SC4540 Datasheet - Semtech Corporation

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