The AP3019A is an inductor-based DC/DC converter designed to drive up to eight white °Cs in series for backlight. Only one feedback resistor is needed to control the °C current and obtain required brightness. A constant frequency 1.2MHz PWM control scheme is employed in this IC, which means tiny external components can be used. Specifically, 1mm tall inductor and 0.22μF output capacitor for a typical application is sufficient. Additionally, the Schottky diode in boost circuit is integrated on this chip. AP3019A also provides a disable pin to ease its use for different systems. The output over-voltage protection is implemented in AP3019A. When any °C is broken or in other abnormal conditions, the output voltage will be clamped.