I am using this MEMS microphone for a stethoscope project. The data sheet recommends the following interface circuit.

I can't seem to find where it states specifically that it is a differential output instead of a single-ended one. Am I right in understanding it as outputting a differential output?

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  • \$\begingroup\$ The mic (the piece of hardware) is only the circle with mic. Rest is hardware outside the component. Like the recommended one. \$\endgroup\$
    – RemyHx
    Dec 12, 2022 at 7:28
  • \$\begingroup\$ Do you intend to use an analog one? Or a digital? \$\endgroup\$
    – RemyHx
    Dec 12, 2022 at 7:28
  • \$\begingroup\$ Is there both, I am under the impression that the mic only output analog. I plan to feed it into a analog filter. \$\endgroup\$ Dec 12, 2022 at 8:49
  • 1
    \$\begingroup\$ Feeding straight into a differential opamp from capacitors is asking for trouble. There needs to be biasing and feedback. So, the diagram is illustrative only \$\endgroup\$ Dec 12, 2022 at 13:46
  • \$\begingroup\$ Hi again, I am glad you found an analog-output MEMS mic but the Chinese manufacturer does not know the details of an opamp. The other website with your heartbeat project was down. \$\endgroup\$
    – Audioguru
    Dec 12, 2022 at 18:10

1 Answer 1


It is a single ended output, see just one "OUT" pin, even if they don't explicitly say so. If it were a differential output, there would be an "OUT+" and an "OUT-" pin.

What they have shown is their recommended way to connect to a differential-input amplifier, and to be honest I'm not completely happy with how they show that (there seem to be a lot of unstated assumptions).

I am surprised they didn't show, instead or as well, a simpler recommended connection to a single-ended-input amplifier... like a series DC blocking capacitor going to a the input of an amplifier, pulled to (the amp's) mid-rail by a high value resistor. Signal ground would be shared between the MEMS and the amplifier.


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