Texas Instruments UC3871N

Description
The UC1871 family of ICs is designed for efficient fluorescent lamp control. It features an integrated PWM controller for additional power supply requirements, such as LCD displays. When disabled, the IC consumes only 1μA, providing a true disconnect function for battery-powered systems.
The switching frequency of all outputs is synchronized to the resonant frequency of an external passive network, enabling Zero Voltage Switching (ZVS) on the Push-Pull drivers. Soft-start and open lamp detection circuitry minimize component stress. Open lamp detection occurs at the end of a soft-start cycle.
The Buck controller provides smooth duty cycle control up to 100%, while the flyback controller ensures a maximum duty cycle of 95%. Other features include a precision 1% reference, undervoltage lockout, flyback current limit, and accurate minimum and maximum frequency control.

Features
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

Applications
Fluorescent lamp control
LCD display power supplies
Battery-powered systems