microsemi integrated products 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 1 copyright ? 2003 rev. 1.2, 8/30/2006 www. microsemi . com lx1691 enhanced multi-mode ccfl controller p roduction d ata s heet tm ? description 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 v ddp 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 simul- taneously or separately. designers can select normal or reverse polarity dimming and precisely program mini- mum and maximum lamp currents with resistors. the lx1691 fault shutdown feature is enhanced to include regu- lation and shutdown for over voltage and over current conditions. microsemi?s proven and patented direct drive archit ecture 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 component failures. competitive 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. 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 key features ? simultaneous amplitude and duty cycle dimming modes ? resistor programmable min and max lamp currents ? digital dimming can synch to external or internal clocks ? 100 ms power on delay ? open or shorted lamp regulation & shutdown ? ?on chip? full wave lamp current & voltage rectifiers ? 16 pin tssop package ? very stable oscillator with on- chip timing capacitor ? soft start-up striking ? enhanced digital dimming resolution benefits ? low component count / module cost / and size ? high ?nits/watt? efficiency ? operates 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 product highlight 2 0 vdc t1 t2 brite_in dd_clk +3v traditional analog + t1 t2 _ 2 0 vdc brite_in dd_clk external digital t = 512 / dd_clk frequency + _ 2 0 vdc t1 t2 brite_in dd_clk direct pwm (analog) + t1 t2 _ 2 0 vdc brite_in dd_clk +3v internal digital t = 512 / lamp frequency + _ t lamp current (ma) lamp current (ma) lamp current (ma) lamp current (ma) t t t four of six dimming modes package order info pw plastic tssop 16-pin t a ( c) m in v ddp m ax v ddp rohs compliant / pb-free -40 to +85 2.8v 5.5v lx1691ipw note: available in tape & reel. append the lett ers ?tr? to the part number. (i.e. lx1691ipw-tr) l l x x 1 1 6 6 9 9 1 1
microsemi integrated products division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 tm ? www. microsemi . com copyright information thank you for your interest in microsemi ? ipg products. the full data sheet for this device contains proprietary information. to obtain a copy, please contact your loca l microsemi sales representative. the name of your local representative can be obtained at the following link http://www.microsemi.com/contact/contactfind.asp or contact us directly by sending an email to: ipgdatasheets@microsemi.com be sure to specify the data sheet you are requesting and include your company name and contact information and or vcard. we look forward to hearing from you.
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