Title :
A low-noise/low-power preamplifier for capacitive microphones
Author :
Fürst, Cluus Erdmann
Author_Institution :
Dept. of Inf. Tech., Tech. Univ., Lyngby, Denmark
Abstract :
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 μA. 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 μm n-well CMOS technology. Design details concerning noise performance are analytically described
Keywords :
CMOS analogue integrated circuits; audio-frequency amplifiers; capacitance; hearing aids; integrated circuit noise; microphones; preamplifiers; 0.7 micron; 1 to 1.5 V; 1.2 pF; 25 dB; 40 muA; capacitive microphones; hearing aids; low-noise preamplifier; low-power preamplifier; microphone preamplifier; n-well CMOS technology; Acoustic noise; Electrets; FETs; Leakage current; Microphones; Noise level; Preamplifiers; Resistors; Signal to noise ratio; Voltage;
Conference_Titel :
Circuits and Systems, 1996. ISCAS '96., Connecting the World., 1996 IEEE International Symposium on
Conference_Location :
Atlanta, GA
Print_ISBN :
0-7803-3073-0
DOI :
10.1109/ISCAS.1996.539988
