A 1 Gsample/s 8 b silicon bipolar track and hold IC

Abstract

High-performance data acquisition systems like digitizing oscilloscopes require both high sample rates and fine resolution, two competing requirements. A track-and-hold (TH) circuit is a key component of such systems. So far, there is no silicon bipolar TH IC for 1 Gsample/s with 8 b linearity. Even with modern GaAs processes this performance has not yet been surpassed. This TH is fabricated in a silicon bipolar production process, featuring a low component count, all-npn transistor design, 460 mW power consumption (excluding the test buffer), and less than 62.4 dB total harmonic distortion (THD), corresponding to 8.4 b linearity, up to 1.2 Gsample/s over the full Nyquist band. This TH is suitable as an on-chip subcomponent for 1 Gsample/s 8 b silicon integrated analog-to-digital converter (ADC) systems, such as full flash or pipeline ADCs.