Description
The FL7734 is a highly integrated PWM controller with advanced Primary-Side-Regulation (PSR) technique to minimize components for low power LED lighting solutions. Using the innovative TRUECURRENT® technology for tight constant-current control, it enables designs with constant-current (CC) tolerance of less than ±1% in the wide line voltage range to meet stringent LED brightness requirements.
FL7734 can operate with all types of phase cut dimmers. Phase cut dimming is managed smoothly by Fairchild’s proprietary constant input current control and bleeding current control to achieve excellent dimmer compatibility without visible flicker.
The controller can automatically detect whether there is a dimmer connection. In non dimming mode, the operating mode is set to optimize power factor and THD by enabling linear frequency control and voltage mode based on DCM.
An external high-voltage bleeding circuit is utilized to implement fast startup and high system efficiency. The FL7734 also provides powerful protections, such as LED open / short, sensing resistor shorted, and over temperature for high system reliability. The FL7734 is available in 16-pin Small-Outline Package (SOP).

Features
■ Excellent Dimmer Compatibility by Active Dimming
   Control
■ Programmable Dimming Curve and Input Current
   Management
■ Constant LED Current Regulation in Large Phase
   Angle Range
■ Cost-Effective Solution without Input Bulk Capacitor
   and Feedback Circuitry
■ Accurate Constant-Current (CC) Control,
   Independent on Line Voltage, Output Voltage,
   Magnetizing Inductance Variation
■ Power Factor Correction (PFC)
■ Fast Startup utilizing Bleeding Circuit
■ Open-LED Protection
■ Short-LED Protection
■ Sensing Resistor Short Protection
■ Cycle-by-Cycle Current Limiting
■ Over-Temperature Protection with Auto Restart

Applications
■ LED Lighting System