LM3503ITL-44

LED Driver IC Overview

The LM3503ITL-44 is a dual-display constant current LED driver manufactured by Texas Instruments, formerly National Semiconductor. It operates as a step-up (boost) DC-DC regulator with an internal switch. The device supports a supply voltage range of 2.5V to 5.5V and delivers up to 750mA per channel at an output voltage of 44V. It features both analog and PWM dimming capabilities and operates at a switching frequency of 1MHz. The component is available in a 10-DSBGA package.

LED Driver IC Feature Summary

• Dual-output constant current regulation for independent backlight control
• Integrated high-voltage boost converter topology
• Supports mixed analog and pulse-width modulation dimming methods

LED Driver IC Applications

• Backlight drivers for mobile phone displays
• Power management for dual LCD panels in handheld devices
• Constant current regulation for high-brightness LED arrays

LED Driver IC Procurement Notes

Verify the manufacturer designation carefully, as the part was originally produced by National Semiconductor before its acquisition by Texas Instruments. Ensure the suffix /NOPB is included if lead-free compliance is required. Confirm the specific -44 output voltage variant matches the target display requirements rather than assuming generic family compatibility.

LED Driver IC Selection Notes

Select this component when driving two separate LED strings from a single low-voltage source. The 1MHz switching frequency allows for smaller external passive components compared to lower-frequency alternatives. Verify that the 44V output rating aligns with the series resistance of the connected LED loads to prevent overvoltage conditions during operation.

LED Driver IC Part Context

This IC belongs to the LM3503 family of power management integrated circuits designed specifically for portable electronics. It consolidates dual LED drivers into a single compact solution, reducing board space compared to discrete designs. The technology leverages advanced CMOS processes to achieve high efficiency in battery-powered applications.

LED Driver IC Replacement Considerations

The LM3503ITL-44/NOPB is the direct equivalent. Other variants within the family include the LM3503ITL-35 for different voltage outputs. Cross-referencing with TI documentation is recommended to ensure pinout and thermal characteristics remain identical.