topic Re: Getting the EMI Peaks : MMPF0100F0AZES in Power Management

Getting the EMI Peaks : MMPF0100F0AZES

pratikpanchal — Tue, 14 Dec 2021 15:47:51 GMT

Hello Team,

We are getting the EMI peaks between 30MHz to 600MHz from the PMIC. The major peak is 357MHz.

Here is the schematic design (PMIC.pdf) for your reference.

Also, I have attached the snapshot(tek00031.png) for EMI peaks for your reference.

Kindly let us know the work around for the same ASAP as we are blocked in the final FCC certification.

guoweisun — Wed, 15 Dec 2021 05:11:09 GMT

The PMIC switch frequency is up to 1-2MHz,but in your EMI issue test up to 600MHz,how do you know this issue caused by PMIC?

You should add common mode choke to solve this issue in system circuit.

pratikpanchal — Wed, 15 Dec 2021 05:17:57 GMT

I have near field probe in-house. So whenever I hover the probe over the PMIC then only I am getting this noise.

I checked full board this much of noise only generated by PMIC only.

Where exactly you are suggesting adding a common mode choke in the design?

guoweisun — Wed, 15 Dec 2021 05:21:41 GMT

In the PMIC input rail add common mode choke,for the detail value you should try by test.

pratikpanchal — Tue, 04 Jan 2022 14:48:27 GMT

Hello Team,

I Captured the switching waveform of all the switcher.

Kindly have a look and let me know its desired results or not.

guoweisun — Tue, 11 Jan 2022 01:30:45 GMT

Add common choke at the VIN terminate of PMIC to try.

pratikpanchal — Wed, 02 Feb 2022 07:24:31 GMT

I have few queries

1) What is difference between MMPF0100 & MMPF0100Z chipset.?

2) What is default switching frequency of MMPF0100 & MMPF0100Z ?

3) Which value do we needs to configure for changing the switching frequency?

guoweisun — Mon, 07 Feb 2022 00:21:01 GMT

1.PF0100Z version differences in the PF0100Z datasheet page4

2: 1MHz is default switching frequency of MMPF0100 & MMPF0100Z .

3;Which value do we needs to configure for changing the switching frequency?

[GW]SWxFREQ[1:0]