Date: 05/03/2010

World's smallest MEMS microphones with a digital interface

TDK-EPC claims to have made available world's smallest commercially available MEMS microphone with an integrated digital interface. The dimensions of the EPCOS T4030 of only 3.25 × 2.25 × 1.1 mm³ make the microphone about 60 percent smaller than alternative products. This small size helps in saving space in mobile phones and consumer electronics applications such as MP3 players and digital cameras.

The T4030 has a sensitivity of -26 dB FS (full scale), and a signal-to-noise ratio of 60 dBA. At a sound level of 100 dB this microphone maintains distortion factor under 1 percent. Its frequency response is characterized by high bandwidth and low amplitude fluctuations. The T4030 is largely insensitive to electromagnetic interference due to a digital PDM (pulse density modulation) output. The suppression of the power supply noise is -82 dB FS. Two channels can also be transmitted via one signal line, making stereo applications much simpler to implement than in analog technology. The supply voltage range is between 1.64 and 2.86 V. The power consumption is 650 µA and is reduced to less than 10 µA in standby operation.

The microphone is also suggested for applications with high requirements on audio quality. This also includes high-quality video and VoIP (Voice over IP) systems, telephone conference installations, beam-forming and noise-suppression systems.

The T4030 is manufactured in the CSMP (chip-sized MEMS package) technology, which was developed for SAW filters and has already used in billions of mobile phones.