LX1691B Enhanced Multi-Mode CCFL Controller ® TM P RELIMINARY D ATA S HEET KEY FEATURES Wide Input Voltage Capable Simultaneous Amplitude And Duty Cycle Dimming Modes Resistor programmable min and max lamp currents Digital Dimming Can Synch To External Or Internal Clocks 120 ms Power On Delay Open Or Shorted Lamp Regulation & Shutdown “On Chip” Full Wave Lamp Current Rectifier 16 Pin TSSOP Package Very Stable Oscillator with OnChip timing capacitor Enhanced Digital Dimming Resolution WWW . Microsemi .C OM 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 component failures. Competitive 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. BENEFITS Low Component Count / Module Cost / And Size High “Nits/Watt” Efficiency Can Operate Directly From a Single Li-Ion Cell Industries Safest And Highest Performing Strike Voltage Generation (Patented) Tight Operating Frequency Tolerance For Easier System Level RFI Control IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com Protected by U.S. Patents: 5,615,093; 5,923,129; 5,930,121; 6,198,234; Patents Pending PRODUCT HIGHLIGHT Traditional Analog Lamp Current (mA) _ T2 VDC T1 Internal Digital Lamp Current (mA) + BRITE_IN T DD_CLK T _ T = 512 / DD_CLK Frequency Direct PWM (Analog) T Lamp Current (mA) + BRITE_IN 2 +3V DD_CLK T = 256 / Lamp Frequency + VDC VDC 2 Lamp Current (mA) BRITE_IN VDC 0 DD_CLK T2 External Digital 2 +3V 0 T1 0 + BRITE_IN 2 _ 0 T1 T2 DD_CLK T T1 _ T2 LX1691B Four of Six Dimming Modes PACKAGE ORDER INFO TA (°C) MIN VDDP MAX VDDP -40 to +85 2.8V 5.5V PW Plastic TSSOP 16-PIN RoHS compliatn / Pb-free LX1691BIPW Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. LX1691BIPW-TR) 1 If the lamp frequency is less than 115Khz. Copyright © 2005 Rev. 0.4a, 1/26/2005 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 2 TM ® For a complete copy of this data sheet please contact your Microsemi sales representative @ http://www.microsemi.com/contact/contactfind.asp or contact us directly at [email protected]. Please include your contact information or vcard in your email. Copyright Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 WWW . Microsemi .C OM INFORMATION