56.6.5.2.1 Application Example
The external PWM Start mode generates a modulated frequency PWM signal with a constant active level duration (tON) and a minimum inactive level duration (minimum tOFF).
The tON time is defined by the CDTY value in the PWM Channel Duty Cycle Register. The minimum tOFF time is defined by CDTY - CPRD (PWM Channel Period Register). This mode can be useful in Buck DC/DC Converter applications.
When the output voltage VOUT is above a specific threshold (Vref), the PWM inactive level is maintained as long as VOUT remains above this threshold. If VOUT is below this specific threshold, this mode ensures a minimum tOFF time required for MOSFET driving (see the figure below).
