论文信息 - A low-noise/low-power preamplifier for capacitive microphones

A low-noise/low-power preamplifier for capacitive microphones

A design for a microphone preamplifier for application in hearing aids is presented. The amplifier operates at a supply of 1-1.5 V, the current drain is 40 /spl mu/A. The maximum sound level allowed is more than 120 dB SPL (Sound Pressure Level), with a typical noise level of 25 dB(A) SPL (A-weighted). The amplifier is optimized for a capacitive microphone with a capacitance of 1.2 pF. The amplifier is fully integrated in a 0.7 /spl mu/m n-well CMOS technology. Design details concerning noise performance are analytically described.

C.E. Furst

[1] A. Abidi,et al. Flicker noise in CMOS transistors from subthreshold to strong inversion at various temperatures , 1994 .

[2] W. Guggenbuhl,et al. A versatile building block: the CMOS differential difference amplifier , 1987 .

[3] Willy M. C. Sansen,et al. Low-noise wide-band amplifiers in bipolar and CMOS technologies , 1990, The Kluwer international series in engineering and computer science.

[4] E. Vittoz,et al. An analytical MOS transistor model valid in all regions of operation and dedicated to low-voltage and low-current applications , 1995 .

[5] L.K.J. Vandamme,et al. 1/f noise in MOS devices, mobility or number fluctuations? , 1994 .

[6] A. C. Pluygers. A novel microphone preamplifier for use in hearing aids , 1993 .

[7] Mohammed Ismail,et al. A wide range differential difference amplifier: a basic block for analog signal processing in MOS technology , 1993 .

[8] Lode K. J. Vandamme,et al. Noise as a diagnostic tool for quality and reliability of electronic devices , 1994 .

[9] José E. Franca,et al. Design of Analog-Digital VLSI Circuits for Telecommunications and Signal Processing , 1993 .