CCS/DRV8301: No pwm output when nFAULT and nOCTW are high

Part Number:DRV8301

Tool/software: Code Composer Studio

Hi all,

Now, I use DRV8301 as gate drivers, however,  when I input the low side pwm signal at pin 22 (INL_C), then I measure the output signal of pin 35 (GL_C), I get nothing.

I only supply PVDD1=18V, PVDD2=0, GVDD=11V, AVDD=6.6V and DVDD=3.348V. The pull high and EN_GATE voltage of nOCTW & nFAULT are 5V. Thermal PAD connects to GND using a DuPont line.

But the nOCTW & nFAULT are 5 and 4.2V. It means there is no fault and warning.

The picture of signal is shown below. (Red is nFAULT, Yellow is nOCTW, Blue is input pwm and Green is output pwm.)

I don't know why the output pwm is when there is no error and warning.

Thanks in advance,

Bojun Wang.