Fluorescent Lamp DRVR 20V 18-Pin SOIC

The UC1871 Family of IC’s is optimized for highly efficient fluorescent lamp control. An additional PWM controller is integrated on the IC for applications requiring an additional supply, as in LCD displays. When disabled the IC draws only 1µA, providing a true disconnect feature, which is optimum for battery powered systems. The switching frequency of all outputs are synchronized to the resonant frequency of the external passive network, which provides Zero Voltage Switching on the Push-Pull drivers. Soft-Start and open lamp detect circuitry have been incorporated to minimize component stress. An open lamp is detected on the completion of a soft-start cycle. The Buck controller is optimized for smooth duty cycle control to 100%, while the flyback control ensures a maximum duty cycle of 95%. Other features include a precision 1% reference, under voltage lockout, flyback current limit, and accurate minimum and maximum frequency control.

1µA ICC when Disabled

PWM Control for LCD Supply

Zero Voltage Switched (ZVS) on Push-Pull Drivers

Open Lamp Detect Circuitry

4.5V to 20V Operation

Non-saturating Transformer Topology

Smooth 100% Duty Cycle on Buck PWM and 0% to 95% on Flyback PWM