LM34936: should we need to add MOSFET to block 5V stamdby reverse to output?

Ann_Lien

Part Number: LM34936

Hello expert,

Customer want to use LM34936 for their PD application. They want to know should we add MOSFET to block reverse current from 5V_STB to LM34936 output. Other the other words, could LM34936 could turn on successfully when output have 5V? Thanks a lot!

Best regards,

Ann Lien

over 6 years ago

0 Garrett Roecker over 6 years ago

TI__Mastermind 21720 points

Hi Ann,

Thanks for reaching out with your question. Since the 5V rail is used to pre-bias the output voltage I think would be good to have the diode to stop reverse current.

What is the target output voltage of the LM34936?

Thanks

Garrett

0 Ann_Lien over 6 years ago in reply to Garrett Roecker

TI__Genius 14430 points

Hello Garrett,

It is 5V/9V/15V/20V and they would like to know the path for reverse current. Could you kindly help to explain or draw the reverse current loop? Thanks a lot!

Best regards,

Ann Lien

0 Garrett Roecker over 6 years ago in reply to Ann_Lien

TI__Mastermind 21720 points

Ann,

I'm just referring to the reverse current that would flow in to the 5V_STB supply when the output of the LM34936 has an output voltage setting greater the 5V if the diode were not in the schematic. This is why the diode is recommended.

Thanks,

Garrett

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LM34936: should we need to add MOSFET to block 5V stamdby reverse to output?