PWM Controller enhances single-stage fly-back converter performance

Providing features designed to enhance single-stage fly-back converter performance, Fairchild Semiconductor's FL6630 PWM controller is now available from Mouser stock. Proprietary TRUECURRENT topology enables the simplified circuit design for LED lighting applications. TRIAC dimming is smoothly managed by dimming brightness control without flicker. An LED lighting board can be implemented with few external components and minimized cost by using single-stage topology with primary-side regulation. It doesn't require an input bulk capacitor or feedback circuitry. To implement good power factor and low total harmonic distortion, constant on-time control is utilized with an external capacitor connected to the COMI pin, says the company. Precise constant-current control regulates accurate output current versus changes in input voltage and output voltage. The operating frequency is proportionally changed by the output voltage to guarantee Discontinuous Conduction Mode (DCM) operation with higher efficiency and simpler design. The FL6630 provides protections such as open-LED, short-LED, and over-temperature protections. Current-limit level is automatically reduced to minimize output current and protect external components in a short-LED condition. The FL6630 controller is available in an 8-pin Small Outline Package (SOP).