LED driver and LED lighting device

Abstract

An LED driver and an LED lighting device. The LED driver includes: a bridge circuit including first to fourth bridge arms, a first node between the first and second bridge arms, and a bridge between the second and third bridge arms. A second node, a third node between the third and fourth bridge arms, a fourth node between the fourth and first bridge arms, a DC voltage input between the fourth and second nodes, the first bridge arm includes a first Transistors, the second bridge arm includes a second transistor, the first and second transistors are controlled and turned on alternately; a parallel resonant circuit, coupled between the first and third nodes, includes a parallel resonant inductor and a resonant capacitor, parallel resonant The circuit is suitable for driving LED loads; the excitation source circuit is suitable for providing excitation current for the parallel resonant circuit; the starting circuit is suitable for controlling the conduction of the second transistor after the DC voltage is established, so that the parallel resonant circuit starts to vibrate. The LED driver of the invention has excellent load regulation rate and high driving efficiency.

Description

technical field [0001] The invention relates to the field of light source driver design, in particular to an LED driver and an LED lighting device. Background technique [0002] In the field of lighting, fluorescent lamp is a traditional light source. It is a low-pressure gas discharge lamp, which exhibits negative resistance characteristics during operation. Most of them need a matching electronic ballast during operation. The LED light source has shown a wide range of application prospects due to its advantages of high light efficiency, long life and low cost. In more and more application scenarios, people prefer to replace traditional fluorescent lamps with LED light sources. [0003] In the prior art, when replacing a fluorescent lamp with an LED light source, in order not to dismantle the electronic ballast, an LED light source compatible with the electronic ballast can be directly selected, so that only the old fluorescent lamp needs to be simply removed and replaced ...

AI Technical Summary

Problems solved by technology

The driving efficiency of this scheme is very high, and there is very little high-frequency oscillation in the resonant tank, but the load regulation of this scheme is very poor. For example, the LED driver designed is one-to-two (one power supply with two light bars) The driver, when driving an LED light source load including only one light bar, the load current will double, which may cause the LED light source load to be overheated and damaged

[0006] Therefore, in summary, the LED driver in the prior art has the technical problems of being unable to take into account low driving efficiency and poor load regulation.

Images