UCC3974 Dual Cold Cathode Fluorescent Lamp Controller | TI.com

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Dual Cold Cathode Fluorescent Lamp Controller

Dual Cold Cathode Fluorescent Lamp Controller - UCC3974


Design goals for a cold cathode fluorescent lamp (CCFL) converter used for a liquid crystal display (LCD) monitor application include small size, high efficiency, and low cost. The UCC2974/UCC3974 CCFL controllers provide the necessary circuit blocks to implement a highly efficient LCD monitor backlight supply in a small 16-pin TSSOP package. The device features two control stages for operating independent resonant tanks for multi-lamp designs. The BiCMOS controller typically consumes less than 2-mA of operating current, improving overall system efficiency. External parts count is minimized and system cost is reduced by integrating such features as dual PWM driver stages, open lamp protection, overvoltage clamp, and synchronization circuitry between the buck and push-pull stages. The device operates in both analog and low-frequency dimming modes.


  • Synchronous or Nonsynchronous Operation
  • Dual Output and Control Stages
  • BiCMOS Technology
  • Accurate Current Control with 2-mA Typical Supply Current
  • Analog or Digital Low-Frequency Dimming Capability
  • Open Lamp Protection with Voltage Clamp
  • 4.5-V to 25-V Operation
  • PWM Frequencies Synchronized to External Resonant Tanks
  • TSSOP-16 (PW) Package
    • Portable PCs
    • Desktop LCD Monitors
    • Internet Appliances