A Low Noise Amplifier Suitable for Biomedical Recording Analog Front-End in 65 nm CMOS Technology

摘要

This paper presents a fully integrated front-end, low noise amplifier (LNA), 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 LNA, without adding any additional power. The proposed technique implemented in 65 nm CMOS technology achieves 30 dB closed-loop voltage gain, 0.05 Hz lower cut-off frequency and 100 MHz 3-dB bandwidth. It operates at 1.2 V power supply and draws 1 mu A static current. The prototype described in this paper occupies 3300 mu m(2) silicon area.