High-threshold value voltage comparison circuit consisting of high-precision low-voltage comparator

Abstract

The invention aims to provide a circuit for realizing high-threshold value comparison by using a high-precision low-voltage comparator. The circuit mainly comprises low-voltage operational amplifiers omp1 and omp2, resistors R1, R2 and R3, M2, M3, M1 and M4, wherein the M2 and the M3 are power metal-oxide semiconductors (PMOS) with the breadth length ratio of 1:1 and form a current mirror; the M1 and the M4 are two high-voltage field effect transistors; and the omp2 is used as a comparator. Compared with the circuit manufactured by the conventional method, the circuit has the advantages of simpleness, low power consumption, great reduction in cost and use range extension by using a low-voltage device to realize the high-threshold value comparison. A high threshold value is parallelly shifted to a low-threshold value range to serve as an input of the low-voltage comparator, so that the high-threshold value comparison can be realized. The integrated production of the circuit can be realized by monolithic integration process technology (a BCD process).

Description

technical field [0001] The invention relates to basic electronic circuit technology, in particular to a circuit for realizing high-threshold voltage comparison with a high-precision low-voltage comparator. Background technique [0002] The voltage comparator is referred to as a comparator for short. Its basic function is to compare two input voltages, and output a high-level or low-level voltage according to the comparison result, and judge the magnitude and polarity of the input signal accordingly. Voltage comparators are often used in many occasions such as automatic control, waveform generation and conversion, analog-to-digital conversion, and limit alarms. Comparators are one of the most widely used circuits in electronic systems. [0003] At present, in the electronic circuit industry, comparator circuits composed of low-voltage devices have relatively high precision, but their comparison voltage range will be limited by the device voltage, which is generally relatively...

AI Technical Summary

Problems solved by technology

Some comparators are disclosed in some Chinese patents such as 200810055879.4 and 200710188495.5, but they fail to solve the problem of comparing two voltages with a large difference between the two voltages

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