# Buck Converter 72V(I/p) - 16V(o/p) 1A Need Help on Capacitor Values

#### AjaxKrish

Joined Dec 5, 2021
2
MP9486 I'm trying to design a 72v input to 16v output with 1A and 20% ripple current with MP9486. I'm stuck with calculating the Capacitor Values.

#### Papabravo

Joined Feb 24, 2006
18,103
Since you have decided to provide minimal information and no schematics, I can't help you. I can point you to a potential reference that may be of some assistance. It's a tough read, but I'm sure you can handle it.

https://www.ti.com/lit/an/slva477b/slva477b.pdf

#### Ian0

Joined Aug 7, 2020
4,865
MP9486 I'm trying to design a 72v input to 16v output with 1A and 20% ripple current with MP9486. I'm stuck with calculating the Capacitor Values.
Ripple current is of far more importance than the capacitance value.
Find a capacitor with enough voltage rating and enough ripple current rating, and it will most likely have enough capacitance.

#### ronsimpson

Joined Oct 7, 2019
2,007
Page two is a good place to start. Pick a different R1 to get 16V. Change C2a and b to 25V parts.

#### Papabravo

Joined Feb 24, 2006
18,103
Page two is a good place to start. Pick a different R1 to get 16V. Change C2a and b to 25V parts.
View attachment 254245
Great advice. When in doubt RTF[Datasheet, Manual, AppNote,...]
Don't fall into the trap of thinking you are done. Trust, but verify. Truer words were never spoken.

#### AjaxKrish

Joined Dec 5, 2021
2
Page two is a good place to start. Pick a different R1 to get 16V. Change C2a and b to 25V parts.
View attachment 254245
Thanks, It took me a while to understand what u said, so accordingly I got R1 to be as 790K(680K+100k+10K) AND R2- 10K and c2a and c2b for 25V. Can I go with that? Is there any other way than this? Can I Simulate this in MATLAB?

Sorry for late Response and Happy NEW YEAR

#### Ian0

Joined Aug 7, 2020
4,865
c2a and c2b for 25V. Can I go with that?
No use just specifying the capacitance. Ripple Current is MUCH more important.