identificationmicrophonepinout
Is there any way to "guess" what's the pinout for microphone without damaging it?
Better yet do you know what's the pinout for this? (I have searched on the web but most no site provide schematics. (My guess is there is: Vdd, Gnd, In, Out)
Forgot to add that the part in question does NOT have any reference mark (like it is shown in the picture)
It gives you:
As shown, you get DC feedback via R1+R2. But R1/C1 forms a low pass filter for signals coming from the collector and going to the base. Less negative feedback means less reduction in gain for high frerquencies. Cancel out all those double-negatives and you're left with a high-pass filter.
The transistor below corresponds to Q5 in your drawing.
simulate this circuit – Schematic created using CircuitLab
I think you've misinterpreted the circuit shown on the web page. It applies to any electret. Basically it shorts out only the AC (signal) by using a large capacitor but avoids switching the DC bias voltage which is the source of the pop.
When the mic is plugged in C1 experiences a step voltage (from the 5V supply/R2) which brings both terminals of the capacitor to the DC bias level of the electret.
The negative terminal of the capacitor then discharges through R1 (100k) back to (nearly) 0 volts leaving no voltage across R1 (after more than 5 time constants). From the microphone's perspective it 'sees' a parallel load of 100k (the impedance of the large capacitor being negligible). This is so large it has no effect on the mic's output.
When the mute switch is operated (closed) there is no large DC step because the voltage across R1 is 0V and hence no large POP. The microphone now 'sees' only the 100uF capacitor as a load because the 100k has been shorted out. This effectively shorts out any AC (signal) and hence mutes the mic. The DC bias circuit (R2) is not shorted out because C1 is effectively an open circuit to the DC signal.
Best Answer
It seems that this microphone if from a cell phone. It is hard to tell by the picture whether it is a condenser mic or MEMS mic. My guess it is a condenser microphone.
Usually the largest pad(s) is shield. You can assert this by using a multimeter to check if the two bottom pads are connected (0 ohms).
In case of a condenser mic, the top two pads would be the element.