Front-end sampling circuit with buffer

Abstract

The invention provides a front-end sampling circuit with a buffer. The front-end sampling circuit comprises a sampling module, a bootstrap switch, a driving module, a buffer module and a bias module; the driving module comprises a first connecting end and a second connecting end, and the sampling module comprises an input end, an output end and an offset end; the buffer module comprises an input end, an output end and a third connecting end; the first connecting end is connected with one end of the bootstrap switch, and the other end of the bootstrap switch is connected with the offset end of the sampling module; the input end of the buffer module is in butt joint with an input signal, and the output end of the buffer module is respectively connected with the second connecting end, one end of the bias module and the input end of the sampling module; the third connecting end is connected with the first connecting end; and the other end of the bias module is grounded. According to the invention, the linearity of the sampling network can be effectively improved.

Description

technical field [0001] The invention relates to the field of analog integrated circuits, in particular to a front-end sampling circuit with a buffer. Background technique [0002] The existing technology either adopts a switched capacitor sample-and-hold structure, or adopts a switched capacitor hold structure with a buffer at the front end. Both of these methods need to be designed with a bootstrap switch structure. If you look at it, you will see additional bootstrap capacitors, as well as sampling capacitors, which will increase the difficulty of input driving. A bootstrap switching circuit with a front-end buffer, on the other hand, sees a bootstrap capacitor and sampling capacitor at the output of the buffer, which will load the buffer and affect the linearity of the sampling network. In order to reduce the size of the driving capacitance seen by the input buffer and improve the linearity of the buffer input tube, the present invention adopts an additional bias network...

AI Technical Summary

Problems solved by technology

[0003] In view of the above existing problems in the prior art, the present invention proposes a front-end sampling circuit with a buffer, which mainly solves the problem that the existing buffer load is too heavy to affect the sampling linearity

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