A6274, A6274-1, A6284, A6284-1: Linear Current Regulator and Controller for Automotive LED Arrays

The A6274 and A6284 are programmable linear current regulator ICs for driving automotive LED arrays. The LED current is programmed by external resistors. These devices sink up to 60 mA (A6274) or 120 mA (A6284), from each of six LED pins, to drive strings of high-brightness LEDs. LED pins can be paralleled to drive even higher current LED strings. Current settings are typically accurate to 2%, while typical matching between LED strings is 0.8%.

LED light output can be adjusted by PWM dimming. The ICs provide an internal PWM dimming circuit that is programmed by external resistors for PWM frequency and duty cycle. It can also accept an external PWM signal. Multiple ICs can be configured in parallel for larger lighting systems. An internal FULL (VDR > 3.6 V) option is provided to override the PWMdimming ratio for full LED current.

LED current derating with temperature and programmable VIN levels allows operation over a wide range of operating conditions.

A GATE pin is provided to drive an external P-channel MOSFET, which serves as an active ballast resistor to reduce the heat dissipation within the IC package. It also serves as an input disconnect switch in the event of an LED string short-to-ground fault.

The A6274 and A6284 provide a non-latching option while the A6274-1 and A6284-1 provide a latching option.

APPLICATIONS

• Automotive rear combination light
• DRL/position
• General automotive lighting