CMOS Digitally Programmable Lock-In Amplifier for Bio Applications

ISBN-13: 9786200005380 / Angielski

Samah Milhem; Soliman Mahmoud

Opis

This work proposes a new EEG detection system based on a CMOS lock-in amplifier with programmable gain. The proposed lock-in amplifier consists of five stages: the first and fourth stages are 4-quadrant multipliers with a gain of 8 dB, the second stage is made of two cascaded programmable instrumentation amplifiers (IA), while the third stage is a band-pass filter (BPF) centered at 1 kHz with a gain of 7 dB, and the last stage is a low pass filter (LPF) with a gain of 30 dB and a bandwidth of 150 Hz. A basic building block is the digitally programmable balanced output operational transconductance amplifier (DPOTA), which is used in this work to realize the filters and the IA using 0.25-µm CMOS technology. The proposed lock-in amplifier is characterized by a wide programmable gain ranging from 48dB to 92dB, low power consumption of 71 µW at the maximum gain setting, and low input referred noise of 383nV/ Hz @ 20Hz. PVT and Monte Carlo simulations are also carried out to show the robustness of the proposed lock-in amplifier as a good candidate for EEG detection systems.

O autorze

Milhem, SamahSoliman A. Mahmoud received the BSc degree with honors in 1994, the MSc degree in 1996, and the PhD degree in 1999, all from the Electronics and Communications Department, Cairo University, Egypt. He is Professor and the department chairman at the Electrical and Computer Engineering Department, University of Sharjah, Sharjah, UAE.