LM3500TL-16

Overview

The LM3500TL-16 is a synchronous step-up DC/DC converter designed for white LED applications. It features an integrated high-side N-channel power switch and supports input voltages from 2.7V to 5.5V. The device provides a maximum output voltage of 16V, typically suited for driving three or four white LEDs in series. It operates with a fixed switching frequency and includes programmable current regulation via an external resistor.

Feature Summary

• Integrated synchronous rectification using an internal N-channel MOSFET for improved efficiency
• Fixed-frequency operation simplifies external component selection and filtering requirements
• Programmable constant current output allows precise control of LED brightness

Applications

• Driving multiple white LEDs in series for portable displays
• Backlighting systems for mobile phones and handheld devices
• General-purpose LED lighting in battery-powered equipment

Procurement Notes

Verify the specific suffix 'TL-16' to confirm the 16V output limit and package type. Ensure compatibility with the intended PCB footprint, as the component utilizes a micro SMD package. Cross-reference the manufacturer designation, noting that National Semiconductor products are now managed under Texas Instruments. Confirm the presence of the NOPB lead-free designation if required by environmental standards.

Selection Notes

Select this component when a compact solution is needed for driving series-connected white LEDs from a single-cell lithium battery or similar low-voltage source. The fixed switching frequency reduces design complexity compared to adjustable frequency converters. Consider the thermal performance of the micro SMD package relative to the expected continuous current load and ambient operating conditions.

Part Context

This part belongs to the LM3500 family of synchronous boost converters. Variants within the family differ primarily in their maximum output voltage ratings and switching frequencies. The LM3500 series is distinct from the LM3501, which offers different electrical characteristics and pin configurations. This specific model targets applications requiring up to 16V output capability.

Replacement Considerations

The LM3500TLX-16/NOPB is a direct equivalent variant differing only in tape-and-reel packaging. Other LM3500 variants may require verification of output voltage limits and pin compatibility before substitution.