Off-line controllers designed for LED lighting
The XC9401 series are off-line controllers for LED lighting. Operation within the range 85VAC - 270VAC and by DC input is possible by optimizing external components. Using selected components to match the circuit configuration, a wide variety of specifications can be realized.
Fixed off time control is used as the basic method, and with detecting the current that flows to the external power MOSFET, the current flowing to the LED is monitored and stable power for LED lighting is supplied. This series provides simple operation that can be applied to solution circuits with a variety of different specifications, from non-isolated circuit solutions using a coil to isolated circuit solutions using a transformer. Unlike an isolated circuit, a non-isolated circuit configuration does not require peripheral components such as a photo-coupler or snubber circuit, making it possible to reduce the component count and mounting area.
Two functional types are available, the XC9401A type and the XC9401B type, enabling selection to meet the characteristics required. The circuit configuration of the A type is designed to achieve a high power factor by synchronizing the LED current with the input voltage (sine wave). In this circuit configuration, a high capacity, high breakdown voltage electrolytic capacitor is not necessary after the bridge rectifying circuit from the AC input. An input filter removes high-frequency switching noise from the AC line, and therefore a low capacity ceramic capacitor can be used.
The B type holds constant the peak current that flows to the external power MOSFET due to switching, and is thereby able to maintain a constant LED current. By keeping the LED current constant, this circuit configuration makes it possible to achieve a stable light source with high efficiency.
The SOT-26 package enables reduction of the board mounting area for easy mounting on the light bulb. This series is an environment-friendly product that complies with the EU RoHS Directive and is Pb-free.