A reliable full-swing low-distortion CMOS bootstrapped sampling switch

Abstract

A reliable low-distortion CMOS bootstrapped sampling switch is presented. Compared to conventional bootstrapped switch, this scheme achieves more reliability because the limits of proposed circuit are VDD+VTHn and −|VTHp|. The variation of equivalent conductance of this CMOS sampling switch through input signal is alleviated by a specific switch's voltage control. The proposed switch is realized with the half number of transistors compared to previously reported scheme which results more simplicity and less area. Simulations using a standard 0.18μm CMOS technology model show about 10dB improvements in both THD and SFDR while using it in a conventional fully-differential sample-and-hold circuit.