A High Linear CMOS Body Effect Compensation Bootstrapped Switch

Abstract

This paper presents a new bootstrapped switch with high speed and low nonlinear distortion. Instead of fixed voltage, the gate-to-source voltage of switch varies with input to implement first-order body effect compensation. Post-layout simulations have been done in standard 0.18-μm CMOS process at 1.8 V, and results indicate that at 200 MHz sample rate, a peak signal-to-noise-and-distortion ratio (SNDR) of 98.4 dB, spurious-free dynamic range (SFDR) of 105.7 dB and total harmonic distortion (THD) of -104.9 dB can be acquired. For input frequency up to the 60 MHz frequency, proposed structure maintains |THD| over 85 dB, SFDR better than 86 dB, respectively.