Description

     The AT405U monolithically integrates a transistor, diodes and resistors to function as a Constant Current Regulator (CCR) for LED driving. The device regulates with a preset 50mA nominal that can be adjusted with external resistor up to 100mA. It is designed for driving LEDs in strings and will reduce current at increasing temperatures to self-protect. Operating as a series linear CCR for LED string current control then it can be used in applications with supply voltages up to 40V.

With no need for additional external components, this CCR is fully integrated into a SOT26 (SC74R) minimizing PCB area and component count.

Feature

    ED Constant Current Regulator Using PNP Emitter-Follower with Emitter Resistor to Current Limit

    I_OUT = 50mA ± 10% Constant Current (Preset)

    I_OUT Up to 100mA Adjustable with an External Resistor

    V_S – 40V Supply Voltage

    P_D up to 1W in SOT26 (SC74R)

    LED Dimming Using PWM up to 25kHz

    Negative Temperature Coefficient (NTC) Reduces IOUT with Increasing Temperature

    Parallel Devices to Increase Regulated Current

    Totally Lead-Free & Fully RoHS Compliant (Notes 1 )

    Halogen and Antimony Free. “Green” Device (Note 2)

Applications

    Constant current regulation (CCR) in:

    Emergency Lighting

    Signage, Advertising, Decorative and Architectural Lighting

    Retail Lighting in Fridge, Freezer Case and Vending Machines

Mechanical Data

    Case: SOT26 (SC74R)

    Case Material: Molded Plastic. “Green” Molding Compound. UL Flammability Rating 94V-0

    Moisture Sensitivity: Level 1 per J-STD-020

    Terminals: Finish - Matte Tin Plated Leads. Solderable per MIL-STD-202, Method 208

    Weight: 0.018 grams (Approximate)

Application Information