Low-offset Sigma-delta modulator with adjustable input range

Abstract

The invention relates to the technical field of digital signal processing, and particularly discloses a low-offset Sigma-with an adjustable input range. The delta modulator comprises an input signal sampling module, a first reference voltage sampling module, a second reference voltage sampling module, a first input signal range adjusting module, a second input signal range adjusting module, an integration module and a comparison module, wherein the input signal range adjusting module I and the input signal range adjusting module II are respectively connected with the input signal sampling module; the input signal sampling module is connected with the integration module, the integral module is connected with the comparison module; the two ends of the first reference voltage sampling moduleare connected with the integration module and the comparison module respectively, the two ends of the second reference voltage sampling module are connected with the integration module and the comparison module respectively, a PGA circuit does not need to be additionally arranged, the area and the effect of a chip can be effectively saved, and the low-offset characteristic is achieved.

Description

technical field [0001] The invention relates to the technical field of digital signal processing, in particular to a low offset Sigma-delta modulator with adjustable input range. Background technique [0002] With the rapid development of science and technology, digital signal processing technology is more and more widely used in various fields of science and daily life. The signals processed by the digital system are digital signals, but the signals in nature, such as temperature, pressure, speed, sound, etc., which are often used in industrial detection control and daily life, are all continuously changing analog signals. In order to enable the digital system to process these analog signals, it is necessary to realize the mutual conversion between analog and digital, and the analog-to-digital converter (ADC) has become a key component in the connection between the analog system and the digital system. [0003] Common ADC structures are Nyquist rate ADC and oversampling AD...

AI Technical Summary

Problems solved by technology

Since each natural analog signal has its own amplitude range, the signal amplitude after passing through the front-end low-noise op amp or the charge integrator will also have a large difference

The common Σ-Δ ADC has a fixed quantization input range, so the signal after initial amplification needs to be adjusted by a programmable gain amplifier (PGA) before being passed to the ADC, but this structure needs to add a PGA circuit, which requires An additional operational amplifier and sampling, feedback capacitors, and sampling switches increase circuit complexity, power consumption, and area

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