Description

    This Linear LED driver is designed to meet the stringent requirements of automotive applications.

    The AT402U monolithically integrates a transistor,diodes and resistors to function as a Constant Current Regulator (CCR) for LED driving. The device regulates with a preset 20mA nominal that can be adjusted with an 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, 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.

Applications

    Constant current regulation (CCR) in automotive LED lighting:

     Interior and Exterior Automotive LED Lighting

    Dome and Mood Lighting

    Puddle Lighting

    Side Marker Lights

Features

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

     I_OUT = 20mA ± 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 I_OUT 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)

Application Information

Figure: 1 Typical Application Circuit for AT40X LED Driver