DRV8353R: heat

Hi Annie,

Can you provide the schematic? Are VDRAIN and VM connected? Please see this app note: LINK

Thanks,

Matt

Hi Matt,

VDRAIN and VM are connected together. 

Is the VM voltage too high, and the internal linear voltage regulator dissipation power is too high? Need to use DCDC to generate 12 to 15v to connect to the VM.

Thanks,

Annie

Hi Matt,

The customer adjusted the internal DCDC output voltage of the DRV8353 to 12v, and then connected it to the VM. He found that 12v was normal at the beginning, but after a while, the voltage output of DCDC was not 12v, but was always lower than the VIN voltage by 4V as VIN changed. For example, if VIN is 31v, then the DCDC output is 27v; VIN is 29v, and the DCDC output is 25v. However, DRV8353 can still be used normally after DCDC output is connected to the 3.3v produced by LDO to power the system. May I know is this DRV8353 damaged?

Thanks,

Annie

Hello Annie,

It sounds like either the DRV8353 is damaged or there is an external path from VDRAIN to VM causing VM voltage to rise. You may want to disable the DC/DC and check on the board where the voltage is coming from.

Thanks,

Matt

Hi Annie,

Is any additional assistance needed on this case?

Thanks,

Matt

Hi  Matt,

The customer did not give me any response. You are able to close this thread now. Once there is feedback, I will let you know.

Thanks,

Annie

Thanks Annie!