PWM configuration features. STMicroelectronics STSW-ST25001

Tag main features UM2131

This feature is specific to ST25DV-PWM products.

Due to RF high-sensitivity levels, and because of the switching noise generated by a PWM output (by construction), the adjustment of different PWM parameters is proposed to improve the coexistence between the PWM interface and the RF interface:

 PWM output driver trimming

 PWM output coexistence with RF interface

Also available in the configuration, the PWM control access rights, to define R/W permissions and password for PWM control area.

Figure 43. PWM configuration features

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UM2131 Rev 6

UM2131 Tag main features

This feature is specific to ST25DV-PWM products.

PWM control enables to set PWM registers using the following main setting attributes:

 Disable/Enable PWM

 Period value

 Pulse-width value

Four profiles are available, with different level of detail and features:

 Normal : sets the duty cycle of each PWM with simple bar sliders (frequency already set through the Expert mode).

 Expert : provides detail setting for PWM attributes and corresponding registers values.

 Auto : demonstrator use case for autonomous changing of the duty cycle on the two channels, like one going up and the other down. Same as the normal profile with automatic setting.

 Musics : demonstrator use case that enables the playback of music note using frequency/period setting. A simple finite music list is available for selection (a buzzer must be connected to the PWM1 output for playback).

The PWM controls are shown in figures

44

to 46 .

UM2131 Rev 6

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