This is a high quality CUI CMC-2742PBJ-A omnidirectional miniature 6mm condenser microphone with PCB leads
- Condenser Microphone CUI CMC-2742PBJ-A
KEY FEATURES OF MICROPHONE CONDENSER 6MM:
- 100 Hz – 20 kHz frequency range
- -42dB +/- 3dB sensitivity
- 2-10VDC operating voltage
- 2.2kOhm output impedance
This is a miniature condenser microphone that is used for converting acoustical energy (sound) into electrical energy. Condenser is the old term for capacitor and these microphones use a capacitor type construction to detect sound. When sound waves hit the microphone diaphragm, it changes the distance of the two capacitor plates and therefore the capacitance which in turn changes the electrical output of the microphone . Condenser mics are more sensitive and have greater dynamic range than similar dynamic microphones.
Condenser microphones are powered, so they require a working voltage of 2V – 10V along with a couple of external components including a load resistor and a capacitor to AC couple the output.
This microphone has two 2.8mm long PCB terminals on the back.
Terminal 1 is the output and is connected to the power source via a resistor with a value of 2.2K.
A series capacitor with a value of 1uf – 10uF or so is placed on the output. This output is typically fed into an audio amplifier of some type to boost the signal.
Terminal 2 is connected to the system ground.
Our Evaluation Results:
These mics work very well for adding sound detection to a project. The pins are on the short side so the parts are marginally breadboard compatible. The pins can be lengthened by soldering on a little wire if needed.
Below is a scope capture using the circuit shown in the schematic. Power to the mic is 5V and the scope is set for 10mV/div. Input is a whistle
|-42dB ± 3dB
|2V typical, 10V max
|Dia x H
|6 x 2.7mm (0.24 x 0.1″)