TPS63020 PS/SYNC pin PWM pulse frequency limitation

Paul Yeh

Other Parts Discussed in Thread: TPS63020

Hi expert,

My customer would like to know the PWM frequency limitation in PS/SYNC pin that won't let IC misjudge to enter snychronous state.

My customer's application condition is in below

==>In Battery mode, they will let TPS63020 operate in power saving mode

==>In Adaptor mode, they will let TPS63020 operate in PWM mode

But they will do adaptor plug in and plug out test repeatedly, so the PS/SYNC pin signal will sometimes High and sometimes Low. We can’t predict their plug in/out frequently.

That’s why customer would like to know our limitation at PS/SYNC pin. They don’t want this signal to cause device enter SYNC condition because of this waveform. I also draw simple diagram to express PS/SYNC pin waveforms for your reference.

Please advice ASAP.

Thanks

over 14 years ago

0 Daniel Acevedo over 14 years ago

TI__Genius 17240 points

For the TPS63020 to SYNC, the frequency would have to be in the MHz range. Even if this happens due to a bounce, the converter will return to the free-running frequency if a SYNC signal is not received within several switch cycles.

0 Paul Yeh over 14 years ago in reply to Daniel Acevedo

TI__Genius 16185 points

Hi Daniel,

So base on your comment, customer doesn't worry about adaptor plug in/out repeatly to induce this PWM signal in PS/SYNC pin, right?

Due to no one can plug in/out so fast up to MHz speed.

As for bounce problem, I think I can ask customer to add small cap, maybe pF in PS/SYNC pin to filter, am I right?

Thank you and regards

0 Daniel Acevedo over 14 years ago in reply to Paul Yeh

TI__Genius 17240 points

Correct; the bounce shouldn't be a problem either.

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TPS63020 PS/SYNC pin PWM pulse frequency limitation