Dual-voltage-controlled oscillator loop-based Sigma-Delta analog to digital converter

Abstract

The invention discloses a dual-voltage-controlled oscillator (VCO) loop-based Sigma-Delta analog to digital converter which belongs to the technical field of analog integrated circuits, in particular relates to a Sigma-Delta analog to digital converter comprising two VCO loops and a three-order filter. The Sigma-Delta analog to digital converter comprises a three-order low-flux filter with two feedforward branches and a feedback branch, two VCO quantizers, an NRZ DAC (Non Return To Zero Digital to Analog Converter) and an RZ DAC, and an adder-subtractor device. According to the VCO loop-based Sigma-Delta analog to digital converter, through the dual VCO loops, the even harmonics of the VCO are eliminated, the nonlinear distortion is reduced, and the adopted three-order low-flux filter comprising the two feedforward branches and the feedback branch, on the premise of ensuring system stability, the nonlinear distortion and the quantizing noise of the VCO quantizers can be further reduced. The Sigma-Delta analog to digital converter can be suitable for being applied at high speed, higher precision and low power consumption when working at a low power supply voltage.

Description

technical field [0001] The invention belongs to the technical field of analog integrated circuits. It specifically relates to a three-order oversampling (Sigma-Delta) analog-to-digital converter based on a double voltage-controlled oscillator (VCO) loop, which is suitable for high-speed analog-to-digital conversion. Background technique [0002] At present, with the rapid development of the electronics industry and the communication electronics industry, digital signal processing technology is advancing by leaps and bounds. As a bridge from real analog signals to digital signals, analog-to-digital converters need to develop in the direction of higher speed, higher precision, and lower power consumption. Analog-to-digital converters include Nyquist and oversampling (Sigma-Delta) analog-to-digital converters. The clock frequency of the Nyquist analog-to-digital converter is twice the signal frequency, which can include SAR, FLASH, Pipeline, etc. The clock frequency of the ov...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to overcome the shortcomings of high nonlinear distortion and low signal-distortion-to-noise ratio (SNDR) of the Sigma-Delta analog-to-digital converter VCO of a common single VCO loop, and to provide a dual voltage-controlled oscillator (VCO) based Loop Sigma-Delta ADC

Images