LMR38020-Q1: Bypass Capacitor

CHIN NAN

Part Number: LMR38020-Q1

Hi Sir,

Could you please give guidance for how to calculate the input bypass capacitor for power supply to meet the ISO 16750-2 4.4 ( Superimposed alternating voltage).

Regards,

CHINNAN C V

over 1 year ago

0 Elena Gao over 1 year ago

TI__Genius 13735 points

hi, Chinnan,

A few 10nF caps and some 10uF/50V caps is typically a good starting point. Usually based on DS application circuit is good to use.

What's detail in ISO 16750-2 4.4 ?I am not very familiar with its requirements.

Elena

0 CHIN NAN over 1 year ago in reply to Elena Gao

Prodigy 160 points

The 16750-2 4.4 is basically checking how to eliminate the AC content in the power supply line.

The peak to peak will be 1V

The freq Varies from 50 Hz to 25 KHz.

The waveform given below.

Pls guide how to bypass this ac element using cap

0 Elena Gao over 1 year ago in reply to CHIN NAN

TI__Genius 13735 points

I will reply to you next Monday.

0 Elena Gao over 1 year ago in reply to Elena Gao

TI__Genius 13735 points

hi， Chin，

Looking from EVM suggestion ,please see the input side have 33 bulk and 2.2uf+100nf +1nf MLCC

https://www.ti.com/lit/ug/snvu817/snvu817.pdf?ts=1699849573491&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FLMR38020-Q1

and if you can also design a RC with 25k=1/2pi*RC

Elena

0 Elena Gao over 1 year ago in reply to Elena Gao

TI__Genius 13735 points

Close this ticket first for no updates, and if you have question please reopen here.

Elena

Power management

Power management forum

LMR38020-Q1: Bypass Capacitor