|
|||||
|
|
Low‐Noise MEMS Microphone Readout Integrated Circuit Using Positive Feedback Signal Amplification |
|
| Authors: | Yi‐Gyeong Kim Min‐Hyung Cho Jaewoo Lee Young‐Deuk Jeon Tae Moon Roh Chun‐Gi Lyuh Woo Seok Yang Jong‐Kee Kwon |
| Abstract: | A low‐noise readout integrated circuit (ROIC) for a microelectromechanical systems (MEMS) microphone is presented in this paper. A positive feedback signal amplification technique is applied at the front‐end of the ROIC to minimize the effect of the output buffer noise. A feedback scheme in the source follower prevents degradation of the noise performance caused by both the noise of the input reference current and the noise of the power supply. A voltage booster adopts noise filters to cut out the noise of the sensor bias voltage. The prototype ROIC achieves an input referred noise (A‐weighted) of ?114.2 dBV over an audio bandwidth of 20 Hz to 20 kHz with a 136 μA current consumption. The chip is occupied with an active area of 0.35 mm2 and a chip area of 0.54 mm2. |
| Keywords: | Microelectromechanical systems microphone capacitive microphone positive feedback signal amplification source follower voltage booster MEMS |
