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LM3501 Datasheet Synchronous Step-up DC/DC Converter

Manufacturer: National Semiconductor (now Texas Instruments)

General Description

The LM3501 is a fixed-frequency step-up DC/DC converter that is ideal for driving white LEDs for display backlighting and other lighting functions.

With fully intergrated synchronous switching (no external schottky diode required) and a low feedback voltage (515 mV), power efficiency of the LM3501 circuit has been optimized for lighting applications in wireless phones and other portable products (single cell Li-Ion or 3-cell NiMH battery supplies).

The LM3501 operates with a fixed 1 MHz switching frequency.

Overview

May 2005 www.DataSheet4U.com Synchronous Step-up DC/DC Converter for White LED Applications LM3501 Synchronous Step-up DC/DC Converter for White LED.

Key Features

  • n Synchronous rectification, high efficiency and no external schottky diode required n Uses small surface mount components n Can drive 2-5 white LEDs in series (may function with more low VF LEDs) n 2.7V to 7V input range n True shutdown isolation, no LED leakage current n DC voltage LED current control n Input undervoltage lockout n Internal output over-voltage protection (OVP) circuitry, with no external zener diode required LM3501-16: 15.5V OVP; LM3501-21: 20.5V OVP. n Requires only a small 1.