LM3405XMKX

Overview

The LM3405XMKX is a constant current buck LED driver IC from Texas Instruments, designed for high-efficiency driving of high-power LEDs. It features an integrated 1A switch and supports PWM dimming. The device operates with an input voltage range of 3V to 22V and delivers up to 1A output current. It utilizes a TSOT-23-6 package and functions within a junction temperature range of -40°C to 125°C. The internal switching frequency is fixed at 1.6MHz.

Feature Summary

• Integrates a 1A power switch for simplified design
• Supports PWM dimming control for brightness adjustment
• Includes thermal shutdown protection for reliability

Applications

• High-brightness LED lighting systems
• General illumination applications
• Portable lighting devices

Procurement Notes

Verify the specific suffix (e.g., NOPB) for RoHS compliance status, as standard versions may not meet environmental regulations. Confirm package availability and lead times through authorized distributors, noting that some variants may be discontinued or have limited stock. Ensure the ordering part number matches the required pin configuration and thermal performance specifications.

Selection Notes

Select this component for applications requiring a compact, high-efficiency solution for driving single-channel high-power LEDs. Consider the fixed 1.6MHz frequency when designing external inductors and capacitors. Evaluate the thermal requirements based on the TSOT-23-6 package size and expected ambient temperatures. Verify compatibility with the system's input voltage range and dimming control signals.

Part Context

The LM3405 series represents Texas Instruments' entry-level constant current buck regulators for LED applications. The XMKX variant specifically denotes the TSOT-23-6 thin package option, offering a smaller footprint compared to larger packages like MSOP. This family is targeted at cost-sensitive and space-constrained lighting designs where efficiency and simplicity are prioritized.

Replacement Considerations

Direct substitutes include LM3405XMK/NOPB and LM3405AXMK/NOPB. Verify pinout compatibility and electrical parameters before substitution. Note that the 'A' suffix may indicate updated revisions or minor parameter variations. Check for RoHS compliance differences between original and replacement parts.