LM5143: Need gate source resistor for LM5143?

Andrew Massey

Part Number: LM5143

Hi,

LM5143 datasheet seems to say that if no gate-source resistor, and that channel gets disabled (EN=0), then its hi side FET will end up getting turned ON and staying ON?

over 1 year ago

0 Timothy Hegarty over 1 year ago

TI__Guru 74162 points

Andrew,

There is a weak gate pulldown when EN (and thus VCC) are low. We haven't seen any issues, but you can add a 100kΩ resistor from gate to source.

Regards,

Tim

0 Andrew Massey over 1 year ago in reply to Timothy Hegarty

Prodigy 90 points

Thanks, also when doing a dual buck single output...is it possible to actually disable just one of the channels?...eg in light load?

+1 Timothy Hegarty over 1 year ago in reply to Andrew Massey

TI__Guru 74162 points

Yes, you can pull EN2 low to disable the 2nd phase.

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LM5143: Need gate source resistor for LM5143?