The SC4509 is a highly integrated step-up DC/DC converter targeted for white LED backlighting applications. It is designed to drive up to five LEDs with a wide input voltage range of 2.7 to 10 volts. Designed for 20V output voltage, the SC4509 operates with a constant 1.2MHz PWM frequency. To optimize efficiency, the feedback voltage is set to only 199mV, minimizing the power loss in the current setting resistor. The product requires only four external components (CIN, COUT, L and RSET), making it ideal for applications that require low cost and minimal PCB area.