Microphone input circuit design problems

How to convert a single-ended microphone into a differential microphone input? Thank you!

 

Which one do you want?

 

The mic end of the false difference is grounded at the other end, and the signal at both ends of the resistance is collected to form the false difference.

The real difference is that the two ends of the MIC pull a bias and then input to the differential input.

Unfortunately, I won't draw pictures.

 

Both true and false differences have the same effect

 

However, wiring is exquisite.

1. Real Difference

The microphone offset power supply goes through a resistor R1 to the microphone positive pole, the microphone negative pole goes through a resistor R2 to the ground, and the two ends of the microphone are separated by a capacitor until the Op Amplifier is de-amplified. R1 = R2.
2. False difference

The microphone bias power is powered by a resistor R1 to the microphone positive, and the microphone negative grounding. The positive and negative ends of the microphone (in fact, the ground) are separated by Capacitance until the Op Amplifier is de-amplified.

Pay attention to wiring and power supply filtering, otherwise it will not work.

I am a single-ended mic input, while the codec interface is a double-ended (I .e., differential) input! In this way, how can I connect?

The ground wire of the single-ended mic is directed to the negative input of the difference through the direct capacitor. This eliminates ground noise.