10-Bit Video BiCMOS Track-and-Hold Amplifier.

摘要

A 1.2-micron BiCMOS technology has been used to implement a monolithic video track-and-hold amplifier that settles to an accuracy of 10 bits in 15 ns. This level of performance is competitive with hybrid track-and-hold circuits and surpasses previously reported monolithic implementations by nearly two orders of magnitude. The amplifier's design is based on a closed-loop topology incorporating two BiCMOS folded-cascode gain stages, and NMOS sampling switch, and a BiCMOS switch driver with 1-ns transitions between + or -4 V. The circuit operates from + or -5-V power supplies and is capable of driving a 50-ohms load with + or -1-V swings. For a fully differential implementation, the power dissipation is 1.2 W. The amplifier can be integrated either as a stand-alone track-and-hold circuit or as the front end of an analog-to-digital conversion system for video and high-speed instrumentation applications. Reprints. (sdw)