A 828μW 1.8V 80dB dynamic-range readout interface for a MEMS capacitive microphone

Author

Jawed, S.A. ; Cattin, D. ; Gottardi, M. ; Massari, N. ; Baschirotto, A. ; Simoni, A.

Author_Institution

MIS Div., Fondazione Bruno Kessler, Trento

fYear

2008

fDate

15-19 Sept. 2008

Firstpage

442

Lastpage

445

Abstract

A CMOS interface for a piston-type MEMS capacitive microphone is presented. It performs a capacitance-to-voltage conversion by bootstrapping the sensor through a voltage pre-amplifier, feeding a third-order sigma-delta modulator. The bootstrapping performs active parasitic compensation, improving the readout sensitivity by ~12 dB. The total current consumption is 460 uA at 1.8 V-supply. The digital output achieves 80 dBA-DR, with 63 dBA peak-SNR, using 0.35 um 2P/4M CMOS technology. The paper includes electrical and acoustic measurement results for the interface.

Keywords

CMOS integrated circuits; bootstrap circuits; micromechanical devices; microphones; preamplifiers; readout electronics; sigma-delta modulation; 2P/4M CMOS technology; CMOS interface; MEMS capacitive microphone; acoustic measurement; bootstrapping; capacitance-to-voltage conversion; dynamic-range readout interface; electrical measurement; power 828 muW; size 0.35 mum; third-order sigma-delta modulator; voltage 1.8 V; voltage pre-amplifier; Acoustic sensors; CMOS technology; Capacitive sensors; Diodes; Mechanical sensors; Micromechanical devices; Microphones; Parasitic capacitance; Resistors; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State Circuits Conference, 2008. ESSCIRC 2008. 34th European

Conference_Location

Edinburgh

ISSN

1930-8833

Print_ISBN

978-1-4244-2361-3

Electronic_ISBN

1930-8833

Type

conf

DOI

10.1109/ESSCIRC.2008.4681887

Filename

4681887