TPS54202: SW absolute max ratings

Naizeng Wang

Part Number: TPS54202
Other Parts Discussed in Thread: TPS54228, , TPS54428

Hi team,

I found that the absolute max ratings of sw pin is -0.3V for tps54202 while it's -2V for tps54228. Does this mean TPS54228 has better capability of preventing negative voltage than TPS54202?

Br,

Nison

over 3 years ago

0 Young Zhao over 3 years ago

TI__Genius 9280 points

Hi Nison,

I'm not sure about this. But tps54202 is a 28V device, while tps54228 is only 18V . I think the TPS54202 MOSFET should be stronger .

For the min rating SW voltage , you can refer this APP note .

https://www.ti.com/lit/an/slva494a/slva494a.pdf?ts=1617686255752&ref_url=https%253A%252F%252Fwww.bing.com%252F

BRs,

Young

0 Naizeng Wang over 3 years ago in reply to Young Zhao

TI__Expert 3735 points

Hi Young,

As far as I know, TPS54202 and TPS54228 are both sync devices. So there are reverse diode between SW and GND. Does this spec mean that the Vf of TPS54202's body diode is much lower than TPS54228's body diode?

Nison

0 Young Zhao over 3 years ago in reply to Naizeng Wang

TI__Genius 9280 points

Hi Nison,

I'm not familiar with TPS54428, will forward this post to Tahar Allag to check the body diode of TPS54428.

BRs,

Young

0 Amod Vaze over 3 years ago in reply to Naizeng Wang

TI__Mastermind 21755 points

HI Naizeng,

It is not clear on why there is a difference in the negative SW rating between the two devices and I will try to check with design In any case, I would recommend sticking to the limits mentioned in the datasheet. Please let me know if there are any more questions.

Thanks,
Amod

0 Amod Vaze over 3 years ago in reply to Amod Vaze

TI__Mastermind 21755 points

Hi Naizeng,

Young is looking into the SW rating on the TPS54202 again to confirm if it is -2V or -0.3V.

Thanks, Amod

+1 Young Zhao over 3 years ago in reply to Naizeng Wang

TI__Genius 9280 points

Hi Nison,

I checked a lot of parts about this value description , there are different description like -0.3V/-1V/-2V for different projects. While, I believe the internal design is the same without any special consideration.

From application side, I think SW DC voltage wouldn’t go to -2V level because it will be clamped by LSD body diode. In lab test, if we force SW=-2V through a power supply, LSD may be damaged by thermal breakdown.

So above all, we can take there no big diffrence about this value , and i think -0.3v/-1v is more reasonable .

BRs,

Young

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TPS54202: SW absolute max ratings