KB3417

Kingbor Technology Co.,Ltd TEL:(86)0755-26508846 FAX:(86)0755-26509052 KB4317 High Efficiency, Constant Current 2 Watt Boost White-LED Driver FEATURES Operating Voltage:2.3V~6.5V High Operating Frequency: 1.2MHz High Efficiency: Up to 90% High Output Voltage: Up to 32V High Output Power: 2W Shutdown Current <1PA 30V Output Over-voltage protection (min) Digital Dimming Control. Built-in Cycle-by Cycle Current-limiting. Built-in Soft-Start Function. 0.25V Low Reference Voltage(+/-5%) Tiny SOT23-6 Package DESCRIPTION The KB4317 step-up converter drives white LEDs with a constant current to provide backlight in cell phones, PDAs, and other hand-held devices. It features allowing series connection of the white LEDs so that the LED currents are identical for uniform brightness. An enable input can be pulsed repeatedly to adjust LED’s brightness. The fast 1.2 MHz current-mode PWM control allows for smaller capacitor and inductor. Fault condition protection uses cycle-by-cycle current limiting to sense maximum inductor current, thermal protection and over-voltage protection. Also included soft-start eliminates inrush current during start-up. The 0.25V low reference voltage minimized the power loss across the current-setting resistor. The KB4317 is available in SOT23-6 packages / www.DataSheet4U.com APPLICATIONS LED Module LED Backlight for LCD Display Vcc>3.6V(7 ”~8 ”) Constant Current Source! SIMPLIFIED BLOC DIAGRAM VIN LX ON/OFF Control Logic / PWM Dimming ...