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Advantages of MEMS microphone
At present, most of the microphones actually used are ECM (electret capacitor) microphones, and this technology has a history of several decades. The working principle of ECM is to use polymer materials with permanent charge to vibrate the membrane.

Compared with the polymer diaphragm of ECM, the performance of MEMS microphone is very stable at different temperatures, and its sensitivity will not be affected by temperature, vibration, humidity and time. Because of its strong heat resistance, MEMS microphone can withstand high temperature reflow soldering at 260℃ without changing its performance. Because the sensitivity changes little before and after assembly, the cost of audio debugging in the manufacturing process can also be saved.

MEMS microphones need external bias provided by ASIC, while ECM does not have such bias. Effective bias will make MEMS microphone keep stable acoustic and electrical parameters in the whole working temperature range, and support microphone designs with different sensitivities.

The size of a conventional ECM is usually larger than that of a MEMS microphone, and it cannot perform SMT (Surface Mount Technology) operations. In the manufacturing process of MEMS microphone, SMT reflow soldering simplifies the manufacturing process and can omit the manufacturing steps that are usually carried out by hand at present.

Electronic components for signal processing must be added to the ECM microphone; In MEMS microphone, only additional special functions need to be added to the microphone. Compared with ECM, the advantage of this extra function is that the microphone has a higher power supply rejection ratio, which can effectively suppress the fluctuation of power supply voltage.

Another advantage is the broadband RF suppression function integrated on the chip, which is particularly important not only for RF applications such as mobile phones, but also for all devices (such as hearing AIDS) with similar working principles to mobile phones.

The small diaphragm of MEMS microphone has another advantage. The small diaphragm with a diameter less than 1mm is also light, which means that MEMS microphone will have lower vibration coupling to PCB noise caused by speakers installed on the same PCB compared with ECM.