lin d oc #: 1611 description key features rangemax wide range dimming 8v to 18v input voltage range 30% smaller than cs-zvs models easy to use brightness control microamp sleep mode output short-circuit protection and automatic strike-voltage regulation 7.3mm max. module height, 16mm module width fixed frequency operation applications notebook and sub-notebook computers portable instrumentation desktop displays low ambient light conditions (i.e. aircraft cabins, automobile) benefits high efficiency and sleep mode feature extends computer battery life smooth, flicker free 1-100% full-range brightness control gives your product a high quality image output open circuit voltage regulation minimizes corona discharge for long life and high reliability power efficient, "low brightness" capability allows for advanced power management rangemax wide range dimming, single output inverter. the lxm1611 series of direct drive tm ccfl (cold cathode fluores- cent lamp) inverter modules are specifically designed for driving lcd backlight lamps. similar to the lxm1610, the lxm1611 ex- cels in applications where critical parameters include very wide range dimmability, high efficiency and reliable fail-safe design in a small form factor. unlike the lxm1610 or any traditional dimming ccfl inverters, the lxm1611 pro- vides the designer a vastly superior display brightness range. 100:1+ brightness range is achievable with virtually any lcd display. our wide range dimming provides excep- tional display readability at less than 1% of full brightness, allowing both power savings and low ambient light operating capability (i.e. "night readable"). the lxm1611 is recommended for use in panels with low-voltage insulation on the lamp return wire. rangemax digital dimming tech- nique. digital dimming provides flicker- free brightness control in any wide-range dimming application. dimming ratios greater than 100:1 can be achieved. incorporation of a video synchronization feature allows wide ratio dimming without the display dis- turbances and interference seen with com- petitive products. d igital d imming ccfl i nverter m odule p reliminary d ata s heet t he i nfinite p ower of i nnovation LXM1611-01 p atents p ending the modules are equipped with a dimming input that permits brightness control from an external potentiometer or dc voltage source. the resultant "burst drive" that energizes the lamp was designed specifically to ensure that no premature lamp degradation occurs. (see "how rangemax works" section) wide input voltage range. the mod- ules convert unregulated dc voltage from the system battery or ac adapter directly to high- frequency, high-voltage waves required to ignite and operate ccfl lamps. direct drive technology. the module design is based on a new direct drive topol- ogy, which provides a number of cost and performance advantages. the LXM1611-01 series direct drive inverters eliminate the clas- sic resonant inductor and capacitors, thus reducing cost and allowing a 30% reduction in module size. additional featur es. other benefits of this new topology are fixed-frequency op- eration and secondary-side strike-voltage regulation. strike-voltage regulation minimizes corona discharge in the output transformer and re- lated circuitry, providing longer life and higher reliability. all lxm1611 modules feature both open and shorted lamp protection. the lxm1611 is fully customizable (elec- tronically and mechanically) to specific cus- tomer requirements. copyright ? 1999 rev. 0. 5 7/02 1 11861 w estern a venue , g arden g rove , ca. 92841, 714-898-8121, f ax : 714-893-2570 l in f inity m icroelectronics i nc . product highlight r ange max vs . a nalog d imming rangemax tm rangemax technology allows the designer to operate in a lower "brightness" and therefore at lower "power consumption" than can be reached using traditional analog dimming inverters. dotted line indicates area where panel variations and parasitics will impact minimum light level with analog dimming. data presented for a rangemax inverter driving a 13.3" lcd with a 1.2 nit to 120 nit brightness range. the minimum power levels were 0.4 watts (rangemax) vs. 2.1 watts (analog dimming) for a power consumption savings of 1.7 watts. light output ( nits ) power used (watts) 2 0 30 45 60 75 90 105 5 4 3 1 standard analog dimming inverter linfinity's rangemax LXM1611-01 module order information note: for current data & package dimensions, visit our web site: http://www.linfinity.com.
d igital d imming ccfl i nverter m odule LXM1611-01 product databook 1996/1997 copyright ? 1999 rev. 0. 5 7 /02 2 p reliminary d ata s heet p atent p ending rangemax tm absolute maximum ratings (note 1) input supply voltage (v in ) .............................................................................................................................. .......................... -0.3v to 18v output voltage, no load ........................................................................................................ ...................... internally limited to 1800v rms output current ................................................................................................................. ............................ 10.0ma rms (internally limited) output power ................................................................................................................... ..................................................................... 6.0w input signal voltage (brite input) ............................................................................................. .......................................... -0.3v to 6.5v input signal voltage (sleep, v sync(-) , v sync(+) inputs) ............................................................................................................... -0.3v to v in ambient operating temperature .................................................................................................. ............................................ 0c to 70c storage temperature range ...................................................................................................... ............................................. -40c to 85c note 1. exceeding these ratings could cause damage to the device. all voltages are with respect to ground. currents are positiv e into, negative out of the specified terminal. recommended operating conditions (r.c.) this module has been designed to operate over a wide range of input and output conditions. however, best efficiency and perfor mance will be obtained if the module is operated under the condition listed in the ' r.c. ' column. min. and max. columns indicate values beyond which the inverter, although operational, will not function optimally. input supply voltage range (functional) v in input supply voltage (fully regulated lamp current) output power p o brightness control input voltage range v brt adj lamp operating voltage v lamp lamp current (full brightness) i olamp operating ambient temperature range t a parameter symbol units recommended operating conditions min. r.c. max. 81218v 91216v 45w 0.0 2.5 v 540 675 800 v rms 7.0 ma rms 070c electrical characteristics unless otherwise specified, these specifications apply over the recommended operating conditions and 25c ambient temperature f or the lxm1611. full bright lamp current i l (max) v brt adj = 2.5v dc , sleep = high, burst duty = 100%, v in = 9v dc minimum lamp current (note 2) i l (min) v brt adj = 0v dc , sleep = high, burst duty = 2%, v in = 9v dc lamp start voltage v ls 0c < t a < 40c, v in 7.0v dc operating frequency f o v brt adj = 2.5v dc , sleep = high, v in = 12v dc output pin characteristics parameter symbol test conditions units LXM1611-01 min. typ. max. 6.3 7.0 7.7 ma rms 0.14 ma rms 1500 1800 v rms 52 57 62 khz brite input input current i brt v brt adj = 0v dc input voltage for max. lamp current v c i o (lamp) = 100% duty cycle input voltage for min. lamp current v c i o (lamp) = minimum duty cycle -10 -12 -14 a dc 2.5 2.6 v dc 00v dc 2.2 v in v dc -0.3 0.8 v dc 120 180 a dc power characteristics sleep current i in (min) v in = 15v dc , sleep 0.8v 10 50 a dc run mode v sleep (hi) sleep mode v sleep (lo) input current i sleep sleep = 5.0v sleep input note 2. minimum lamp current required to maintain even light output may vary with display panel. 3. the module will be functional with pulse widths much larger than 250s, but will have limited dimming. v sync(-) / v sync(+) characteristics logic high level v synch (hi) logic low level v synch (lo) input impedance z in pulse width (note 3) t pw input frequency f sync 4.0 6.5 v dc -0.3 1.0 v dc 60 66 75 k ? 25 250 s 49 150 hz
d igital d imming ccfl i nverter m odule LXM1611-01 product databook 1996/1997 3 copyright ? 1999 rev. 0. 5 7 /02 p reliminary d ata s heet p atent p ending rangemax tm input power supply. (8v v in 18v) power supply return. on/off control. (2.2v < sleep < v in = on, -0.3v < sleep < 0.8v = off) brightness control (-0.3 to 2.5v dc ). 2.5v dc gives maximum lamp current. vertical syncronization input, negative going. vertical syncronization input, positive going. functional pin description conn. pin description cn1-1 v in cn1-2 cn1-3 gnd cn1-4 cn1-5 sleep cn1-6 brite cn1-7 v sync(-) cn1-8 v sync(+) cn1 cn2 cn2-1 v hi cn2-2 v lo high voltage connection to high side of lamp. connect to lamp terminal with shortest lead length. do not connect to ground. connection to low side of lamp. connect to lamp terminal with longer lead length. do not connect to ground. physical dimensions 3.93 (100) 2.06 (52.25) 0.64 (16) cn1 0.031 (0.79) max. 0.287 max. (7.3) warning!! high voltage present 0.15 (3.85) ? 0.116 (2.95) grounded mounting hole 2.36 (60) 1.20 (30.5) cn2 LXM1611-01 all dimensions are in inches (mm). connectors: recommended mate: cn-1 = molex 53261-0890 pins: 50079-8100*, housing: 51021-0800 * loose (-8000, chain) recommended #26 awg wiring cn-2 = jst sm02(8.0) b-bhs-tb pins: 5bh-001t-p0.5, housing: bhr-03vs-1 25s < t pw < 250s, 49hz < f sync < 150hz }
d igital d imming ccfl i nverter m odule LXM1611-01 product databook 1996/1997 copyright ? 1999 rev. 0. 5 7 / 0 2 4 p reliminary d ata s heet p atent p ending rangemax tm high voltage transformer i sense lamp v sense v brite transformer driver ramp gen. comparator v sync(-) v sync(+) ramp v hi v lo 0-2.5v dc how rangemax works lamp voltage & lamp current ? burst mode operation figure 1 ? 50% burst duty cycle figure 2 ? 2% burst duty cycle figure 3 ? 2% burst duty cycle (expanded time base) figure 4 ? rangemax block diagram rather than using the traditional dimming technique of varying lamp current magnitude to adjust light output, rangemax inverters use a fixed lamp current value with a duty cycle control method. the lamp current burst width can be modulated from 100% (continuous lamp current) down to a 2% duty cycle, allowing the lamp to be dimmed to less than 1% of its full brightness. as can be seen in trace 4 of figure 3 photo at right, careful design consideration was given to controlling lamp start voltage to softly start current flow. this eliminates current overshoot that can result in premature cathode wear and reduce lamp life. (770v rms ) (7.6ma rms ) (760v rms ) (6.7ma rms ) (760v rms ) (6.7ma rms )
d igital d imming ccfl i nverter m odule LXM1611-01 product databook 1996/1997 5 copyright ? 1999 rev. 0. 5 7 /02 p reliminary d ata s heet p atent p ending rangemax tm preliminary data - information contained in this document is pre-production data, and is proprietary to linfinity. it may not modified in any way without the express written consent of linfinity. product referred to herein is offered in sample form only, and linfinity reserves the right to change or discontinue this proposed product at any time. how rangemax works (continued) highlights on-board brightness control circuit includes a dc voltage to pulse width converter that minimizes system design work and system noise susceptibility. this provides a familiar and convenient interface while reducing the potential for externally induced noise which can cause lamp flicker. an on-board oscillator operates the inverter burst rate above 95hz, well beyond standard 50/60hz video refresh rates where the eye can perceive pulsing light. rangemax inverter modules are designed to operate with the burst frequency synchr onized to the video frame rate. this provides operation with no visible display disturbances caused by beat frequencies between the lamps and video frame rates. in applications with no access to a vertical sync, the in- verter burst frequency can be allowed to "free run" at 95hz. in this non-synchronous mode, minor display disturbances can be found under certain video conditions. this perfor- mance may be acceptable for many applications, but syn- chronization must be used when no disturbance can be tolerated. separate inputs are provided for negative and positive ver- tical sync pulses so external inversion is not needed. separate feedback loops for lamp current and open circuit voltage regulation insure reliable strike under all operat- ing conditions, automatic over-voltage prevention with bro- ken or failed lamps, and accurate lamp current regulation. rangemax and direct drive are trademarks of linfinity microelectronics inc. typical application the brightness control may be a simple 10k potentiometer or a voltage output dac. a pwm signal from a micro-controller may also be used with a suitable filter such as shown in figure 5a. if synchronization to the video framerate is desired, connect the vertical sync pulse from the system video controller to the appropriate v sync input. if the pulse is negative going ( ), connect it to v sync(-) . if positive going ( ), connect it to v sync(+) . if no video synchronization is desired, leave both v sync(-) and v sync(+) floating. if you need to turn the inverter on/off remotely, connect a 3v or 5v logic signal to the sleep input. if remote on/off is not needed, connect the sleep input to v in or any other voltage greater than 2.2v dc . connect v hi to high voltage wire from the lamp. connect v lo to the low voltage wire (wire with thinner insulation). never connect v lo to circuit ground as this will defeat lamp current regulation. if both lamp wires have heavy high voltage insulation, connect the longest wire to v lo . figure 5 ? potentiometer brightness control figure 5a ? pwm brightness control LXM1611-01 brite v hi v in sleep gnd ccfl tube 9-18v dc 10k 5v 0v v lo 2.5v dc v sync(+) v sync(-) v sync(-) v sync(+) rangemax inverters also available in dual output lxm1621-01 and quad output lxm1641-01 versions for multiple lamp applications. 4.99k 4.99k* 4.7f pwm signal from system LXM1611-01 brite 0 p.w. 100% of period 100s p.w. * use 4.99k for 5v pwm amplitude, 15k for 3.3v pwm amplitude, and omit for 2.5v pwm amplitude.
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