Device and method for holding sampling

Abstract

The invention discloses a sample-and-hold amplifier which comprises a primary sample-and-hold circuit and a secondary sample-and-hold circuit. The input positive terminal and the input negative terminal of the primary sample-and-hold circuit receive an external signal, the output positive terminal and the output negative terminal of the primary sample-and-hold circuit are coupled to the input positive terminal and the input negative terminal of the secondary sample-and-hold circuit, the primary sample-and-hold circuit is provided with a primary operational amplifier with the amplification being less than a multiple, and the secondary sample-and-hold circuit is provided with a secondary operational amplifier which realizes the amplification more than the multiple; after the external signal is sampled, held and amplified, by the primary sample-and-hold circuit and the secondary sample-and-hold circuit, the external signal is output from the output positive terminal and the output negative terminal of the secondary sample-and-hold circuit. Meanwhile, the invention discloses a sample-and-hold method. The sample-and-hold amplifier, as a basic signal processing module, is used for front end processing of the external input signal; and the sample-and-hold amplifier ensures the speed and the precision of the signal conversion with the simple structure on the premise of realizing high reliability.

Description

【Technical field】

[0001] The invention relates to analog and digital signal processing, in particular to a sample-and-hold device and a sample-and-hold method. 【Background technique】

[0002] A sample-and-hold circuit (sample-and-hold) is also called a sample-and-hold amplifier. When the analog / digital conversion is performed on the analog signal, a certain conversion time is required. During this conversion time, the analog signal should remain basically unchanged, so as to ensure the conversion accuracy. The sample and hold circuit is the circuit that realizes this function.

[0003] Figure 1a Shown is a traditional sampling and holding circuit, in which the capacitor Cs is both a sampling capacitor and a holding capacitor. When in the sampling phase (sampling time), the switch controls the input and output of the operational amplifier to short-circuit, and the two inputs are also short-circuited at the same time, the switch connected to the external signal is turned on...

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