SC4540ULTRT

Overview

The SC4540ULTRT is a single-phase, single-chip IMVP-6/6 Vcore power supply manufactured by Semtech Corporation. It integrates an 800kHz current-mode PWM boost converter and a 30mA programmable low dropout current sink regulator designed for regulating current in series strings of white LEDs. The device supports an input voltage range of 4.5V to 12V, making it suitable for dual-cell Li-ion powered applications. Key electrical parameters include a switching frequency of 800kHz, a minimum over-voltage protection threshold of 38V, and a typical shutdown current of less than 0.1μA. It operates within a temperature range of -40°C to +85°C and utilizes an ultra-thin package measuring 2 x 2 x 0.6 mm.

Feature Summary

• Integrates an 800kHz current-mode PWM boost converter with a programmable low dropout current sink regulator for high efficiency.
• Features wide input voltage compatibility ideal for dual-cell lithium-ion battery systems.
• Includes built-in protections such as over-voltage protection at 38V minimum, under-voltage lockout, and thermal shutdown.
• Supports PWM dimming from 100Hz to 50kHz with soft-start capability to reduce in-rush current.

Applications

• DSLR cameras
• Digital still cameras (DSC)
• Video cameras
• Portable media players
• Set-top boxes

Procurement Notes

Verify the specific ordering suffix and package variant against the official Semtech datasheet to ensure compatibility with your design requirements. Confirm that the component meets all relevant RoHS and WEEE compliance standards required for your region. Cross-reference the manufacturer part number with authorized distributors to validate authenticity and traceability before finalizing procurement orders.

Selection Notes

Select this component when designing backlighting solutions for portable devices requiring small form factors and high efficiency. It is appropriate for applications powered by dual-cell lithium-ion batteries where a wide input voltage range is necessary. Consider the integrated Schottky diode and simple interconnect features if minimizing external component count is a priority for the PCB layout.

Part Context

The SC4540ULTRT belongs to the SC454 series of high-frequency LED drivers produced by Semtech. This series focuses on providing integrated solutions for LCD backlighting in consumer electronics. The device combines power conversion and regulation functions into a single chip, reducing the overall solution size compared to discrete implementations.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Consult Semtech technical support or authorized distributor catalogs for direct replacements or pin-compatible alternatives.