LM3405 Datasheet | National Semiconductor

Description Integrated with a 1A power switch, the LM3405 is a current mode control switching buck regulator designed to provide a simple, high efficiency solution for driving LEDs. With a 0.2V reference voltage feedback control to minimize power dissipation, an external resistor sets the current as needed for driving various types of LEDs. Switching frequency is internally set to 550k Hz (LM3405-Y) or 1.6MHz (LM3405-X), allowing small surface mount inductors and capacitors to be used. The LM3405 utilizes current mode control and internal pensation offering ease of use and predictable, high performance regulation over a wide range of operating conditions. Additional features include user accessible enable/ dim pin for enabling and PWM dimming of LEDs, thermal shutdown, current limit and over voltage protection. Features n Thin SOT23-6 package n 4.0V to 20V input voltage range n 550k Hz (LM3405Y) and 1.6MHz (LM3405X) switching frequencies n 300mΩ NMOS switch n 30n A shutdown current n Enable/DIM input for enabling and PWM dimming of LEDs n Requires only low value, ceramic capacitors n Input voltage UVLO n Internally pensated current mode control n Thermal shutdown Applications n LED Driver n Constant Current Source Typical Application Circuit Connection Diagrams 6-Lead TSOT NS Package Number MK06A Pin 1 Indentification © 2006 National Semiconductor Corporation DS201789 .national. LM3405 500k Hz/1.6MHz 1A Constant Current Buck Regulator for Powering LEDs Physical Dimensions inches (millimeters) unless otherwise noted 6-Lead TSOT Package NS Package Number MK06A National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications. For the most current product information visit us at .national.. LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL PONENTS...