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I want to do reverse engineering of this module (Digital Microphone)

First of all I tried to get the schematics from the supplier but they don't have them.

Finally I starting unsolder each capacitor, as I can see, all are ceramic capacitor (I guess) and measure each ones with the multimeter.

I got the following values.

74 nF I rounded it to commercial value, 0.068 uF
1,049 uF, I rounded it to commercial value, 1 uF
38,5 nF, I rounded it to commercial value, 0.039 uF
75 nF, I rounded it to commercial value, 0.068 uF
110 nF,I rounded it to commercial value, 0.1 uF

My doubts are:
1) are they ceramic capacitors? 2) is correct the procedure of unsolder and measure?
3) Is there another procedure to do it?

I read the datasheet of the principal component (microphone and amplifier) because I want to find some schematics proposal but it doesn't help me. (I am an enthusiast hobbyist)

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  • \$\begingroup\$ yes a good RLC meter and desoldering station taking care not to overheat them so that the ceramic starts to ooze liquid from the terminals \$\endgroup\$ – Sunnyskyguy EE75 Jul 19 '18 at 22:33
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1) Are they ceramic capacitors?

The capacitors in the photo of the link appear to be 0603 ceramic capcitors.

2) is correct the procedure of unsolder and measure?

Yes, usually the best way is to unsolder because the other parts of the circuit are in parallel with the capacitor. By taking it off the rest of the circuit is not measured. I do this all the time (especially when I forgot to write down what I put on my PCB)

3) Is there another procedure to do it?

An RLC meter (or tweezers) can be useful. It's most useful if you don't wish to pull the parts off the board, they can get withing 10% most of the time so if you have an idea of what the capacitance could be they are a great way to check.

It may be better to get one or more boards and repeat the measurement and average the capacitor values together because of capacitance tolerances.

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  • \$\begingroup\$ wow, thanks a lot both (Tony and Laptop2d) for your fast answer.. I have a Keysight U1282A I think it is enough to measure the capacitance... \$\endgroup\$ – RicardoV Jul 20 '18 at 2:44
  • \$\begingroup\$ meta.stackexchange.com/questions/126180/… \$\endgroup\$ – laptop2d Jul 20 '18 at 4:34

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