Deep Dive into ESR, Introduction

RE: Deep Dive into ESR, Introduction

fmilburn — Sat, 11 May 2019 01:26:36 GMT

Taking into account Michael's comments about the need for higher frequency and higher current I was thinking about the following modifications to the test circuit:

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Channel 2 should see about 5 millivolts if ESR is 0.01 ohms? Separately could measure static drain to source on-resistance if that is of use.

RE: Deep Dive into ESR, Introduction

jw0752 — Thu, 09 May 2019 03:45:29 GMT

Hi Frank,

This will be a good learning experience, to follow your well laid out experiments. I also love to watch the way everyone collaborates and adds ideas. Thanks for letting me look over your shoulders and pickup some ideas and knowledge.

John

RE: Deep Dive into ESR, Introduction

michaelkellett — Wed, 08 May 2019 08:51:59 GMT

One of the caps in your kit is 220uF with a claimed ESR of 0.009 ohms (I didn't check them all).

At 100 kHz the impedance of an ideal 220uF cap is 0.007 ohms, which is significant.

Since one of the benefits of polymer caps is ultra low ESR, allowing them to replace ceramics which are also very good, you will need a very different measuring technique to measure them.

Sadly the Peak ESR70 is not up to it.

There is a good thread here:

https://www.eevblog.com/forum/projects/measuring-ultra-low-esr-caps/

The DE-5000 looks interesting.