Sigma-Delta modulator and Sigma-Delta analog to digital converter comprising same

Abstract

The invention provides a low circuit sensitive Sigma-Delta modulator capable of increasing the input signal scope and improving the precision, which comprises a first analog subtractor, a first gain unit, at least one auxiliary quantizer, a second gain unit, a second analog subtractor, a internal Sigma-Delta modulation module, a shift register, a digital subtractor and a feedback digital to analog converter (DAC). The Sigma-Delta modulate not only reduces sensitivity to imperfection of assemblies, but also greatly improves input signal level while improving the precision.

Description

technical field [0001] The present invention relates to the technical field of integrated circuits for analog-to-digital converters and signal processing, in particular to a Sigma-Delta modulator capable of increasing input signal range, improving precision and reducing non-ideal requirements for components and including the modulator Sigma-Delta ADC. Background technique [0002] Based on oversampling and noise shaping techniques, Sigma-Delta analog-to-digital converters (ADCs) have been widely used in low-to-high bandwidth, high-precision, low-voltage and low-power communication systems. A basic sigma-delta ADC includes a front-end anti-aliasing filter to filter out-of-band input signals, a sigma-delta modulator (SDM) to push line noise and quantization noise to high frequencies, and a back-end to filter high Frequency noise, digital filters that reduce the sampling frequency, among which the Sigma-Delta modulator plays a decisive role in the performance of the entire ADC...

AI Technical Summary

Problems solved by technology

However, this structure requires very high-precision analog lines to precisely match the analog and digital filters, which results in high power consumption

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