In which scenarios GDU Broken could occur in S12ZVM?

[chdingding]

Hi,

when I set PWM signal 100% duty, the motor's full speed is 2800rpm, and the current is about 37A,   I adjust PWM  duty

= 10%  let motor to stop, then i will  adjust PWM  duty = 100% suddenly,  Repeat a few times（run--stop---run------）as

soon as possible, after this GDU will broken. After I changed a new MCU, it will work.

what reasons can cause this problem?

[pachamatej]

Hello,

I'm not sure what HW configuration do you use, but in general, GDU of MagniV devices is sensitive to voltages higher than 40 Volts. This can be easily achieved by inducing a high voltage on HD or CP/VCP pin (thus on DC-bus "+" pole) or on the motor phase pin (the overvoltage peak goes via the bootstrap capacitor, superposes on the 11V regulator voltage).

Use a higher sampling rate oscilloscope and higher bandwidth probe to measure the overvoltage peak. If the peak is there (higher than approx. 35 Volts), then consider to implement some RC-filters to the HD/CP/VCP or VBS pins as indicated in the reference manual (Figure 18-20 - optional filters - the same filter can be applied to the HD pin).

If the filter doesn't help, the power traces on PCB should be optimized in terms of parasitic inductance.

I hope it helps,

Best regards,

Matej