The AAT2405 is a highly integrated, high efficiency 6-channel white LED backlight solution for large size LCD panels using edge lighting bars. The AAT2405 operates from a regulated 4.5V to 28V DC power source and is ideal for operation with common 12V to 24V AC-DC supplies used in LCD TV panels.

Each channel consists of a constant current sink that is user programmable up to a max of 150mA/channel with ±2.5% accuracy. Matching between channels is ±2.5% to provide uniform backlight brightness.

The AAT2405 uses external Power MOSFET transistors to stand-off the high voltage applied to the LED strings and to provide better heat dissipation. LED dimming is achieved by applying an external PWM signal. An internal clock and programmable phase delay function allow accurate PWM phase adjustment to each current sink or to selectable banks of current sinks. The AAT2405 has signal feed-through-function outputs for PWM dimming and forthe internal clock so cascade devices may be successively synchronized for both channel phase and timing. The AAT2405 constant current sinks may be set for phase delays individually or in banks of 2 or 3 LED strings.

The AAT2405 provides a current sense feedback input and output feed through function so the LED string voltage level can be fed back to an external high voltage boost converter. The function permits as many AAT2405s as needed to be cascaded from a single power source. An additional ICSFB output enables accurate feedback using generic DC/DC converters.

The AAT2405 provides an active low fault output. If an LED short or open circuit is detected or if an over-temperature condition arises, the fault is reported on the Fault pin. Thermal protection circuitry shuts down the current sinks in the event of an over-temperature condition.

The AAT2405 is available in a Pb-free 44 pin, 10x10mm E-LQFP package.