TPS53219A: Open TRIP pin and Mode pin

user4979989

Part Number: TPS53219A

Hi team,

My customer would like to know what will happen once TRIP and MODE pins are floating.

We all know these are not normal conditions, but there is an issue in customer factory side so customer wants to know the concerns.

1. What will happen if TRIP and MODE pins floating before powering up

2. What will happen if TRIP and MODE pins floating during normal operation

Thanks.

Regards,

Allen

over 5 years ago

0 JohnTucker over 5 years ago

TI__Guru**** 191445 points

Allen,

I am pretty sure I know the answer, but I need to double check before posting. I'll get back to you soon.

0 JohnTucker over 5 years ago in reply to JohnTucker

TI__Guru**** 191445 points

Allen,

An open MODE pin will certainly give you the longest soft-start time setting because this is determined at IC start-up by driving a voltage and reading the current. No resistor/current means you’ll get 5.6ms soft-start. However, after that, the MODE pin is continuously monitored for Auto-skip. With it floating, I can’t ensure whether it will be in Auto-skip or FCCM.

An open TRIP resistor will give you a very large OC limit. No harm unless you need protection.

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TPS53219A: Open TRIP pin and Mode pin