LX1691 Datasheet | Microsemi

DESCRIPTION KEY FEATURES . Microsemi . C OM Microsemi’s LX1691 is a cost reduced, enhanced feature set, Direct Drive CCFL (Cold Cathode Fluorescent Lamp) Controller. Its architecture is based on the very popular LX1689. By limiting VDDP to 5.5V and using advanced processing, die size and package pin count is decreased while improving dimming precision. LX1691 based inverter modules can be designed for virtually any CCFL appliance from digital cameras and PDA’s to big screen monitors and driver viewable automotive displays. New versatile dimming circuitry can accept digital and analog control inputs and provides six different dimming modes that control both lamp current amplitude and duty cycle, either simultaneously or separately. Designers can select normal or reverse polarity dimming and precisely program minimum and maximum lamp currents with resistors. The LX1691 fault shutdown feature is enhanced to include regulation and shutdown for over voltage and over current conditions. Microsemi’s proven and patented Direct Drive architecture works with system voltages from 3 volts to more than 50 volts, limited only by the external power FET’s that drive the high voltage transformer. The LX1691 includes the Microsemi proven and patented strike method that allows significant efficiency gains while guaranteeing strong striking power at all operating temperatures. Our method sweeps strike frequency smoothly up to the unloaded resonant frequency of the lamp and high voltage transformer. This, coupled with the LX1691’s active high output voltage regulation, produces just enough strike voltage without generating unpredictable high voltage spikes that cause arcing and ponent failures. petitive devices that simply switch to a higher frequency for striking do not have this “real time” control over output voltage, and require much more attention to transformer design. - Simultaneous Amplitude And Duty Cycle Dimming Modes - Resistor Programmable Min and Max Lamp Currents -...