TPS54620 PWRGD delay time

K. Sasaki14

Other Parts Discussed in Thread: TPS54620

Does TPS54620 have PWRGD delay time after VSENSE pin voltage becomes power good range?

According to datasheet, PWRGD is pulled low when SS/TR pin is below 1.4V. Thus I think TPS54620's PWRGD has 0.75*SS time delay.

Is my idea correct?

Best Regards,

Kohei Sasaki

over 10 years ago

0 JohnTucker over 10 years ago

TI__Guru**** 191445 points

It is not a delay time. PWRGD is just inhibited if SS/TR is below 1.4 V. There is otherwise no appreciable delay.

0 K. Sasaki14 over 10 years ago in reply to JohnTucker

Guru 10200 points

John-san,

Thank you for your reply.

I understood it is not delay.

How long is the period until PWRGD becomes Hi-Z from output voltage rise up to setting value? I think it is 0.75*SS time. Is this correct?

Best Regards,

Kohei Sasaki

0 JohnTucker over 10 years ago in reply to K. Sasaki14

TI__Guru**** 191445 points

Assuming that the SS/TR voltage continues to rise at a linear rate, then it is .75 x SS time. If SS/TR never reaches 1.4 V (like in some invalid tracking sequence), the PWRGD will never come on.

0 K. Sasaki14 over 10 years ago in reply to JohnTucker

Guru 10200 points

John-san,

Is this 1.4V of SS/TR correct value? According my observation with EVM, I think it is about 1.2V.

Best Regards,
Kohei Sasaki

0 JohnTucker over 10 years ago in reply to K. Sasaki14

TI__Guru**** 191445 points

The 1.4V is typical value. I doubt that there is any statistical data for that parameter. In any case, the SS/TR pin should always pull up above that value in normal operation.

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TPS54620 PWRGD delay time