SC4538ULTRT

Overview

The SC4538ULTRT is a current-mode PWM boost converter and LED driver designed for LCD backlighting. It integrates an 800kHz boost converter with a programmable low-dropout current sink regulator capable of up to 30mA output. The device supports PWM dimming from 100Hz to 50kHz via the enable pin or analog control through the ISET circuit. It features over-voltage protection rated at a minimum of 38V, under-voltage lockout, and thermal shutdown. Operating within a 2.8V to 5.5V input range, it utilizes an MLPD-UT-6 package measuring 2mm x 2mm x 0.6mm.

Feature Summary

• Integrates an 800kHz current-mode PWM boost converter with a programmable low dropout current sink regulator
• Supports PWM dimming applied directly to the enable pin or controlled via analog signal on the ISET circuit
• Includes over-voltage detection, under-voltage lockout, and thermal shutdown for enhanced system protection

Applications

• LCD backlighting in DSLR cameras
• Digital still cameras (DSC)
• Video cameras
• Cellular handsets
• Portable media players

Procurement Notes

Verify the component against official Semtech datasheets to confirm the MLPD-UT-6 package type and electrical specifications. Ensure compatibility with the required input voltage range and LED string configuration. Check for RoHS compliance and lead-free status as specified in the manufacturer documentation. Validate that the specific suffix matches the intended tape-and-reel packaging requirements for your assembly process.

Selection Notes

Select this component when designing compact LCD backlight systems requiring high efficiency and small form factors. It is suitable for applications driving series strings of white LEDs where precise current regulation is necessary. Consider its 800kHz switching frequency for minimizing external passive component size. Evaluate the need for PWM dimming capabilities and ensure the input voltage aligns with the 2.8V to 5.5V operating range.

Part Context

The SC4538ULTRT belongs to Semtech's power management portfolio, specifically targeting portable electronics and imaging devices. It is part of a family of LED drivers optimized for space-constrained environments. The device addresses the demand for efficient backlighting solutions in mobile and consumer electronics by combining boost conversion and current regulation in a single ultra-thin package.

Replacement Considerations

Consult official Semtech documentation for verified substitute part numbers. Cross-reference electrical parameters such as input voltage range, maximum LED current, and package dimensions to ensure functional equivalence.