ADD5205

www.DataSheet.co.kr Four-String White LED Driver Data Sheet FEATURES White LED driver based on inductive boost converter Input voltage range: 2.8 V to 18 V Internal compensation 1 MHz fixed operating frequency 28 V fixed overvoltage protection Built-in soft start for boost converter Drives up to 4 LED current sources LED current adjustable up to 25 mA for each channel DC current level brightness control with PWM input LED open fault protection General Thermal shutdown Undervoltage lockout 12-lead, 3 mm × 3 mm × 0.75 mm LFCSP package ADD5205 FUNCTIONAL BLOCK DIAGRAM STEP-UP SWITCHING REGULATOR 4-CHANNEL CURRENT SOURCES BRIGHTNESS CONTROL LOGIC UNDERVOLTAGE LOCKOUT SOFT START THERMAL PROTECTION OVERVOLTAGE PROTECTION AUTODISABLE FOR LED OPEN Figure 1. APPLICATIONS Smart PCs, PMPs, tablet PCs, UMPCs, and notebooks GENERAL DESCRIPTION The ADD5205 is a white LED driver for backlight applications based on high efficiency, current mode, step-up converter technology. It is designed with a 0.3 Ω internal switch and 1 MHz fixed operating frequency. The ADD5205 contains four regulated constant current sources for uniform brightness intensity. Each current source is capable of driving up to 25 mA. The ADD5205 has four parallel strings of multiple series connected LEDs with ±2% current matching. The device provides adjustable current sources that drive up to 25 mA using an external resistor. The LED current can be controlled by a PWM signal input on the PWM pin. An internal circuit t...