TPS54628 Output Voltage 0.9V with /-1% accuracy

Xingwen Wei

Prodigy 130 points

Other Parts Discussed in Thread: TPS54628, TPS54478, TPS54318

Hi Sir,

We use TPS54628 like this:

1> Input 5V; Output 0.9V

2> Current: 3A

3> Output ripple: 5mVpp

4> Resistor Divider: +/-0.1% accuracy

5> Operation Temp: -40 ~85C

Question:

a, Can we control TPS54628 output ripple less than 5mVpp? If not, any other suggestion?

b, Is it possible to make the 0.9V output accuracy within +/-1%?

Thanks,

Xingwen

over 8 years ago

0 JohnTucker over 8 years ago

TI__Guru**** 191445 points

TPS54628 is +/- 1.8% Vref accuracy. 5 mV ripple is difficult to achieve without additional filtering or using an LDO follower. If you use an LDO follower the output voltage accuracy will be dependent on the LDO.

0 Xingwen Wei over 8 years ago in reply to JohnTucker

Prodigy 130 points

Hi John,

Thanks for your reply!

By your experience, is it possible to control the ripple within 5mVpp or 2mVpp?

Do you have any higher accuracy DC regulator to recommend to acheive +/-1% output accuracy?

Thanks again,

Xingwen

0 Xingwen Wei over 8 years ago in reply to Xingwen Wei

Prodigy 130 points

Hi John,

Could you please give us some suggestion?

Thanks,

Xingwen

0 JohnTucker over 8 years ago in reply to Xingwen Wei

TI__Guru**** 191445 points

I would probably start with TPS54318 or TPS54478.

0 Xingwen Wei over 8 years ago in reply to JohnTucker

Prodigy 130 points

Thanks John.

I checked the datasheet of these two parts. The refernce voltage accuracy is +/-1%. So plus the output ripple, the output voltage accuracy will bigger than +/-1%.

What is the highest reverence volatge accuracy do you have?
By your experience, is it possible to control the ripple within 5mVpp or 2mVpp for switch regulator?

Thanks,
Xingwen

0 Xingwen Wei over 8 years ago in reply to Xingwen Wei

Prodigy 130 points

Hi John,

Is thare any way I can send you email directly? That will be more effecient.

Thanks,

Xingwen

0 JohnTucker over 8 years ago in reply to Xingwen Wei

TI__Guru**** 191445 points

j(dash)tucker(at)ti(dot)com

0 JohnTucker over 8 years ago in reply to JohnTucker

TI__Guru**** 191445 points

although I answer forum posts just as fast as emails...

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TPS54628 Output Voltage 0.9V with /-1% accuracy