Sigma-Delta ADC for Audio Applications

Most of the present cordless and mobile telephony sets and audio multimedia devices are employing an electret microphone as audio input device. These microphones are small, reliable, cheap and have electro-acoustical characteristics well suited for low- to moderate-quality audio applications. The microphones can be manufactured in different sizes, larger diameter devices showing better acoustic sensitivity at the expense of increasing costs, especially when used in mobile phones [41].