
Semtech Corporation
Description
The SC4538 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.
FEATUREs
■ Input voltage range — 2.8V to 5.5V
■ 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 — 2mm x 2mm x 0.6mm
■ Lead-free package, WEEE and RoHS compliant
APPLICATIONs
■ DSLR, DSC, and Video Cameras
■ Cellular handsets
■ Portable media players
■ Personal navigation systems
■ Satellite radio
■ Handheld video games