High-linearity input signal buffer applied to high-speed analog-digital converter

Abstract

The invention discloses a high-linearity input signal buffer applied to a high-speed analog-digital converter. The high-linearity input signal buffer is composed of an input driving circuit and is characterized in that the input driving circuit is a source following structure, and nonlinearity of an NMOS source follower is reduced through a linearization enhancement technique. Through a plurality of auxiliary source following circuits, the high-linearity input signal buffer applied to the high-speed analog-digital converter reduces the amplitude of variation of relative voltages among ports of input transistors of the main source follower along with the variation of input signals, and the voltage difference is relatively static, so that the linearity of the main source follower is improved under a large signal input condition.

Description

technical field [0001] The invention relates to the technical field of semiconductor integrated circuits, in particular to an input driving circuit of a data converter circuit. Background technique [0002] Analog-to-digital converters are widely used in modern electronic systems as a bridge for converting analog signals to digital signals. With the development of wireless communication, radar and other systems, the circuit system requires the analog-to-digital converter to have higher conversion rate, higher precision, high input bandwidth, lower power consumption, higher integration and lower cost. [0003] The pipeline analog-to-digital converter can get a more suitable trade-off between conversion rate and conversion accuracy. In order to reduce the power consumption of the circuit as much as possible, the circuit designer combined the traditional sampling and holding circuit with the first-stage pipeline of the pipeline ADC, and omitted the input driver on-chip. For ...

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Problems solved by technology

[0005] However, if a traditional unity-gain negative feedback circuit is used as an input driver, it is basically impossible to implement a unity-gain negative feedback circuit under the given power consumption requirements and large bandwidth input range.

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