GENERAL DESCRIPTION
An integrated boost (step-up) converter provides up to 45V output for driving series LEDs. Eight precision current sinks are programmed up to 45mA per string through one external RSET resistor, supporting up to 881 white LEDs at 360mA total output current. LED strings may be disabled or operated in parallel for increased drive capability. The boost output voltage is set by the LED string with the highest voltage requirement, allowing a wide range of LED characteristics. The PWM dimming range at 100Hz is up to 1,000:1. The boost switching frequency is selectable (up to 1.3MHz) to allow optimum efficiency and the smallest external L/C filtering components. Alternatively, the device may be synchronized to an external clock. Boost current mode control provides fast response to line and load transients. Integrated Light-Load mode ensures highest efficiency across the entire load range. Fault tolerant circuitry extends system life by disabling open LED strings. The unique high voltage current sinks prevent damage resulting from shorted LEDs.
Analogic Corporation
