I want to interface two electret microphones with a stereo audio codec. One mic will capture audio from one side of a box and the other one from the opposite side. I want to use TLV320AIC3254 from Texas Instruments (Stereo Audio Codec).
My microphones have two terminals (+ and -) that I will connect to the corresponding adaptation circuit for electret microphones (one resistor and two capacitors). After this, I will have one electrical point to interface (the signal itself). How can I connect that point to the Stereo Audio Codec? In the scheme I can read IN1, IN2, IN3 and L and R each.
Let's think my right microphone is IN1, I will connect it to IN1_R, what should I connect to IN1_L? Should I connect the other mic there? Should I connect it to GND and connect the left mic in IN2_L?
As a summary, I don't know why there are three pairs of L-R connections in the codec pinout and how to interface them with just two microphones.