Backlight driving circuit

Abstract

The invention discloses a backlight driving circuit, which comprises a transformer, a detection circuit and a judgment circuit, wherein the transformer is provided with a first output end, a second output end, a third output end and a fourth output end, and the output ends are sampled respectively to generate a first sampling signal, a second sampling signal, a third sampling signal and a fourth sampling signal; the detection circuit comprises a first detection node, a second detection node and a third detection node; and the judgment circuit is electrically connected to the detection circuit, when the output ends generate an abnormal state, the detection nodes generate at least one differential detection signal, and the judgment circuit executes a protective operation according to the atleast one differential detection signal to protect the backlight driving circuit. The backlight driving circuit has the advantages of simple circuit structure and low static power consumption. The backlight driving circuit adopts the detection circuit which is connected by adopting a loop mode; and when more than one output end synchronously generates abnormality, the detection nodes can generateat least one differential detection signal so that the backlight driving circuit can execute the protective operation.

Description

technical field [0001] The present invention relates to a backlight driving circuit, and in particular to a backlight driving circuit with a protection circuit. Background technique [0002] In recent years, as the size of liquid crystal display panels continues to increase, backlight driving circuits including multiple lamp tubes are more widely used to provide high-quality light sources required by liquid crystal display panels. [0003] see figure 1 . figure 1 It is a schematic diagram of a backlight driving circuit 1 in the prior art. Such as figure 1 As shown, the backlight driving circuit 1 includes a power module 10 and a transformer 12 , and the backlight driving circuit 1 is used to drive four groups of lamp tubes 14 . The transformer 12 is driven by the power module 10 to supply the electric energy required by the lamp tube 14 . Here, the one-for-four transformer 12 and four sets of lamp tubes 14 are taken as an example. In practical applications, the backligh...

AI Technical Summary

Problems solved by technology

At this time, the two sampling signals will change at the same time, so that the effect of differential detection cannot be exerted, and the detection node D1 (or detection node D2) remains at a low level (representing normal), resulting in misjudgment

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