A low-noise microsensor amplifier with automatic gain control system

Author

Weng, Jun-Hong ; Yu, Chong-Jng ; Yang, Ching-Yuan ; Yang, Peng-Chang

Author_Institution

Dept. of Electr. Eng., Nat. Chung Hsing Univ., Taichung

fYear

2006

fDate

21-24 May 2006

Lastpage

1413

Abstract

A 0.35-mum CMOS instrumentation amplifier with automatic gain control (AGC) system for the sensor interfaces is presented in this paper. The circuitry employs a chopper stabilization technique to significantly reduce the low-frequency noise and DC offset. The AGC is used in the system where the amplitude of an incoming signal can vary over a wide dynamic range. The AGC circuit provides relatively constant output amplitude in spite of the sensitivity of the sensor due to the parameter variations. Furthermore, the whole system has been kept fully differential operation in order to get higher immunity to environmental noise of supply voltages, clock feedthrough, charge injection, even harmonic distortion, etc. It features a gain of 53plusmn17 dB with 25-kHz bandwidth. The equivalent input noise is about 1.13 muV_pp at 98.2-kHz chopper frequency

Keywords

CMOS integrated circuits; automatic gain control; instrumentation amplifiers; microsensors; 0.35 micron; 25 kHz; 98.2 kHz; CMOS instrumentation amplifier; automatic gain control system; chopper stabilization; low-frequency noise; low-noise microsensor amplifier; sensor interfaces; Choppers; Circuits; Dynamic range; Gain control; Instruments; Low-frequency noise; Low-noise amplifiers; Microsensors; Sensor systems; Working environment noise;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems, 2006. ISCAS 2006. Proceedings. 2006 IEEE International Symposium on

Conference_Location

Island of Kos

Print_ISBN

0-7803-9389-9

Type

conf

DOI

10.1109/ISCAS.2006.1692859

Filename

1692859