Low-power-consumption high-speed current comparator circuit

Abstract

The invention discloses a low-power-consumption high-speed current comparator circuit. Two NMOS (N-channel metal oxide semiconductor) tubes with different threshold voltages, namely a first low-threshold NMOS tube and a first NMOS tube, are used as input geminate transistors of a comparator; the input current flows into a source resistor of the first low-threshold NMOS; when the input current reaches a threshold value, the first NMOS tube NM1 is opened so as to pull down the drain electrode of the first NMOS tube NM1, a comparison signal VOUT1 generated by the comparator is turned over, and the threshold value of the input current is determined by the difference between the threshold voltages of the input geminate transistors and the trimming resistor. According to the invention, the voltage conversion of the input current, the generation of the reference level and the signal comparison are realized in one combined structure, so that the power consumption is saved, and the zero drift along with the temperature is realized. In addition, in order to further improve the speed, an auxiliary clamping module is further arranged, and the output voltage of the comparator is clamped at a voltage lower than that of the power supply by utilizing the clamping effect, so that the overturning speed of the comparator is increased.

Description

technical field [0001] The invention belongs to the technical field of analog circuit comparators, in particular to a source input current comparator circuit with low power consumption and high speed. Background technique [0002] In the field of analog power supply switching power supply, the current mode control circuit has the following advantages over the voltage mode control circuit: (1) high speed; (2) smaller chip area; (3) low power supply voltage and Power consumption; (4) Compatible with digital integrated circuit technology. As the basic unit of the current mode signal processing circuit, the current comparator plays an important role in the design of the integrated circuit. For the over-current protection design of the switching power supply, the over-current comparator is used as a part of the over-current protection circuit, and its performance directly affects the stability and reliability of the system. Since the rising slope and falling slope of the induct...

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Problems solved by technology

[0003] Traff H.Novel approach to high speed CMOS current comparators[J].Electronics Letters,1992, 28(3):310-312. A current comparator based on source-following stage is proposed. The advantage of this structure is the delay time Short and relatively high precision, but the structure has a dead zone when working with small signals within the dynamic range of the input voltage, which is a serious disadvantage

In order to improve this problem, Banks D.ToumazouC.Low-power high-speed current comparator design [J].Electronics Letters,2008,44(3):171-172. In the paper, it is proposed that the input stage adopts multi-stage cascading. Constitutes a current comparator, but this structure has a large drift with temperature and consumes a lot of power

There is also a current comparator usually composed of a differential structure, which is commonly used in a differential amplifier. The differential amplifier can suppress common-mode noise and improve the signal processing accuracy of the circuit, but this circuit increases the complexity of the circuit and increases the chip area and cost, usually the structure is suitable for parallel ADC

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