DRV8210EVM: Only input 3.75V to VM of DRV8210EVM, the VCC_DRV pin can measure 3.3V

I only give 3.75V to DRV8210EVM from VM and not giving any signal to other pins including VCC_DRV. However, I measured 3.3V from VCC_DRV. My problem is why VCC_DRV would output voltage? I think VCC_DRV is for the input voltage of the external MCU 

Best regards,

Thomas.