High sampling rate broadband track and hold circuit

Abstract

The invention discloses a high-sampling-rate broadband track and hold circuit and relates to the technical field of electrons. The track and hold circuit comprises an input buffer unit IB, a track / hold switch T / H, a holding capacitor CH and an output buffer unit OB. A full-differential circuit structure is introduced to realize good common-mode noise suppression ability; through the input and output buffers having emitter degeneration resistors, linearity of the track and hold circuit is improved; an improved switch emitter follower having a Schottky diode is adopted as a track and hold switch, so that circuit stability is improved; and the track and hold circuit is designed by utilizing a GaAs HBT device having high cut-off frequency and good base-emitter match, thereby solving the defects of low sampling rate and narrow bandwidth of an existing sampling and hold circuit.

Description

Technical field [0001] The invention relates to the field of electronic technology, in particular to a high-sampling-rate broadband tracking and holding circuit. Background technique [0002] Track-and-hold amplifiers can track or maintain the level of the input analog signal, and are often used as a key component of the analog-to-digital converter (ADC). The track-and-hold amplifier is composed of a sampling switch with a holding capacitor. In the tracking mode, its output tracks the input signal. When the track-and-hold switch is turned on, its output remains constant. In order to accurately digitize the signal, most analog-to-digital converters need to add a track-and-hold amplifier at the input. The introduction of the track-and-hold amplifier improves the dynamic performance of the analog-to-digital converter, and it suppresses the drop in the spurious-free dynamic range index caused by the clock aperture jitter. Especially in the ultra-high-speed analog-to-digital converte...

AI Technical Summary

Problems solved by technology

[0006] In order to overcome the above-mentioned problems in the prior art, the GaAs HBT-based high-sampling-rate broadband track-and-hold circuit solves the instability caused by the traditional switch emitter follower (SEF) structure driving a large capacitor, and aims to improve the track-and-hold circuit sampling rate and bandwidth

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