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

Volume

02

fYear

2008

fDate

24-25 Nov. 2008

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;

fLanguage

English

Publisher

ieee

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

Type

conf

DOI

10.1109/SOCDC.2008.4815673

Filename

4815673