DRV8432 EVM 11V output

Andy,

Looks like you are applying continously high or low logic at PWMx inputs, instead of applying PWM as continous frequency signal. This will create under-voltage lock-out for high side bootstrap power supply.

DRV8432 high-side gate driver are based on bootstrap logic, which mandates PWM signal at of 10Khz, based on 0.1uF cap provided in EVM. Pleae refer to data-sheet for more details on this.

Best Regards

Milan-Motor Application Team

I tried with a simple PWM:

  digitalWrite(PWMA, HIGH);
  delayMicroseconds(50); 
  digitalWrite(PWMA, LOW);
  delayMicroseconds(50);

Same not good result, now I have arround 13V, depends on the duty cycle.

I'm just starting with TI programming. If you can suggest me a code to try with it will be great to test with a good code. We could see if is something wrong with the EVM.

Thank you,
Andy

Andy,

What is status of other PWM pins, PWMB, C and D, while applying PWM pulses at PWMA? If they are left open or applied with high logic, device may hit under-voltage protection. To avoid this scenario, make sure that PWMB,C and D are tied to GND, and apply pulses to PWMA.

With above condition, Please share the simultaneous scope capture of voltages at PWMA and OUTA pins. This will help in understand the device behavior in more detail.

Have you decided any particular MCU from TI for this application? If not, I would suggest going with C2000 Piccolo series MCU. To start with, you can go for TMS320F28035 series. You can find the PWM code for this MCU readily available in Control-suite at: http://www.ti.com/tool/controlsuite.

Best Regards

Milan-Motor Application Team

Milan,

I add the PWM pins B,C and D to GND. the voltage is:

- 50 %  - 12V

- 60 % - 12.2V

- 90 % - 12.7V

Unfortunately I don't have now the scope here.

I'm using MSP430G2553 Launchpad. I don't have the Piccolo.
Strange is that is giving me the Gates voltage range (around 12V). At 50 % dutycycle the dutycycle recommended in the datasheet the voltage is fix 12.00V.

The capacitors at the end are not on the board C25,C26, C27, C28, C29, C30, C31, C32 are not on the EVM. Any idea why?

Thank you,

Andy

Andy,

Without Scope waveforms, it won't be possible to troubleshoot the issue. I strongly recommend that you should get the scope and send the actual waveforms. The reason is that signals are high frequency PWM waveforms, reading these values through multi-meter can be misleading.

Yes that fine, all those capacitors are not mounted on EVMs. It is stuff option to filter PWM waveforms, in case user wants to get the average DC values as output, instead of actual PWM signals at OUTx pins.

Best Regards

Milan-Motor Application Team