The LTM8040 is a complete step-down DC/DC switching converter system that can drive up to 1A through a string of LEDs. Its 4V to 36V input voltage range makes it suitable for a wide range of power sources, including 2-cell lithium-ion battery packs and rectified 12V AC power.
This document is Design Note 445 from Linear Technology Corporation, detailing the features and application of the LTM8040 uModule LED Driver. The device integrates all driver circuitry, including an inductor, into a single surface-mount package to simplify board layout for lighting designs.
The LTM8040 is a complete step-down DC/DC switching converter system capable of driving up to 1A through a string of LEDs with input voltages ranging from 4V to 36V. Key features include analog and PWM dimming capabilities, an open LED protection clamp, and low power shutdown states.
| Output Current | up to 1A |
|---|---|
| Input Voltage Range | 4V to 36V |
| Dimming Range | 250:1 |
| Output Voltage Clamp | 14V |
| Default Switching Frequency | 500kHz |
| Maximum Switching Frequency | 2MHz |
| Package Dimensions | 15mm x 9mm x 4.32mm |
| ADJ Pin Input Range | 0V to 1.25V |
The LTM8040 can drive up to 1A through a string of LEDs.
The device supports an input voltage range from 4V to 36V.
Current is adjusted via an ADJ pin accepting 0V to 1.25V or by applying a single resistor from ADJ to ground.