The AAT2400/2401 is a highly integrated, high efficiency white LED backlight solution for large size LCD panels used in LCD TVs. To accommodate power requirements, the solution consists of two devices, a master device (AAT2400) and a slave device (AAT2401). The devices operate from a regulated 12V or 24V DC power supply.

The master device supplies a 40V rail to drive 10 series LEDs with a typical V_F of 3.6V with up to 100mA. Sixteen precision current sinks split evenly between the master and slave devices provide a constant current drive for up to 160 white LEDs. Feedback from each of the current sinks is fed back to the boost converter to ensure the optimum voltage is applied to the LED strings. A high speed, SPI compatible interface allows fast, independent digital control of each current sink programmed to a maximum value using an external resistor.

An 8-Bit Dot Correction register compensates for variations in LED brightness during LCD setup, while two 12-Bit registers control the grayscale current and delay time. Channel ON/OFF control is also included. Each Master and Slave contains a 2-Bit register which allows up to 256 LED strings to be controlled in a single system. The Grayscale PWM clock is internally generated or can be externally supplied.

Fault handling and detailed reporting is handled by the SPI bus while a fault is indicated via a fault pin. The system monitors open or short circuit LEDs, and over-voltage, over-current and over-temperature protection.

The AAT2400 and AAT2401 are available in Pb-free, thermally enhanced 36-pin 5x5mm TQFN packages.