TPS53355: Vf of Low Side FET body diode

Ryuji

Guru 20090 points

Part Number: TPS53355
Other Parts Discussed in Thread: TINA-TI,

Hello,

Could you please let me know the Vf specification of Low Side FET body diode?

Best Regards,
Ryuji

over 8 years ago

0 JohnTucker over 8 years ago

TI__Guru**** 191445 points

I believe only the on resistance is specified for the internal FETs. Is there a particular reason why you are looking for the body diode voltage?

0 Ryuji over 8 years ago in reply to JohnTucker

Guru 20090 points

Hello John san,

For calculate power dissipation of FET when FET is not turned on.
I simulate TPS53355 sw waveform by TINA-TI reference design.
As a result Vf is about 211mV. Is it correct ?
I would like to know reference value.

Best Regards,
Ryuji

0 JohnTucker over 8 years ago in reply to Ryuji

TI__Guru**** 191445 points

I suspect the TINA model only models the RDSon. I would expect the body diode Vf at about 0.6 V.

0 Ryuji over 8 years ago in reply to JohnTucker

Guru 20090 points

Hello John san,

In TINA-TI simulation, I could see the voltage drop at the dead time as 211mV.
Is this not Vf of low side FET body diode?

Ryuji

0 JohnTucker over 8 years ago in reply to Ryuji

TI__Guru**** 191445 points

Ryuji,

I would have to look specifically into the internal TINA model. 211 mV seems way too low compared to what I have seen in real life. I do not know of any Schottky type diodes with Vf that low, much less a body diode.

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TPS53355: Vf of Low Side FET body diode