The XC9404 series are LED lighting offline controllers that use PFM(Pulse Frequency Modulation) control and have a Power Factor improvement function. The operating input voltage range is 85VAC to 270VAC, and the current is controlled on the primary side without using a Opto-coupler or secondary side control circuit. Because LED current fluctuations caused by input voltage fluctuations and LED voltage fluctuations can be suppressed, a stable LED lighting power supply is obtained.