LED Backlight Driver for LCD panels drives 36 LED strings

Allegro has released new multi-output WLED/RGB driver for LED backlighting of LCD monitors and TV display panels. This new device integrates a boost controller operating in constant frequency (programmable) current mode control, driving an external MOSFET. It integrates six internal current-sinks capable of up to 80 mA each, and they can be combined together to achieve even higher currents. PWM dimming allows LED currents to be precisely controlled as a percentage of the maximum setpoint determined by the user.

Furthermore, multiple A8512s can be connected in parallel, with one master controller controlling the boost stage, and up to five slave controllers, which act as LED sinks. This allows up to 36 LED strings to be powered by single boost converter to reduce the number of external components required.

The A8512 operates from a single supply of 8 to 24 V. It provides protection against overvoltage, open or shorted LED string, and overtemperature. A dual level cycle-by-cycle current limit function provides soft start and protects against overloads.

Package: 28-contact 5 mm × 5 mm QFN package (ET), with an exposed thermal pad for enhanced thermal dissipation. For single-sided PCB manufacturing capability, the device is also available in a 24-pin SOICW package (LB), with internally fused pins for enhanced thermal dissipation. Both packages are lead (Pb) free, with 100% matte tin leadframe plating.