A power efficient low-noise source degenerated bio-potential amplifier

• Published in: Analog integrated circuits and signal processing Vol. 103; no. 2; pp. 291 - 301
• Main Authors: Venishetty, Sudheer Raja, Kumaravel, S., Durai, S. Ananiah
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.05.2020; Springer Nature B.V
• Subjects: Circuits and Systems; Degeneration; Electrical Engineering; Engineering; Noise reduction; Operational amplifiers; Power consumption; Signal,Image and Speech Processing; Simulation; Transconductance; Transistors; CMRR; Operational transconductance amplifier; Noise efficiency factor; PSRR; Source degeneration; Low noise amplifier; Bio-potential amplifier; Sub-threshold
• ISSN: 0925-1030; 1573-1979
• DOI: 10.1007/s10470-020-01628-7

In literature double recycling folded cascode operational transconductance amplifier (DRFC-OTA) is realized to achieve higher transconductance. To realize preamplifier for bio-medical applications, it is necessary to design an OTA with lower noise. In this paper source degeneration is adopted for DRFC-OTA for further reduction of noise and is proposed. To access the efficacy of this technique, the preamplifier using DRFC-OTA with source degeneration (DRFCSD) is realized in UMC 180 nm technology and is studied through simulations. For sizing the transistors of DRFCSD, g m / I D methodology is adopted. From the simulation results it is observed that, the preamplifier exhibits a mid-band gain of 40.02 dB at − 3 dB bandwidth of 5.69 Hz–5.45 kHz. The total input referred noise of amplifier is found to be 3.27 μ V rms for 5.69 Hz–5.45 kHz for a power consumption of 1.53 μ W . The noise efficiency factor is found to be 1.58 and provides an output swing of 1.2 V pp at THD of 1 %. CMRR and PSRR of the preamplifier are simulated and found to be 66.55 dB and 54.99 dB respectively. The amplifier occupies an area of 0.16 mm 2 .