Multi-lamp Controller for CCFL Displays
Microsemi announced a high performance multi-lamp controller designed with features optimized for lighting the cold cathode fluorescent lamps used in large screen LCD TV applications. The LX6501 controller minimizes external components by fully integrating on-chip gate drivers having the capacity to drive N channel power MOSFETs on both the low and high sides of full bridge inverters. Input voltages can be as high as 27V. An on-chip regulator generates internal driver operating voltages that supply the output gate drive circuit. Additional features include the capability to synchronize both the frequency and phase of the lamp current between inverters or to an external synchronization signal; enhanced lamp current regulation accuracy and dynamic response at transient conditions; comprehensive dimming control of display brightness; extensive fault detection including open lamp, over-voltage, short circuit, over-current and over-temperature protection; and a programmable input under voltage lock out (UVLO) protection circuit to monitor on-chip voltages and shut down the controller if needed. In addition to LCD TVs, the LX6501 high performance multi-lamp controller is appropriate for multi-lamp LCD monitors and supports EEFL and FFL lamps, as well as CCFL backlight systems.