LED Drivers Designed for Backlighting Auto Infotainment Displays

Allegro MicroSystems Inc.'s A8502 and A8514 multi-output LED drivers for LCD backlighting integrate a current-mode boost converter with internal power switch and multiple current sinks. The LED sinks can be paralleled to achieve even higher LED currents. The devices are capable of operating from a single power supply from 5V to 40V, allowing the part to withstand a load dump condition encountered in automotive systems.

Both the A8502 and A8514 LED drivers can optionally drive an external PMOS to disconnect input supply from the system in the event of a fault. The devices, coupled with the external PMOS disconnect switch, provides protection against output short and overvoltage, open or shorted diode, open or shorted VLED pin, and over-temperature.

A dual level cycle-by-cycle current limit function provides soft start and protects the internal current switch against high current overloads. They have a high PWM switching frequency (>2MHz) that allows the devices to operate above the AM radio band. They also have a synchronization pin if the user wishes to be synch in the range of 600kHz to 2.25MHz.

The A8502KLPTR-T is offered in the 16-pin SSOP package and the A8514KLPTR-T is offered in the 20-pin SSOP package both with exposed thermal pad.

Allegro