Title :
Audio Pre-Amplifiers for Digital Electret Microphones in 0.18um CMOS Process
Author :
Dec, Aleksander ; Akima, Hiroshi ; Mohn, Russell ; Suyama, Ken
Author_Institution :
Epoch Microelectron., Inc., Tarrytown, NY, USA
Abstract :
This paper presents CMOS audio pre-amplifiers with integrated voltage regulators for digital electret microphones. Several techniques for achieving high input impedance and proper input bias, as well as methods for implementing very low-frequency integrated high-pass filtering are presented. The amplifier with integrated high-pass filter has 14.8 dB of specified voltage gain, 200 muA of current consumption from 2.4 V-3.6 V supply, 60 dB of total harmonic distortion, and 72.8 dB signal to noise ratio at 1 Vpps and 1 kHz output.
Keywords :
CMOS digital integrated circuits; audio-frequency amplifiers; electrets; harmonic distortion; high-pass filters; microphones; preamplifiers; voltage regulators; CMOS audio preamplifier; current 200 muA; current consumption; digital electret microphone; frequency 1 kHz; gain 14.8 dB; integrated voltage regulator; signal to noise ratio; size 0.18 mum; total harmonic distortion; very low-frequency integrated high-pass filter; voltage 2.4 V to 3.6 V; CMOS process; Electrets; Filtering; Filters; Impedance; Microphones; Regulators; Signal to noise ratio; Total harmonic distortion; Voltage;
Conference_Titel :
Circuits and Systems, 2009. ISCAS 2009. IEEE International Symposium on
Conference_Location :
Taipei
Print_ISBN :
978-1-4244-3827-3
Electronic_ISBN :
978-1-4244-3828-0
DOI :
10.1109/ISCAS.2009.5118306
