

MIN pulse width

2

µs

- Position 0d

- Angle 0 deg

MAX pulse width

8192

µs

- Position 4095d

- Angle 359.91 deg

10 Analog Output

An analog output can be generated by averaging the PWM signal, using an external active or passive low pass filter.

The analog output voltage is proportional to the angle: 0°= 0V; 360° = VDD5V.

Using this method, the AS5045 can be used as direct replacement of potentiometers.

Figure 9. Simple 2

Figure 9

shows an example of a simple passive low pass filter to generate the analog output.

R1, R2

≥ 4k7

C1, C2

≥ 1µF / 6V

R1 should be

≥4k7 to avoid loading of the PWM output. Larger values of Rx and Cx will provide better filtering and

less ripple, but will also slow down the response time.