Hi,
I was using TMDSHVMTRPFCKIT for BLDC_sensorless project. The original settings of f2803xbldcpwm.h file is High side PWM switching and Low side ON (H_PWM_L_ON mode). However, my research involves PWM switching at the Low side of the transistors and I was doing fine with the codes in TMDSHVMTRPFCKIT.
The problem is I've changed to DRV-8312 69m kit now and I have some difficulties understanding the codes and schematic of the switching inside the DRV-8312.
First, I copy some of the codes from the f2806xbldcpwm.h file from the project of DRV-8312 69m kit, shown below. Where is the EPWM 1B connecting to the Figure attached? Is it PWM_AL or RESET_A?
EPwm1Regs.AQCSFRC.bit.CSFB = 0;
EPwm1Regs.AQCTLB.bit.CAU = 2;
EPwm1Regs.AQCTLB.bit.ZRO = 1;
EPwm1Regs.CMPA.half.CMPA = (int16)(Tmp>>15);
EPwm1Regs.AQCSFRC.bit.CSFA = 2;
EPwm2Regs.AQCSFRC.bit.CSFA = 1;
EPwm2Regs.AQCSFRC.bit.CSFB = 2;
EPwm3Regs.AQCSFRC.bit.CSFA = 1;
EPwm3Regs.AQCSFRC.bit.CSFB = 1;
Second, where is the RESET_A connecting to the MOSFET in the Inverter? From my understanding, the 6 MOSFETs in the inverter of the attached figure are controlled only by three singnals, the PWM_AH, PWM_BH and PWM_CH. In this case, how can the BLDC motor conduct only two phases per state?
My questions are a little bit complicated. To sum up, I just want to know what is the difference of the PWM switching between these two kits. My goal is to apply PWM switches on both High side and Low side of the transistors. Any help would be greatly appreciated.
Best regards, Samuel