In a recent design we've encountered an issue with DRV8353SMRTAT in 3x PWM mode.
Namely, it seems that the IC is not behaving as 3X PWM configuration although the configuration register
indicate that properly (register 0x02 "Driver Control" value is 0x0020).
Schematic and capture of SPI transaction of reading register 0x02 below:
The issue manifests itself by a slow ramp from GND level to ~10V, as indicated in the image below
(yellow trace GHx, blue trace GLx, measured with respect to GND):
The hardware is configured for only 3x PWM configuration, by pulling the INLx signals to logic level supply (3.3V).
When modifying the hardware such that the INLx signals are pulled to ground, then correct behaviour of GHx signals is
observed (although GLx signals not switching as it seems that the gate driver is in 6x / independent PWM mode)
(yellow trace GHx, blue trace GLx, measured with respect to GND):
What could the possible cause be for such behavior and are there any suggestions on what to test further?
