LP38798 - About usage when this device is disabled

Went to the bench with an LP38798EVM to test this.

Under the conditions described (EN pin low, output forced to 2V) the LP38798 output will be sinking about 350mA.

The LP38798 appears to re-start into this pre-biased output condition without problem.

Hi Donald-san,

 

Thank you for your kind support!

I have one more question.

Does this sink current (about 250mA) flow to GND?

So, I understand that this sink current doesn’t flow to VIN.

Is my understanding correct?

 

Regards,

Kanemaru

Based on the EVM behavior, yes current flows to ground. The exact path is unknown. I suspect parasitic PN junction breakdown somewhere in the output stage, but I have no evidence to support this.

I have no data to support the current flow path shown in your drawing.

Hi Donald-san,

 

I greatly appreciate your cooperation!

I understand that LP38798 is not failed by this sink current.

Is my understanding correct?

 

Regards,

Kanemaru

This is not an ensured operating condition, customer does this at their own risk.

In my very small sample testing I did not see any device failures.