Overvoltage protection circuit and load voltage regulation circuit

Abstract

The invention discloses an overvoltage protection circuit and a load voltage regulation circuit. The overvoltage protection circuit comprises a voltage division sampling circuit and a comparison circuit, wherein both ends of the voltage division sampling circuit are respectively connected with both ends of a load, and the sampling output end of the voltage division sampling circuit is used for outputting sampling voltage signals which are used for expressing voltage values at the two ends of the load; a first input end of the comparison circuit is used for receiving the sampling voltage signals, a second input end of the comparison circuit is used for receiving a reference signal, and the reference signal is high-end voltage or low-end voltage of the load; the sampling voltage signals are compared with the reference signal in the comparison circuit; when overvoltage occurs, the output end of the comparison circuit is used for converting high and low levels. The overvoltage protection circuit has the advantages that by using an operation amplifier as the comparison circuit, the load voltage can be regulated to maintain the constant voltage of the load; the overvoltage protection circuit is suitable for multiple topology structures, the compatibility is good, and the complicated peripheral circuit is not needed.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to an overvoltage protection circuit and a load voltage regulation circuit. Background technique [0002] LED driving circuits in the prior art can generally be applied to various LED driving topologies, such as Buck, Boost, Buck-Boost, and so on. Since an overvoltage protection circuit needs to be provided on the basis of the LED driving circuit, corresponding peripheral circuits need to be provided to cooperate with it. [0003] The overvoltage protection circuit in the prior art generally samples the output voltage of the LED driving circuit through a voltage divider circuit, and compares the sampled signal with the internal reference of the chip to determine whether it is overvoltage. However, since the reference inside the chip is fixed, in the application of different topologies, in the case of different loads, the judgment reference of overvoltage is actually diffe...

AI Technical Summary

Problems solved by technology

Due to the use of the overvoltage protection circuit of the prior art, there is not only the problem of poor compatibility, but also the complicated peripheral circuit will increase the power consumption and the cost of components

In addition, in the prior art, when the load does not share a common ground, since the internal reference of the chip is fixed, it is not conducive to the regulation of the constant voltage of the load.

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