Line voltage compensation circuit based on peak detection current mode switch circuit

Abstract

The invention relates to a line voltage compensation circuit based on peak detection current mode switch circuit. The line voltage compensation circuit provided by the invention comprises a sample circuit and a compensation circuit, wherein, the sample circuit is used for sampling voltages related with the line voltage, thus obtaining sampling voltages which are in linear relation with the line voltage and scaling down in proportion. The compensation circuit is connected with the sample circuit and is used for compensating the non-inverting input end or inverted input end of a comparator in the peak detection circuit by utilizing the sampling voltage of the output by the sample circuit in an electrical signal mode, so that the inductance peak point current is equal to the inductance peak point current under the ideal situation. The line voltage compensation circuit provided by the invention not only has the advantages of steady loop and quick reaction speed and the like in the traditional peak detection current mode switch control circuit, but also can be used for overcoming the problem of unstable inductance peak point current caused by system delay, so that the inductance peak point current is invariant. The line voltage compensation circuit provided by the invention can be widely applied to analogue integrated circuits.

Description

technical field [0001] The invention relates to an analog integrated circuit, in particular to a peak detection current type switching circuit. Background technique [0002] The peak detection current switch control method is a commonly used method to control the peak current in the power system. The basic principle is to detect the inductor current value in real time through the comparator in the peak detection current switch circuit and then control the peak value of the inductor current to be constant. value. [0003] figure 1 It is the structural diagram of the traditional peak detection current-type switch control circuit. The loop structure of the peak detection current-type switch control circuit is simple, no loop compensation is needed, the entire loop is relatively stable, and the response speed is also fast. [0004] figure 1 Among them, the voltage value of several light-emitting diodes is VC. When the power tube MP is turned on, the power supply VIN charges ...

AI Technical Summary

Problems solved by technology

[0010] It can be known from formula (2) that the actual peak inductor current Ipk varies linearly with the input voltage VIN. Therefore, although the traditional peak-sensing current-mode switching circuit has certain advantages, due to the inherent delay of the traditional peak-sensing current-mode switching circuit system, The inductor peak current cannot become a constant value in the true sense, and the inductor peak current is higher than ideal and will vary with the supply voltage VIN

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