Sampling hold circuit applied to analogue-to-digital converter

Abstract

The invention discloses a sampling hold circuit applied to an analogue-to-digital converter, which comprises a sampling switch bootstrap circuit (10), a sampling network (20) and a source follower (30). The output end of the sampling switch bootstrap circuit (10) is connected with the input end of the sampling network (20); the output end of the sampling network (20) is connected with the input end of the source follower (30); and a thirteenth node (13) of the source follower (30) is the output Vout of the sampling hold circuit. Compared with the conventional sampling hold circuit, the sampling hold circuit applied to the analogue-to-digital converter eliminates the nonlinearity of a switch conducting resistance, reduces signal distortion and improves the accuracy of the circuit due to theadoption of the bootstrap circuit.

Description

technical field [0001] The invention relates to the technical field of sample and hold (Track and Hold) circuits, in particular to a sample and hold (Track and Hold) circuit including a bootstrap circuit applied to an analog-to-digital converter. Background technique [0002] A sample-and-hold circuit (sample / hold) is also called a sample-and-hold amplifier. General sample and hold circuits are implemented using switched capacitor circuits. A switched capacitor circuit is a circuit consisting of switches and capacitors controlled by a clock signal. It uses the storage and transfer of charges to realize various processing functions of signals. In actual circuits, sometimes circuits composed of only switches and capacitors often do not meet the requirements, so they are often combined with amplifiers or operational amplifiers, comparators, etc. to realize the generation, conversion and processing of electrical signals. [0003] figure 1 for a basic switched capacitor ampli...

AI Technical Summary

Problems solved by technology

On the one hand, the op amp is not an ideal op amp, and there is a gain error; on the other hand, since the sample-and-hold circuit is a switched capacitor circuit, its own switch charge injection effect and clock feedthrough, as well as the on-resistance of the switch Non-linearity will affect the accuracy of the sample and hold circuit

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