Electret condenser microphone (ECM microphone) apply the principle of capacitor charge/discharge for operation. The diaphragm acts as one plate of a capacitor, the vibration is generated due to the sound, then produce the changes of charge between the plates to make the signal transmission.
Since the vibration is purely an electromechanical mechanism, it has the whole acoustic frequency response (0-20kHZ) and low distortion in the signal transmission, generally used in external portable microphone. Its shortcoming is being unable to undertake a re-flow soldering, so there is a specific soldering process and tools for manual soldering.
MEMS microphone is a product of semiconductor technology. It has some significant advantages over ECMs in their performance, reliability, and manufacturability, namely as the following points:
- MEMS microphone can be undertaken re-flow soldering process, but ECM cannot.
- MEMS microphones have a higher “Performance Density” than ECM, meaning that MEMS microphones have better noise performance than ECM at the dimension, i.e. the noise of MEMS microphones can be assessed and cancelled.
- Under the temperature changes, MEMS microphone has less sensitivity variation than ECM. Normally, ECM sensitivity drifts up to +/- 4 dB over its operating temperature range, but there is about 0.5 db under the MEMS microphones.
- MEMS microphones have a lower vibration sensitivity than ECM. Because the mass of MEMS microphones are generally lower than that of ECM, the vibration response is less affected than ECM.
- MEMS microphones have more uniform part-to-part frequency response than ECMs. There was a random selection where samples were picked from each type and put through frequency response analysis, especially in the high frequency and low frequency performance. This experiment shows that MEMS microphones have a more stable and average results, which means that the final product using MEMS will have a more stable performance.
Since MEMS microphone have many advantages, it is used in many aspect of products such as smart phones, tablet PCs, hearing aids, cars, headphones, smart home and so on.
You can find our microphones here and you can choose Electret Condenser or MEMS in Type.