DRV8303: MOSFET of DRV8303 have a large heat dissipation in no load condition

Part Number:DRV8303

Hi,

I didn't connect the motor, so it is in no load condition. The input is 24V. I found the MOSFETs were very hot and there was 0.5A current on 24V power supply. I though it might be switching loss so I measured the current (voltage of current shunt, CH1) and the low side Vds(CH2). I found the suspected switching loss as below figure shows. I tried to change the DTC from 1ohm to 100kohm. However, the switching loss remain the same. At last, I found the CH1 was actually switching noise, it was not the real current waveform. At first, the drive current was set as 0.7A. I reduced the gate resister from 10ohm to 4.7ohm and found the current consumption was reduced by 100mA. I was going on to set the drive current to 1.7A, but the current consumption remained as 0.5A-0.1A=0.4A.

Could you suggest what else I could try to find and solve the loss issue? Thank. Below is the link for the MOSFET,

I also attached the schematics of DRV8303.