Description

The SC4540 is designed to regulate current for a series string of white LEDs in LCD backlighting applications where small size and high efficiency are priorities. This device integrates an 800kHz current-mode PWM boost converter and a 30mA programmable low dropout current sink regulator. The wide input voltage range of the SC4540 makes it ideal for use with dual-cell Li-ion powered applications.

Features

■ Input voltage range — 4.5V to 12V

■ Programmable LED current up to 30mA

■ Current-mode PWM control — 800kHz

■ Soft-start to reduce in-rush current

■ PWM dimming — 100Hz to 50kHz

■ PWM dimming at ISET — analog and filtered

■ Over-voltage protection — 38V (minimum)

■ Under-voltage lockout (UVLO)

■ Thermal shutdown

■ Shutdown current — <0.1μA (typical)

■ Ultra-thin package — 2 x 2 x 0.6 (mm)

■ Lead-free package, WEEE and RoHS compliant

Applications

■ DSLR, DSC, and Video Cameras

■ Portable media players

■ Set-top boxes

■ Personal navigation devices