A Simple and Accurate Track-and-Hold Circuit using Operational Transconductance Amplifier

A novel track-and-hold (T&H) employing an operational transconductance amplifier (OTA) with two cross-coupled differential pairs (CCDPs) is proposed for high-accuracy and high-frequency applications. The T&H has a simple architecture requiring smaller capacitors and fewer switches and offers higher speed, lower distortion, and lower power dissipation than its op-amp based counterparts. The chip implemented in 0.35 mum CMOS process operates from a single 1.8 V supply and achieves more than 10-bits precision for sampling rate in excess of 120 MS/s.