Apparatus for driving interleaved fly-back type of led

An interleaved flyback LED drive unit is provided to reduce ripple change of output current by reducing ripple generated in current drive through the current drive of anti-phase with an interleaved fly-back method. A rectifier(20) rectifies AC power source to a first DC power source. The first DC power source comprises primary current. A PWM controller(100) supplies a first switching signal(SS1) and a second switching signal(SS2) having opposite phases according to the load of an LED array(LED-AY). A first transformer converts the primary current(I1a) from rectifier into the secondary current(I2a). The transformed secondary current is supplied to the LED array. The second trans converts the primary current(I1b) into the secondary current(I2b) from the rectifier. The transformed secondary current is supplied to the LED array. A first power switch performs off switching action according to the first switching signal. The primary current flowing into primary winding of the first transformer is turned on/off by on/off switching operation of the first power switch. A second power switch performs off switching action according to a second switching signal. The primary current flowing into the primary winding of the second transformer is turned on/off by on/off switching operation of the second power switch.