Revisions Affected

0, A, B, C

Details

The Ramp Generator is designed to produce a falling-ramp DAC reference that is synchronized with a PWMSYNC signal. Upon receiving a PMWSYNC signal, the Ramp Generator will start to decrement its DAC value. When COMPSTS[COMPHSTS] is asserted by a trip event, the Ramp Generator will stop decrementing its DAC value.

If COMPSTS[COMPHSTS] is asserted simultaneously with a PWMSYNC signal, the desired behavior is for the PWMSYNC signal to take priority such that the Ramp Generator starts to decrement in the new EPWM cycle. Instead of the desired behavior, the COMPSTS[COMPHSTS] trip condition will take priority over PWMSYNC such that the Ramp Generator stops decrementing for a full EPWM cycle until the next PWMSYNC signal is detected.

Workarounds

Avoid COMPSTS[COMPHSTS] trip conditions when PWMSYNC is generated. For example, peak current mode control applications can limit the PWM duty cycle to a maximum value that will avoid simultaneous COMPSTS[COMPHSTS] and PWMSYNC assertions.