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