AAT2401

DATA SHEET AAT2400/2401 Sixteen-Channel White LED Driver Solution with Full LED Current and Timing Control General Description 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 24V DC power supply. The master device supplies a 40V rail to drive 10 series LEDs with a typical VF of 3.6V. 16 precision current sinks split evenly between the master and slave devices provide constant current drive for up to 160 white LEDs. A SPI compatible interface operates up to 30MHz, allowing fast, independent digital control of each current sink. Full scale LED current is programmed from 30mA to 100mA using an external resistor. LED brightness variation is compensated by setting relative current sink magnitudes with an 8-Bit Dot Correction register for each LED current sink. The AAT2400/2401 provides a 12-bit programmable phase delay per LED current sink that can be used to synchronize the LEDs to VSYNC. Device addressing provides for up to 256 LED strings. A 12-bit programmable Gray Scale PWM brightness setting is generated via a clock from a PLL synchronized to VSYNC, or from the external GSCLK pin. The AAT2400/2401 provides fault handling and fault reporting through the interface. If LEDs are shorted on one or more strings, the current sinks will m...