Title :
A CMOS linear preamplifier design for electret microphones
Author :
Park, Gil-Seop ; Ryu, Seung-Tak
Author_Institution :
Sch. of Eng., Inf. & Commun. Univ. (ICU), Daejeon
Abstract :
A gm-opamp-RC configured CMOS linear preamplifier for electret microphone is presented in this paper. The transconductance amplifier (gm-cell), as a V/I convertor at the input stage of the preamplifier, adopts a negative feedback loop at its input pair to enhance the linearity of the output current. Feedback loop improves the SFDR of the preamplifier by 9 dB. Simulated peak signal-to-noise and distortion ratio (SNDR) is 62 dB at 100 mVpp with 2 pF switching capacitor load at 2.56 MHz. The preamplifier operates under 1.8 V supply voltage and the total current consumption is 190 muA. It has been designed for a 0.18 mum CMOS technology.
Keywords :
CMOS analogue integrated circuits; capacitors; electrets; microphones; operational amplifiers; preamplifiers; CMOS linear preamplifier; V/I convertor; electret microphones; gm-opamp-RC configured; negative feedback loop; size 0.18 mum; switching capacitor load; transconductance amplifier; voltage 1.8 V; CMOS technology; Converters; Distortion; Electrets; Feedback loop; Linearity; Microphones; Negative feedback loops; Preamplifiers; Transconductance; Electret capacitor microphone; Linear preamplifier; gm-opamp-RC;
Conference_Titel :
SoC Design Conference, 2008. ISOCC '08. International
Conference_Location :
Busan
Print_ISBN :
978-1-4244-2598-3
Electronic_ISBN :
978-1-4244-2599-0
DOI :
10.1109/SOCDC.2008.4815673
