The A8508 is a multi-output white LED driver for backlighting LCD panels. It integrates a current-mode boost controller and eight individual current sinks.
The boost controller architecture allows for significant scaling of boost voltage to optimize the solution for the required number of LEDs per string. The FSET/SYNC pin either sets the required boost switching frequency or synchronizes the value in the range of 300 to 800 kHz.
The LED sink current value is set by an external ISET resistor (see figure 1). The eight LED sinks can also be combined to achieve even higher current per LED string.
The A8508 provides protection against output shorts and overvoltage, open or shorted LED pins, and overtemperature. A dual-level, pulse-by-pulse current limit function provides soft start and protects the external current switch against high current overloads. As an option, the A8508 can drive an external P-FET interfaced to the FAULT pin to disconnect the input supply from the system in the event of short-to-ground in the boost converter.
The A8508 is available in a 24-pin TSSOP package (suffix LP) with an exposed thermal pad for enhanced thermal dissipation. Contact factory for additional options, including: a 24-pin SOICW (LW) or a a 5 × 5 mm 28-contact QFN (ET) with exposed thermal pad. All packages are lead (Pb) free, with 100% matte tin leadframe plating.
This device is in production, however, it has been deemed Pre-End of Life. The product is approaching end of life. Within a minimum of 6 months, the device will enter its final, Last Time Buy, order phase. Date of status change: December 5, 2018.
Recommended Substitutions: ALT80600.
