LMR36506-Q1: output back feed

Max Chen1

Intellectual 715 points

Part Number: LMR36506-Q1

Tool/software:

Hi,

I use LMR36506-Q1 as Vbus (5V) generation for USB2.0 OTG application

VIN =12V

Vout=5V

;;;; Vout connect to USB connector Vbus

when we plug the USB to the computer which is host, we noticed that VIN = Vout when VIN has not applied.

Question: will this back power damage the LMR36506-Q1?

Thanks

6 months ago

0 Richard Fu22 6 months ago

TI__Mastermind 31255 points

Hi Max,

Typically we do not recommend this application. If you need to prevent backfeeding, add a diode at the input of the VIN pin. This will force the current to divert through the feedback resistor divider.

Thanks,

Richard

0 Max Chen1 6 months ago in reply to Richard Fu22

Intellectual 715 points

Hi Rich,

what do you recommend for this application?

any recommended parrt?

Thanks

Max

0 Richard Fu22 6 months ago in reply to Max Chen1

TI__Mastermind 31255 points

Hi Max,

No particular recommendation, a Schottky diode would be the best one to start, in order to minimize the diode forward voltage loss. As long as diode reverse voltage is rated for maximum VIN and can support the input current at full load.

Thanks,

Richard

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LMR36506-Q1: output back feed