Design of a linearized operational transconductance amplifier using quasi-floating bulk resistor

Linearity of the operational transconductance amplifier (OTA) is the key parameter that affects its overall performance when used in health care applications. However, achieving high linearity with low-power operation at low supply voltages is challenging issue in CMOS technology. In this work, we have proposed a cross-coupled bulk linearization technique-based OTA using quasi-floating bulk resistor in 0.18 µm standard CMOS process which works at low-supply voltage of ± 0.5 V. The proposed OTA shows transconductance of 589 nS for low frequencies (0.1 Hz to 100 Hz), dc-gain of 39.9 dB, gain-bandwidth (GBW) of 0.608 MHz, common mode rejection ratio (CMRR) of 88.89 dB, total harmonic distortion (THD) of -39.42 dB and power consumption of 0.498 µW. The proposed linearized OTA consumes area of 20443.05 µm2. The proposed linearized OTA is expected to be used in various analog circuits for health care applications.