TPS54202: output ceramic capacitor replacement with hybrid capacitor

Pawan Shiv V

Prodigy 20 points

Part Number: TPS54202

Hi,

We are designing 2 buck regulators for our project, specifications for which are as below:

1) I/P V: 15V to 26V, O/P V: 12V, O/P I: 1.2A

2) I/P V: 15V to 26V, O/P V: 5V, O/P I: 1.0A.

Currently we are using 33uH inductor and 2*22uF/25V,1210,X7R capacitors.

We wanted to replace these ceramic capacitors with polymer caps eg: EEHZC1V470P or HHXA350ARA470MF61G

a. Can we replace ceramic capacitors directly with polymer caps?

b. Effect on stability of feedback loop?

c. Addition of 1uF/10uF ceramic capacitor in parallel to polymer capacitor. Will it help?

over 7 years ago

0 Shawn Nie over 7 years ago

TI__Genius 10070 points

Hi,

Yes, you can replace ceramic capacitors with polymer capacitors, there is no influence on stability.
As you know, ESR of polymer caps is larger than ceramic caps, the output voltage ripple is larger, so it will be helpful if you add ceramic caps in parallel to polymer.

Shawn

0 Pawan Shiv V over 7 years ago in reply to Shawn Nie

Prodigy 20 points

Thanks Shawn.
I was only concerned because TPS54202 is internally compensated. We just have got feed forward capacitor which we can play with if some compensation is required.

Pawan

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TPS54202: output ceramic capacitor replacement with hybrid capacitor