Using TMS320F28035 to generate half bridge switching pattern

I can generate a proper half bridge gate signal with this code.  But not sure if this is the most effective way.  This method need to setup both CMPA and CMPB.  Anyway, don't know why TI make such a mistake in their document.

   EPwm1Regs.AQCTLA.bit.ZRO = AQ_SET; // set actions for EPWM1A
   EPwm1Regs.AQCTLA.bit.CAU = AQ_CLEAR;
   EPwm1Regs.AQCTLB.bit.PRD = AQ_SET; // set actions for EPWM1B
   EPwm1Regs.AQCTLB.bit.CBD = AQ_CLEAR;
   EPwm1Regs.CMPA.half.CMPA = 100; // adjust duty for output EPWM1A & EPWM1B
   EPwm1Regs.CMPB = EPwm1Regs.TBPRD - EPwm1Regs.CMPA.half.CMPA;

I will submit a request to have the diagram changed.

Regarding the waveform generation, you can consider these settings:

EPwm1Regs.AQCTLA.bit.ZRO = AQ_SET; // set actions for EPWM1A
EPwm1Regs.AQCTLA.bit.PRD = AQ_CLEAR;
EPwm1Regs.AQCTLB.bit.PRD = AQ_SET; // set actions for EPWM1B
EPwm1Regs.AQCTLB.bit.ZRO = AQ_CLEAR;

This will generate full 50% duty waveforms for HB switching.  You can then use the dead-band module to add dead time between the PWM waveforms.

Daniel,

Thanks!  However, 50% duty waveforms is normally used in phase-shift full bridge, the reason is that we can shift the phase to control the power to deliver to the load.  But for half bridge, duty is commonly used to control the power.  If duty is fixed at 50%, the only way to change output power is to change the rail voltage.  To follow textbook, half bridge requires change of duty.  What do you think?

Kelvin

Any idea of how to trigger the ADC in the middle of the pulse?