LX1691B Datasheet | Microsemi

DESCRIPTION The LX1691B is an enhanced Direct modes that control lamp current amplitude Drive CCFL (Cold Cathode Fluorescent and duty cycle simultaneously or separately. Lamp) Controller. Its architecture is based on Designers can select normal or reverse the LX1691. The LX1961B is optimized for polarity dimming and precisely program wide input voltage applications. It is similar minimum and maximum lamp currents with to the LX1691 except it has a guaranteed resistors. Fault protection includes open minimum lamp strike interval of one second1 lamp voltage regulation and shutdown for to meet notebook and monitor panel over voltage and over current conditions. manufacturer’s specifications. The “B” The LX1691B employs Microsemi’s proven version also adds feed forward input voltage and patented strike method that allows sensing to enhance transient response when significant efficiency gains while used in inverters that derive lamp power guaranteeing strong striking power at all from unregulated input supplies and operating temperatures. Our method batteries. sweeps strike frequency smoothly up to the The LX1691B can also be used with unloaded resonant frequency of the lamp fixed input supplies where it produces and high voltage transformer. This, coupled performance equal to the LX1691. with the LX1691B’s active high output LX1691B based inverter modules can be voltage regulation, produces just enough designed for virtually any CCFL appliance strike voltage without generating from digital cameras and PDA’s to big unpredictable high voltage spikes that cause screen monitors and driver viewable arcing and ponent failures. petitive automotive displays. devices that simply switch to a higher New versatile dimming circuitry can frequency for striking do not have this “real accept digital and analog control inputs and time” control over output voltage, and provides six different dimming require much more attention to transformer design. IMPORTANT: For the most current data,...