Drive circuit for driving LED and LED string

Abstract

A light source driving circuit for driving a light emitting element comprises a power supply circuit, a light adjusting circuit, and a feedback circuit / control circuit, wherein the power supply circuit is coupled with one end of a light emitting element; the light adjusting circuit is coupled with the other end of the light emitting element; and the feedback circuit / control circuit is coupled between the power supply circuit and the light adjusting circuit. When the light source drive circuit turns off the power supply circuit to stop supplying power to the light emitting element, the feedbackcircuit / control circuit delays the time point for switching off the light adjusting circuit so as to prevent the light adjusting circuit from being broken down by over-high voltage.

Description

technical field [0001] The present invention relates to a driving circuit, and in particular to a driving circuit for driving light-emitting diodes and light-emitting diode strings. Background technique [0002] Light source driving circuits are widely used in various display devices, such as backlight driving circuits of liquid crystal displays, or light emitting diode (LED) driving circuits of handheld mobile devices. As display devices are increasingly used in various electronic products, the light source driving circuit has high development potential. There are many advantages that can be continuously improved and improved, including increased power conversion efficiency, improved stability, and so on. [0003] The structure of a known light source driving circuit for driving a light emitting diode string 101 is as follows: figure 1 As shown, the LED string 101 is composed of a plurality of LEDs 102 connected in series. This known light source driving circuit includes...

AI Technical Summary

Problems solved by technology

[0007] In this case, if the withstand voltage of the dimming circuit 107 is insufficient, the dimming circuit 107 will be broken down by the DC power voltage supplied by the DC-to-DC power converter 103, resulting in damage to the dimming circuit 107.

In addition, it may be necessary to use a dimming circuit 107 with a higher withstand voltage. However, the dimming circuit 107 with a higher withstand voltage will inevitably require a larger volume and a higher price. In addition to possibly increasing the volume of the overall circuit, It increases the cost of the circuit and thus reduces the competitiveness of the product in the market

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