Negative Voltage Comparator Circuit

Abstract

The invention relates to a negative voltage comparator circuit, comprising a comparator, a current mirror, an input signal circuit and a reference signal circuit; the current mirror provides equal bias currents for the input signal circuit and the reference signal circuit; the input signal circuit is connected to the negative input end of the comparator, and the reference signal circuit is connected with the positive input end of the comparator. The negative voltage comparator circuit has the advantages that high-precision negative voltage comparison is achieved with no negative references or negative voltage sources; as the internal structure of the comparator is not changed, the gain of the comparator itself may not be affected and uncontrollable offset voltage may not be caused; the cost and performance are comprehensively considered, the need for comparing various negative voltages can be met, and the circuit is easy to implement in engineering term and has low cost.

Description

technical field [0001] The invention relates to the field of circuit parameter measurement, in particular to a negative voltage comparator circuit. Background technique [0002] Comparators are commonly used in circuit control systems, and general comparators can only compare positive voltages. If you need to compare negative voltages, there are generally three methods: [0003] 1. Negative signals need to be converted into positive signals, and then compared with traditional comparators; [0004] 2. Use a fully differential comparator to directly compare negative voltages; [0005] 3. Artificially add an offset to the traditional comparator, so that the flip point of the comparator changes in the negative direction. [0006] Among them, both the first and second methods require a negative power supply and a reference source with a negative voltage in the circuit. However, due to cost considerations, most circuits do not provide a negative power supply and a negative refe...

AI Technical Summary

Problems solved by technology

[0006] Among them, both the first and second methods require a negative power supply and a reference source with a negative voltage in the circuit, but in most circuits, due to cost considerations, no negative power supply and negative reference source are provided.

Although the third method does not use the negative power supply and negative reference, this method changes the inherent comparator structure and artificially adds the offset of the comparator, which cannot be accurately implemented in the actual integrated circuit. Manufactured, the expected accuracy can only be achieved through later adjustments, and there is uncertainty in the later adjustments, which makes the workload of adjustments huge, which is not conducive to enterprise production

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