Constant Current Driving Circuit And LED Backlight Apparatus Using The Same

摘要

SUMMARY OF THE INVENTION The present invention solves the problems of the prior art described above, and provides a circuit capable of constant current control with only the converter section, without the need to ground the detection section on the output side. A constant current drive circuit according to the present invention includes a control IC for generating a switching signal, an input terminal for receiving an input power source, a switching element for receiving the switching signal, and switching the input power source based on the switching signal; And a rectifier diode, a smoothing inductor, and a smoothing capacitor for rectifying, smoothing, and outputting the output current switched by the switching element. The control IC generates a reference signal generating a reference signal having information on a target constant current, receives the current of the input power supply and the reference signal, compares the current of the input power supply with the target constant current, and outputs a reset signal. A comparator configured to receive an external clock as a set signal, output a flip-flop signal having time information for receiving the reset signal and maintaining the set state, and receiving the flip-flop signal and receiving the flip-flop signal. And a delay unit configured to control the switching device by outputting the switching signal to the switching device.