Differential input hysteresis comparator with precisely adjustable hysteresis window and working method

Abstract

The invention discloses a differential input hysteresis comparator with a precisely adjustable hysteresis window. The differential input hysteresis comparator comprises a digital-to-analog converter module, a first differential pair unit, a second differential pair unit, a current adder module and a current-to-voltage conversion module, the input end of the digital-to-analog converter module is connected with an input control signal, the output end of the digital-to-analog converter module is connected with the second differential pair, the input end of the first differential pair is connected with a to-be-compared input signal, and the output end of the first differential pair and the output end of the second differential pair are respectively connected with the input end of the current adder module; and the output end of the current adder module is connected with the current-voltage conversion module. According to the hysteresis comparator provided by the invention, the size of the hysteresis window can be accurately adjusted, the voltage of the hysteresis window is accurately generated by a digital-to-analog converter, and the size of the window can be controlled one by one by digital codes.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, in particular to a differential input hysteresis comparator with an accurately adjustable hysteresis window and a working method. Background technique [0002] In recent years, comparators have become one of the most important components in analog integrated circuits. The comparator can compare the input signal with a defined reference voltage and output a logic high or logic low level, thereby converting the input analog signal into a binary digital signal. The logic output function of the comparator can help to design a variety of analog circuits. Almost all integrated analog-to-digital converters contain comparator modules inside, which are used to quantize analog signals, or to judge signal states and other applications. [0003] Due to the high sensitivity of traditional comparators, they are easily affected by input mismatch errors and noise, resulting in output voltage jumps....

AI Technical Summary

Problems solved by technology

Increasing the input resistance will cause the resistance of the voltage divider to increase

Third, the equivalent input noise and mismatch voltage of the comparator are large

Because the effective input signal is also attenuated by the divider resistor

Fourth, the cost is higher

Fifth, the hysteresis window of the traditional hysteresis comparator is determined by the input resistors R1, R2 and the power supply voltage, which requires high precision of the resistors. At the same time, the size of the hysteresis window is limited by the power supply voltage

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