A Low Power Cmos Analog Circuit Design for Acquiring Multichannel Eeg Signals

EEG signals are the signatures of neural activities and are captured by multiple-electrodes and the signals are recorded from pairs of electrodes. To acquire these multichannel signals a low power CMOS circuit was designed and implemented. The design operates in weak inversion region employing sub threshold source coupled logic. A 16 channel differential multiplexer is designed by utilizing a transmission gate with dynamic threshold logic and a 4 to 16 decoder is used to select the individual channels. The ON and OFF resistance of the transmission gate obtained is 27 ohms and 10 M ohms respectively. The power dissipation achieved is around 337nW for a dynamic range of 1μV to 0.4 V.