Low distortion input buffer for high resolution GS/s rate track-and-hold amplifiers

A novel input buffer for very high speed and high resolution track-and-hold amplifiers has been developed in BiCMOS technology. The configuration retains the benefits of a cascode configuration in terms of distortion and adaptability to various advanced switched-emitter (source)-follower based architectures while maintaining supply requirements similar to a conventional degenerated common emitter amplifier. To demonstrate the advantages of the presented architecture a distortion analysis has been carried out. The closed form formulas show very good agreement with Spectre^® simulations using complete models.