Design of a Gm-C Dynamic Amplifier with High Linearity and High Temperature and Power Supply Voltage Stability

Abstract: This paper presents a Gm-C dynamic amplifier with high linearity and high temperature and power supply voltage stability. The main part of the amplifier employs two asymmetric differential pairs to enhance transconductance linearity. The amplifier maintains a nearly constant gain within a differential input range of -40 mV to 40 mV, and achieves a total harmonic distortion (THD) of 70.5 dB. The bias part of the amplifier adopts a constant-gm bias circuit, which improves the temperature and supply voltage stability of the amplifier's transconductance and gain. When the differential input is 1 mV, the power supply voltage fluctuates by $\pm$10%, and the temperature varies between -40$\mathrm{^\circ C}$ and 120$\mathrm{^\circ C}$, the standard deviation of the gain distribution is 262m, and the distribution range is from 15.1 to 16.3.