The LM3500TL-21 is a high-efficiency, fixed-frequency step-up DC-DC converter with a built-in Schottky diode. Designed by National Semiconductor (now Texas Instruments), this converter efficiently boosts input voltages ranging from 2.7V to 5.5V to a fixed output voltage, optimized for driving white LEDs. Its high efficiency and small solution size make it ideal for portable applications requiring extended battery life and compact designs.

Applications

• White LED backlighting for LCD displays
• Mobile phones
• PDAs
• Digital cameras
• Portable media players

Features

• Input Voltage Range: 2.7V to 5.5V
• Fixed Output Voltage (optimized for white LEDs)
• High Efficiency (up to 85%)
• Built-in Schottky Diode
• Fixed Frequency Operation
• Small Solution Size
• Current Mode Control
• Overvoltage Protection

Benefits

• Extended Battery Life thanks to its high efficiency in converting the input voltage.
• Compact Design due to its small size and integrated components, ideal for portable devices.
• Simplified Design with minimal external components required due to the integrated Schottky diode.
• Stable and Reliable LED Lighting through its fixed output voltage and current mode control.
• Protection from Overvoltage Conditions protecting the LEDs and the converter itself.

Additional Details

The LM3500TL-21 utilizes a fixed-frequency, current-mode control architecture to provide stable and efficient operation. The integrated Schottky diode reduces the external component count and simplifies the board layout. The converter operates at a fixed switching frequency (typically around 1 MHz), allowing for the use of small external inductors and capacitors. The overvoltage protection feature prevents damage to the LEDs in case of an output overload. The datasheet provides detailed specifications, application circuit diagrams, and layout guidelines for optimal performance.