Load drive circuit with inrush current protection

Abstract

The invention discloses a load drive circuit capable of protecting surge current, which comprises a switching circuit, a conversion controller, a load drive adjuster and a surge current protective circuit, wherein the switching circuit is used for being coupled with an input power, and providing a driving power for driving a load at an output end; an output capacitor of the switching circuit is coupled with the output end; the conversion controller controls the size of the driving power provided by the switching circuit according to current or voltage of the load; the load drive adjuster is connected with the load in series at the output end of the switching circuit for regulating and controlling the electrical property state of the load; and the surge current protective circuit is coupled with a link point between the load drive adjuster and the load and the output capacitor so as to provide a one-way electric charge conduction path for the output capacitor.

Description

technical field [0001] The invention relates to a load drive circuit with surge current protection, especially a load drive circuit with capacitor as surge current protection. Background technique [0002] See figure 1 , is a schematic circuit diagram of a traditional light-emitting diode driving circuit. The LED driving circuit includes a conversion controller 100 , a boost conversion circuit 160 , an output capacitor C, an LED module 150 , a minimum voltage selection circuit 140 and a current balance circuit 145 . The boost conversion circuit 160 is a DC-to-DC boost conversion circuit, including an inductor L, a switch SW and a rectification component D, one end of the inductor L is coupled to an input power supply Vin, and the other end is coupled to one end of the switch SW; The other end of the changeover switch SW is grounded. The positive terminal of the rectifier component D is coupled to the connection point of the inductor L and the switching switch SW, and the ...

AI Technical Summary

Problems solved by technology

This may cause the actual breakdown voltage of the transient voltage suppressor to be close to the withstand voltage of the current balance circuit 145, so that when electrostatic discharge occurs, the current balance circuit 145 also temporarily exceeds the withstand voltage and affects the service life of the current balance circuit 145.

Therefore, in actual circuit applications, most of them still choose not to use electrostatic protection circuits, so that in actual use, the reliability of the product is low, and it cannot pass the relevant electrostatic test specifications.

Images