Semtech Corp. announces its model SC4509 step-up converter for white LED backlight applications with an integrated Schottky diode in a 2 mm × 2 mm × 0.8 mm package. This converter can drive up to five white LEDs in series to provide a tiny system for small LCD displays. Its built-in Schottky diode saves board space while providing efficiencies of over 80 percent. To simplify control of the backlight, the device features a combination enable and PWM dimming pin that allows the user to turn the device ON and OFF, or to apply a PWM dimming signal of up to 10 kHz to control the output current level and dim the LEDs. It features protection capabilities that include over-voltage protection, current limit, thermal shutdown and open LED protection.
Semtech Corp.