Broadband sampling holding circuit used for successive approximation type analog-to-digital converter front-end

Abstract

The invention provides a broadband sampling holding circuit used for a successive approximation type analog-to-digital converter front end. The objective of the invention is to eliminate the defects of an existing sampling holding circuit. The broadband sampling holding circuit is composed of a first-stage voltage buffer, a clock processing unit, a sampling switched capacitor sub circuit and a second-stage voltage buffer; the output end of the first-stage voltage buffer is connected with the input end of the sampling switched capacitor sub circuit controlled by a voltage bootstrapping unit circuit; a signal output end of the sampling switched capacitor sub circuit is connected with a signal input end of the second-stage voltage buffer; and the clock processing unit provides clock signals for the first-stage voltage buffer and the sampling switched capacitor sub circuit respectively. According to the broadband sampling holding circuit of the invention, the broadband-reinforced and clock-controlled first-stage voltage buffer and the second-stage voltage buffer of a PMOS source follower which is used for performing replication unit biasing on N wells are adopted, and therefore, the bandwidth of input sampling signals can be improved, and at the same time, a requirement for signal linearity can be satisfied with extremely low power consumption.

Description

Technical field [0001] The present invention is a field of simulated integrated circuit design technology, which is specific to the broadband sampling maintenance circuit used to approach the front end of the model converter. Background technique [0002] With the development of advanced manufacturing technology of integrated circuits, semiconductor technology has developed to nodes below 20 nanometers.The advancement of the semiconductor process brings the characteristics of low power voltage, low power consumption, high integration, and small chip area to digital circuits; but for simulated circuits, the design of traditional devices has become more complicated and difficult to achieve.Therefore, in the circuit system, the functions that are as many as possible from the simulation domain to the increasingly powerful digital domain to become a research hotspot.Moving a converter is a bridge and bond that builds digital circuits and simulation worlds. It needs to be compatible wi...

AI Technical Summary

Problems solved by technology

However, the traditional successive approximation analog-to-digital converter has an input sampling bandwidth below several hundred MHz

It is difficult to meet the bandwidth requirements of the back-end software radio receiver for ultra-high-speed input signals (above GHz)

Therefore, the bandwidth and power consumption of the sample-and-hold circuit of the existing structure become the bottleneck of the performance improvement of the successive approximation analog-to-digital converter

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