Low Noise Amplifier for Health Monitoring

This paper presents a low-noise low-power operational amplifier circuit to amplify bio-medical signals at low frequency. Complementary based differential input technique with large transistor is used to reduce the input referred noise. Class-AB technique is used at the output stage to increase the voltage swing and to enhance the gm/I D efficiency. Control circuitry of class-AB structure is fixed into the differential stage to minimize the power consumption. SCL-PDK library at 180nm is used to analyze the amplifier circuit. The proposed circuit reduces the noise and power consumption of the amplifier by 44% and 72% with increase of gain-bandwidth product by 8% at the cost of reduced ICMR by 4% when compared to recently reported amplifiers.