Switched capacitor circuit and analog-to-digital converter

Abstract

The invention is suitable for the technical field of signal sampling and provides a switched capacitor circuit and an analog-to-digital converter. The switched capacitor circuit comprises a first driving unit, a first sampling unit, a first sampling and integrating unit and a first operational amplification unit, wherein the first driving unit uses a single-ended input signal as an input signal; the first sampling unit is used for sampling the single-ended input signal during the high level period of a first clock signal; the first sampling and integrating unit is used for sampling a signal of the single-ended input signal output from the first driving unit during the high level period of a third clock signal and integrating a sampling capacitor which is pre-sampled by the first sampling and integrating unit and sampled by the first sampling unit during the high level period of the second clock signal; and the third clock signal, the second clock signal and the first clock signal havethe same period, and high levels of the third clock signal, the second clock signal and the first clock signal appear alternatively in turn in a clock period. Therefore, noise on the sampling capacitor caused by the driving unit is reduced and the effective accuracy is improved.

Description

technical field [0001] The invention belongs to the technical field of signal sampling, in particular to a switched capacitor circuit and an analog-to-digital converter. Background technique [0002] A switched capacitor circuit refers to a circuit composed of switches and capacitors controlled by a clock signal, which uses the storage and transfer of charges to achieve various signal processing functions. [0003] In order to improve the input impedance, the current switched capacitor circuit used in the field of signal sampling generally inserts a drive circuit (BUF) between the input signal and the integrated operational amplifier. However, the introduction of the drive circuit will introduce noise to the switched capacitor circuit at the same time. Thus, the effective precision of signal sampling by the switched capacitor circuit is reduced. Contents of the invention [0004] The purpose of the embodiments of the present invention is to provide a switched capacitor ci...

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Problems solved by technology

[0004] The purpose of the embodiments of the present invention is to provide a switched capacitor circuit, aiming to solve the problem that the effective accuracy of signal sampling is reduced due to the introduction of the drive circuit in the switched capacitor circuit applied to the field of signal sampling provided by the prior art

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