LM76003: Can LM76003 block reverse current

Sunny Qin

Part Number: LM76003

Hi Team,

we are promoting LM7003 in our customer, to replace LT8612, customer meet some issue on LT8612, when system power off, they found VIN of DC/DC drop much fast than Vout(24V in to LT8612, 7V out), thus reverse current flow from Vout to Vin and LT8612 broken sometime, so i am touching with you if LM76003 can block reverse current? can LM76003 survive in this condition?

Thanks very much.

Regards, Sunny

over 5 years ago

0 Neal Zhang over 5 years ago

TI__Expert 4720 points

Hi Sunny,

LM76003 will behave the same.

When Vin is lower than Vo, current will flow through the high side MOS's parasitic diode. If the current is large, it will damage the IC. Most buck converters will behave the same. Please add a diode at the output or input of the converter.

0 Sunny Qin over 5 years ago in reply to Neal Zhang

TI__Expert 4890 points

HI Neal,

Thanks for reply, is it avaliable to add the diode between the output capacitor and feedback resistor, then diode drop will cancel by feedback?

dose this circuit will affect the stability of DC/DC?

Thanks.

Regards, Sunny

0 Neal Zhang over 5 years ago in reply to Sunny Qin

TI__Expert 4720 points

Hi Sunny,

Yes it may affect the loop. Please add the diode after the output cap, or before the input cap.

0 Sunny Qin over 5 years ago in reply to Neal Zhang

TI__Expert 4890 points

Hi Neal,

Many thanks for your help~

Regards, Sunny

0 Neal Zhang over 5 years ago in reply to Sunny Qin

TI__Expert 4720 points

OK. I will close it now.

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LM76003: Can LM76003 block reverse current