The AAT1599 is a step-up controller with 12-string constant current regulators designed for large size LCD panel backlight application.
The AAT1599 uses PWM current mode control. The switching frequency ranged from 150 to 500kHz can be set by external resistor. The input range of step-up converter is 5 to 28 volt. Precise 5 volt is supplied by internal LDO.
The AAT1599 can drive 12-strings of WLEDs using current balance. The mismatch between each string current is within 2.5%. LED current is adjustable up to 60mA. Its low 600mV regulation voltage on LED current source reduces power loss and improves efficiency.
PWM dimming is implemented with external PWM signal or DC input signal. The dimming PWM signal of DC input can be generated internally and the frequency is programmable by an external capacitor.