TPS92692-Q1: ESR of the output capacitor adds ripple,

cao sh

Part Number: TPS92692-Q1

Tool/software:

Why does the calculation of ESR ripple in Formula 13 include the Iout(max)/(1-D) term? This seems to be the DC component

2 months ago

0 Daniel Louis 2 months ago

TI__Expert 5790 points

Hi Cao,

Please refer to the following app note and post:

e2e.ti.com/.../lm5122-output-voltage-ripple-calculations

https://www.ti.com/lit/an/slvaf30/slvaf30.pdf?ts=1751389914693&ref_url=https%253A%252F%252Fe2e.ti.com%252F

Best,
Daniel

0 cao sh 2 months ago in reply to Daniel Louis

Prodigy 50 points

Dear Daniel,

Tks, I still don't grasp how it works. Iout(max)/(1-D) +ΔL/2 should be the current flowing through the output power transistor and will not all flow through the ESR.

0 Daniel Louis 2 months ago in reply to cao sh

TI__Expert 5790 points

Hi Cao,

The output cap is a bulk cap which sources voltage and current when the FET switches on/ off depending on the topology. During these transient events, the ESR will add ripple.

Best,
Daniel

Power management

Power management forum

TPS92692-Q1: ESR of the output capacitor adds ripple,