EEVblog Electronics Community Forum

Products => Test Equipment => Topic started by: rstofer on July 10, 2018, 09:12:23 pm

Title: Impedance Analyzer Gadget For Analog Discovery 2
Post by: rstofer on July 10, 2018, 09:12:23 pm
https://store.digilentinc.com/impedance-analyzer-for-analog-discovery/

I just ordered this to see what it can do.  Basically, it is an impedance analyzer with a bandwidth from 1 Hz to 15 MHz.

Here's the blog discussion:

https://blog.digilentinc.com/add-impedance-analysis-to-the-analog-discovery/
Title: Re: Impedance Analyzer Gadget For Analog Discovery 2
Post by: tsman on July 10, 2018, 09:19:15 pm
I saw the blog post about this board the other day and found a short review (https://gasstationwithoutpumps.wordpress.com/2018/07/01/analog-discovery-impedance-analyzer/) of it.
Title: Re: Impedance Analyzer Gadget For Analog Discovery 2
Post by: precaud on July 11, 2018, 02:36:45 am
Reasonably priced, bit it's spec'ed for a pretty limited range of impedances. In fact, they only spec it in terms of C and L:

50pF - 500µF Capacitance Measurement Range
10µH - 1000mH Inductance Measurement Range

And it's not a very wide range, at that.

No mention of minimum and maximum impedances. Or accuracy.

The topology they use, and refer to as "load first", is more commonly known as "Series-Thru". It was discussed in the teardown of the Omicron B-WIC fixture:
https://www.eevblog.com/forum/testgear/mini-teardown-omicron-b-wic-impedance-test-adapter/ (https://www.eevblog.com/forum/testgear/mini-teardown-omicron-b-wic-impedance-test-adapter/)

The general gist is, it is more useful for higher-impedance devices; smaller capacitors, larger inductors.

I think the Discovery 2 is capable of better than what this offers...

Title: Re: Impedance Analyzer Gadget For Analog Discovery 2
Post by: rhb on July 11, 2018, 11:58:35 pm
I'd like to suggest taking a close look at the input voltage ranges.  They are not likely to be robust.