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I want to use the DRV8300 to drive three half-bridges. However the schematics inside the datasheet does not seems to work. When I try to scope VDS, it seems VDS seems to be too small on the upper FET.

Phao
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    you need to be running a pwm signal in order for the high side boost circuit to operate. 220pF seems a bit low for the boost capcitors - did you follow the calculations in the datasheet? How about the voltage rating of the diodes? – Kartman Jun 15 '22 at 11:14
  • Do you mean INH? Those are connected to the INH output of the microcontroller – Phao Jun 15 '22 at 11:16
  • the microcontroller must be generating a pwm signal. – Kartman Jun 15 '22 at 11:20
  • Yes, the microcontroller is generating the signal – Phao Jun 15 '22 at 11:20
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    Your bootstrap capacitors are ridiculously small. The example in the datasheet calculates a value almost 500x larger than what you have there. Similarly for your Cgvdd cap - that's comically tiny compared to the datasheet's recommended 1uF value. – brhans Jun 15 '22 at 11:42

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Look at section 9.2.1 in the datasheet for information on how to calculate the minimum value of the bootstrap and GVDD capacitors. 220pF for the bootstrap caps is way too low, 100 nF-1 uF is probably the range you need but it depends on your PWM frequency which you don't state. 100 pF is also too low for the GVDD cap.

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John D
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