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AC Coupled Pseudo Differential Input

Question asked by CSB on May 22, 2014
Latest reply on May 25, 2014 by JinoL

Hi,

 

I have a differential input, differential output amplifier being driven by a single ended output microphone. Here is the circuit -

 

Circuit.png

The output is noisy and I suspect it has something to do with both inputs being AC coupled.

The Microphone has a DC output of 1V, hence the AC coupling.

If I short out C9 so that the inverted input of the amplifier is directly coupled to GND, the noise goes away. However this give me a permanent differential voltage on the input of 1V.

 

Is there a correct way to AC couple pseudo differential output to a differential input?

Thanks

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