Integral analog-to-digital converter

Abstract

The invention provides an integral analog-to-digital converter which comprises a buffer, an integrator, a comparing module and a self-zeroing auxiliary circuit, wherein the buffer is used for increasing a driving force of an input signal and a reference signal of the analog-to-digital converter; the integrator is used for integrating the output signal of the buffer; the comparing module is used for comparing the output voltage of the integrator with a reference voltage so as to generate a marking signal; the self-zeroing auxiliary circuit is used for eliminating offset voltages of the buffer, the integrator and the comparing module during a self-zeroing period. By storing the offset voltages into an integrating capacitor and a self-zeroing capacitor, the offset voltages of the buffer, the integrator and the comparing module are eliminated, no extra frequency compensating circuits need to be added during the realization process, and the complexity and the design difficulties of circuits are reduced significantly.

Description

technical field [0001] The invention relates to the technical field of analog-to-digital conversion, in particular to an integral analog-to-digital converter. Background technique [0002] Many applications require the conversion of continuous analog signals to discrete digital signals. ADC design typically involves a tradeoff between resolution (the number of discrete levels contained in a digitized signal) and speed (the number of samples that can be sampled per second). [0003] In practical applications, the integrating ADC has the characteristic that it is not affected by the process change of the integrating resistor and integrating capacitor, but its accuracy will be affected by the offset voltage of the buffer op amp, the offset voltage of the integrating op amp, and the offset voltage of the comparator. In order to achieve high precision, it must Eliminate these offset voltages, so the integral ADC must go through auto-zero before each conversion, in order to be ap...

AI Technical Summary

Problems solved by technology

However, the requirements of the first three points often make the last point difficult to achieve

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