A low noise amplifier suitable for biomedical recording analog front-end in 65nm CMOS technology

This paper presents a fully integrated Front-end, low noise amplifier, dedicated to the processing of various types of bio-medical signals, such as Electrocardiogram (ECG), Electroencephalography (EEG), Axon Action Potential (AAP). A novel noise reduction technique, for an operational transconductance amplifier (OTA), has been proposed. This adds a current steering branch parallel to the differential pair, with a view to reducing the noise contribution by the cascode current sources. Hence, this reduces the overall input referred noise of the Low Noise Amplifier (LNA), without adding any additional power. The proposed technique implemented in 65nm CMOS technology achieves 30dB closed loop voltage gain, 0.05Hz lower cut-off frequency and 100MHz 3-dB bandwidth. It operates at 1.2V power supply and draws 1µA static current. The prototype described in this paper occupies 3300µm2silicon area