Sigma-Delta analog-to-digital converter

Abstract

The invention discloses a Sigma-Delta analog-to-digital converter adopting a novel C type reverser. The Sigma-Delta analog-to-digital converter comprises a Sigma-Delta modulator (52) based on the novel C type reverser, as well as an anti-aliasing filter (50), a sampling holder (51) and a digital extraction filter (53) based on the prior art. In the Sigma-Delta modulator (52), a loop filter (55) is realized by a pseudo-difference structure switched-capacitor integrator based on the novel C type reverser through the single-loop serial mode or the multi-path cascade mode of the prior art; by thebulk potential modulating action of a bulk potential modulator in the novel C type reverser at the input tube body end of the reverser, the adverse effect of the process deviation on the loop filtering accuracy of the analog-to-digital converter is overcome; and under the condition that the power consumption is not obviously increased, the stability and the robustness of the circuit are greatly improved.

Description

technical field [0001] The invention relates to an analog-to-digital converter and belongs to the technical field of integrated circuits. Background technique [0002] At present, with the rapid development of my country's consumer electronics industry and multimedia industry, digital audio technology is developing very rapidly. As an indispensable link, the analog-to-digital converter needs to continue to move towards lower voltage, lower power consumption, lower cost and higher performance. Among them, the low-voltage and low-power consumption design must become the future development of the analog-to-digital converter. One of the main directions. However, the reduction of power supply voltage means the reduction of input common mode range, the reduction of dynamic range, the deterioration of noise and distortion performance, etc., we need to adopt more advanced low power design ideas and more sophisticated circuit design to overcome these difficulties. [0003] The tra...

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Problems solved by technology

[0009] The technical problem to be solved by the present invention is to provide a Sigma-Delta analog-to-digital converter using a new class-C inverter to overcome the fact that the transconductance of the push-pull class-C inverter in the prior art is greatly affected by the process deviation (especially when the size of the MOS tube is large), the deterioration of the integrator's operating frequency, settling time, integration accuracy, and power consumption will seriously affect the accuracy of the analog-to-digital converter loop filter, causing the entire analog Insufficiency of digital converter performance degradation or even loss of function

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