DRV3245Q-Q1:

We are now using the DRV3245 to drive a BLDC motor.But we got some problem on the VGHS voltage.

When the IC is enabled, the voltage on VCPH is 10V over PVDD as the DATASHEET described, but when the gate drive start to work, the VGHS voltage falls to nearly 7.5V. 

As the picture below,  PVDD voltage is measured in CH3(purple), VCPH voltage is measure in CH2(blue one),high side gate voltage GH3 is measured in CH4(green one).When the GH3 start to output PWM signal, a voltage drop happened on VCPH pin.

VGHS voltage is below 8V which makes the system easy to fail for the VGHS under voltage. And it is useless to raise the power supply .When PVDD is 14V ,VCPH is nearly 22V which shoule be 24V. When the PVDD is 16V,VCPH is only 24V.

the schematic is shown as below,the Qg(tot) is no more then 137nC.

Can you help to take a look about this problem?