microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 1 copyright ? 2000 rev. 0.8, 2003-08-28 www. microsemi . com rangemax ? d igital d imming d ual l amp ccfl i nverter m odule p reliminary d ata s heet integrated products description the lxm1621 direct drive? ccfl (cold cathode fluorescent lamp) inverter modules are specifically designed for driving two lamp lcd backlight displays. similar to the lxm1620, the lxm1621 excels in applications where critical parameters include very wide range dimmability, high efficiency, and reliable fail-safe design in a small form factor. these 12 volt modules are specifically designed with desktop and industrial applications in mind. unlike the lxm1620 or any traditional dimming ccfl inverters, the lxm1621 provides the designer a vastly superior display brightness range. 100:1+ brightness range is achievable with a standard lcd display (see product highlight). our wide range dimming provides exceptional display readability at less than 1% of full brightness, allowing both power savings and low ambient light operating capability(i.e. ?night readable?). digital dimming provides flicker-free brightness control in any wide-range dimming application. incorporation of a video synch- ronization feature allows wide ratio dimming without the display disturbances and interference seen with competitive products. 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 the ?how rangemax works? section). the module design is based on a new direct drive topology, which provides a number of cost and performance advantages. linfinity?s multiple lamp inverters include a built in connector array for the most common lcd lamp configurations. other benefits of this new topology are fixed-frequency operation and secondary- side strike-voltage regulation. the lxm1621 is fully customizable (electronically and mechanically) to specific customer requirements. important: for the most current data, consult microsemi ?s website: http://www.microsemi.com key features ? rangemax wide range dimming ? 8v to 16v input voltage range ? small form factor ? easy to use brightness control ? microamp sleep mode ? output short-circuit protection and automatic strike-voltage regulation ? fixed frequency operation ? universal connector configuration applications ? hi-brite displays ? desktop displays ? low ambient light conditions (i.e. aircraft cabins, automobile) ? industrial applications benefits ? high efficiency reduces heating problems ? smooth, flicker free 0-100% 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 product highlight 1 2 3 w 1 2 3 w dc voltage source potentiometer u niversal d imming i nput v dc or p otentiometer module order info p art n umber l amp c urrent l amp run voltage (rms) LXM1621-01 7ma 500-750 lxm1621-02 6ma 350-550 lxm1621-03 6.5ma 350-550 lxm1621-04 5ma 470-640 l l x x m m 1 1 6 6 2 2 1 1 - - x x x x brite 1 2 3 w
microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 2 copyright ? 2000 rev. 0.8, 2003-08-28 www. microsemi . com rangemax ? d igital d imming d ual l amp ccfl i nverter m odule p reliminary d ata s heet integrated products absolute maximum ratings (note 1) input supply voltage (v in ).............................................................................................................................. ..-0.3v to 18v output voltage , no load....................................................................................................... i nternally limited to 1800v rms output current ................................................................................................................. .......10ma rms (internally limited) output power (per lamp) ........................................................................................................ .......................................... 6w input signal voltage (brite input)............................................................................................. ....................-0.3v to 6.5v input signal voltage ( sleep , v sync )............................................................................................................... -0.3v to v in ambient operating temp erature, zero airflow.................................................................................... ............... 0c to 70c storage temper ature range...................................................................................................... ....................... -40c to 85c note 1: exceeding these ratings could cause damage to the devi ce. all voltages are with resp ect to ground. currents are posi tive into, negative out of specified terminal recommended operating conditions this module has been designed to operate ove r 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 indicat e values beyond which the inverter, although operational, will not function optimally. recommended operating conditions parameter symbol min r.c. max units input supply voltage range (functional) v in 8 12 16 v input supply voltage (fully regulated lamp current) 10.2 12 13.8 v 4 5 w 2.5 3 w output power (per lamp) LXM1621-01 lxm1621-02 / 03 lxm1621-04 p o 2.75 3.5 w brightness control input voltage range v brt_adj 0.0 2.5 v 500 625 750 v rms 350 425 500 v rms lamp operating voltage LXM1621-01 lxm1621-02 / 03 lxm1621-04 v lamp 470 550 640 v rms 7.0 ma rms 6.0 ma rms 6.5 ma rms lamp current LXM1621-01 (full brightness ? per lamp) lxm1621-02 lxm1621-03 lxm1621-04 i olamp 5.0 ma rms operating ambient temperature range t a 0 70 c electrical characteristics unless otherwise specified, these specifications apply over the recommended operating conditions and 25c ambient temperature f or the lmx1621-xx. lxm1621-xx parameter symbol test conditions min typ max units ` output pin characteristics full brightness current LXM1621-01 v brt_adj = 2.5v dc , sleep = high, burst duty = 100%, v in = 12v dc 6.3 7.0 7.7 ma rms lxm1621-02 v brt_adj = 2.5v dc , sleep = high, burst duty = 100%, v in = 12v dc 5.5 6.0 6.5 ma rms lxm1621-03 v brt_adj = 2.5v dc , sleep = high, burst duty = 100%, v in = 12v dc 5.7 6.5 7.1 ma rms lxm1621-04 i l(max) v brt_adj = 2.5v dc , sleep = high, burst duty = 100%, v in = 12v dc 4.5 5.0 5.5 ma rms v brt_adj = 0v dc , sleep = high, burst duty = 2%, v in = 9v dc 0.14 ma rms minimum lamp current (per lamp) (notes 2 & 3) i l(min) v brt_adj = -50mv dc , sleep = high, burst duty =0.5%, v in = 9v dc 0.035 ma rms lamp start voltage v ls 0c < t a < 40c, v in > 10.8v dc 1500 1800 v rms operating frequency f o v brt_adj = 2.5v dc , sleep = high, v in = 12v dc 52 57 62 khz e e l l e e c c t t r r i i c c a a l l s s
microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 3 copyright ? 2000 rev. 0.8, 2003-08-28 www. microsemi . com rangemax ? d igital d imming d ual l amp ccfl i nverter m odule p reliminary d ata s heet integrated products electrical characteristics (continued) unless otherwise specified, these specifications apply over the recommended operating conditions and 25c ambient temperature f or the lmx1621-xx. lmx1621-xx parameter symbol test conditions min typ max units ` brite input input current i brt v brt_adj = 0v -6 -8 -10 a dc input voltage for max. lamp current v c i o(lamp) = 100% duty cycle 2.5 2.6 v dc i o(lamp) = 2% duty cycle 0 0 v dc input voltage for min. lamp current (note 3) v c i o(lamp) = 0.5% duty cycle -50 mv dc ` sleep input run mode (hi) sleep v 2.2 v in v dc sleep mode (lo) sleep v -0.3 0.8 v dc input current sleep i sleep = 5.0v 70 75 100 a dc ` v sync characteristics logic high level v sync(hi) 4.0 6.5 v dc logic low level v sync(lo) -0.3 1.0 v dc input impedance z in 60 66 75 k ? pulse width (note 4) t pw 25 250 s input frequency f sync 49 150 hz ` power characteristics sleep current i in(min) v in = 12v dc , sleep < 0.8v 5 50 a dc note 2: minimum lamp current required to maintain even light output may vary with display panel. note 3: see 200:1 dimming application section for details. note 4: the module will be functional with pulse widths much larger than 250s. functional pin description conn. pin description cn1 cn1-1 cn1-2 v in input power supply (8v < v in < 16v) cn1-3 cn1-4 gnd power supply return cn1-5 sleep on / off control. (2.2v < sleep < vin = on, -0.3v < sleep < 0.8v = off) cn1-6 brite brightness control (-0.3v to 2.5v dc ). 2.5v dc gives maximum lamp current. cn1-7, 8 vsync vertical synchronization input 49hz < f sync < 150hz cn2 thru cn5: refer to connection schematic section e e l l e e c c t t r r i i c c a a l l s s
microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 4 copyright ? 2000 rev. 0.8, 2003-08-28 www. microsemi . com rangemax ? d igital d imming d ual l amp ccfl i nverter m odule p reliminary d ata s heet integrated products physical dimensions LXM1621-01 / 02 / 03 1.50 in (38mm) 1.89 in (48mm) 1.26 in. (32mm) 4.88 in (124mm) w cn2, cn3 cn4 cn5 cn3 cn2 w cn5 w cn4 cn1 0.24 in (6mm) 0.34 in (8.6mm) backside connectors warning high voltage present at all output connectors weight: 23(g) typ. ? 0.12(3.0mm 0.08) grounded mounting hole - 2plcs 0.60 in (1.52mm) pcb tolerances 0.5mm lxm1621-04 1.50 in (38mm) 1.89 in (48mm) 1.26 in. (32mm) 4.88 in (124mm) cn2 cn3 w warning high voltage present at all output connectors weight: 23 (g) typ. cn1 backside connectors cn2, cn3 0.24 in 6mm ? 0.12(3.0mm 0.08) grounded mounting hole - 2plcs 0.60 in (1.52mm) pcb tolerances 0.5mm all dimensions are in inches (mm) m m e e c c h h a a n n i i c c a a l l s s
microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 5 copyright ? 2000 rev. 0.8, 2003-08-28 www. microsemi . com rangemax ? d igital d imming d ual l amp ccfl i nverter m odule p reliminary d ata s heet integrated products typical connection configurations cn1 cn4 cn5 l x m 1 6 2 1 - 0 1 / 0 2 / 0 3 ccfl lamps desktop display cn1 cn4 cn5 l x m 1 6 2 1 - 0 1 / 0 2 / 0 3 ccfl lamps desktop display cn1 cn4 cn5 l x m 1 6 2 1 - 0 1 / 0 2 / 0 3 ccfl lamps desktop display ccfl lamps desktop display cn1 cn2 cn3 l x m 1 6 2 1 - 0 1 / 0 2 / 0 3 cn1 cn2 cn3 l x m 1 6 2 1 - 0 4 ccfl lamps desktop display cn1 cn2 cn3 l x m 1 6 2 1 - 0 4 ccfl lamps desktop display * connectors cn2 and cn3 are on the bottom side of the inverter. view shown is looking through the board figure 1 ? connectivity configuration examples these examples illustrate six typical lcd wi ring configurations that are accommodated by linfinity?s unique connector array. linfinity inverters have multiple lamp connector styles that re common to the industry, which ar e duplicated at both ends of th e module. this permits over 14 va riations of module mounting and interconnectivity configuration. p p a a c c k k a a g g e e d d a a t t a a
microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 6 copyright ? 2000 rev. 0.8, 2003-08-28 www. microsemi . com rangemax ? d igital d imming d ual l amp ccfl i nverter m odule p reliminary d ata s heet integrated products connection schematic cn1 w cn4 w cn5 inverter output 1 inverter output 2 v hi1 v hi2 cn2 cn3 1 2 3 1 2 3 n.c. n.c. 1 2 3 4 4 3 2 1 w w figure 2a ? LXM1621-01 / 02 / 03 connection schematic cn1 w cn2 w cn3 inverter output 1 inverter output 2 v hi1 v hi2 1 2 3 3 2 1 figure 2b ? lxm1621-04 connection schematic connectors: mates with cn1 molex 53261-0890 pins: 50079-8100*, housing: 51021-0800 *loose(-8000, chain) recommended #26 awg wiring connection for LXM1621-01 / 02 / 03 cn2, cn3 jst sm04(4.0)b-bhs-1-tb jst bhr-04vs-1 cn4, cn5 jst sm03(4.0)b-bhs-1-tb jst bhr-03vs-1 connection for lxm1621-04 cn2, cn3 jst sm03(4.0)b-bhs-1-tb jst bhr-03vs-1 connection rules 1. always install two (2) lamps. operat ing with only one lamp may overdrive la mp current at maximu m brightness settings. 2. verify lamp wiring before connecting lamps to the inverter module. connectin g both lamps to one of the two inverter outpu t circuits will result in reduced brightness. the LXM1621-01 / 02 / 03 module connectors are wired per industry standard. the lamp hot wires (high voltage wires) are always on pin 1 or 2, a nd the cold wire (low voltage wire) is always on pin 3 or 4. 3. the lxm1621-04 uses the reverse pinout found in some panels. the lamp hot wires (high voltage wires) are on pins 2 and 3 and the cold (low voltage wire) is on pin 1. p p a a c c k k a a g g e e d d a a t t a a
microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 7 copyright ? 2000 rev. 0.8, 2003-08-28 www. microsemi . com rangemax ? d igital d imming d ual l amp ccfl i nverter m odule p reliminary d ata s heet integrated products how the rangemax works lamp voltage & lamp current ? burst mode operation figure 3 ? 50% burst duty cycle figure 4 ? 2% burst duty cycle rather than using the trad itional 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 3 of fi gure 5 photo at right, careful design consideration was given to controlling lamp start voltage to softly start current flow. th is eliminates current overshoot that can result in premature cath ode wear and reduce lamp life. figure 5 ? 2% burst duty cycle (expanded time base) ramp gen. transformer driver high voltage transformer comparator ramp + - i sense v sense v brite 0.25 - 2.2v dc v sync lamp v lo v hi lamp v lo v hi figure 6 ? rangemax simplified block diagram highlights ? integrated 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 about 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 synchronized to the video frame rate. this provides operation with no visible display disturbances caused by beat frequencies between the lamps and video frame rates. d d e e s s c c r r i i p p t t i i o o n n
microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 8 copyright ? 2000 rev. 0.8, 2003-08-28 www. microsemi . com rangemax ? d igital d imming d ual l amp ccfl i nverter m odule p reliminary d ata s heet integrated products how the rangemax works (continued) highlights (continued) ? in applications with no access to a vertical sync, the inverter burst frequency can be allowed to ?free run? at 95hz. in this non-synchronous mode, minor display disturbances may be found under certain video conditions. this performance is acceptable for many applications, but synchronization must be used when no disturbance can be tolerated. ? separate feedback loops for lamp current and open circuit voltage regulation insure reliable strike under all operating conditions, automatic over-voltage prevention with broken or failed lamps, and accurate lamp current regulation. 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 8. ? if synchronization to the video frame rate is desired, connect the vertical sync pu lse from the system video controller to the appropriate v sync input. if no video synchronization is desired, connect v sync to ground. ? 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). if both lamp wires have heavy high voltage insulation, connect the longest wire to v lo . v lo is connected directly to ground (gnd pin) on the inverter pcb. always insure a good lamp return by using a wire. do not rely on a chassis ground connection . rangemax inverters also available in single lamp inverters are the lxm1612-xx-xx or lxm1615-xx-xx, as well as the 12v dual lamp lxm1621-12-xx, lxm1622-xx-xx, and the quad output lxm1641-01 versions for multiple lamp applications. lxm1621-xx 12v v sync v sync gnd v hi1 v lo brite figure 7 - brightness control v in sleep 5v 0 < 10k 2.5v dc v hi2 p.w. < 100s brite lxm1621-xx 0 < p.w. < 100% of period pwm signal from system figure 8 - pwm brightness control 4.7f 4.99k* 4.99k * use 4.99k for 5v pwm amplitude, 15k for 3.3v pwm amplitude, and omit for 2.5v pwm amplitute. a a p p p p l l i i c c a a t t i i o o n n s s
microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 9 copyright ? 2000 rev. 0.8, 2003-08-28 www. microsemi . com rangemax ? d igital d imming d ual l amp ccfl i nverter m odule p reliminary d ata s heet integrated products wider dimming application the following application defines techniques capable of delivering dimming ranges in the 250:1 range. as is widely understood, these techniques will provide general capabilities and actual system performance will vary with panel design, ccfts, ambient temperature and a number of other variables outside the control of the inverter. these methods can be used in conjunction with other techniques such as lamp heating and matching. wide ratio (250:1) dimming can be accomplished using the linfinity inverter in two ways: 1. by varying the input voltage on the brightness pin as indicated in figure 9. caution must be exercised when applying negative voltage to the brightness control input. applying more then ?300mv to any inverter input will cause inverter malfunction (see absolute maximum ratings). -100mv 0v 2.5v .070 .14 0.7 7 v brt_adj (v) i olamp (ma) figure 9 ? average lamp current vs. v brite voltage (per lamp) cn2 c30 u9 t1 r58 c32 c33 r59 c35 r22 r48 r62 r63 r60 r31 r57 r55 r52 r54 r53 r56 r51 q11 r50 c39 r49 r89 c37 r61 q10 backside of module u7 figure 10 ? locating the resistor on the lxm1621-xx 2. by making a resistor value change on the module. remove r61 for maximum dimming range or increase r61 value to desired minimum dim range setting (see figure 10). care should be exercised since at a low enough dim setting the inverter will be unable to detect that the lamp has started and will initiate lamp strike (kickoff) voltage. this will result in lamp flicker. for repeatable low light levels the brite input dc supply must be a very clean stable voltage source, at low dim inputs. if you plan to completely remove r61 it is recommended tha t you ensure that a minimum voltage above zero remain on the brite input to prevent the above flicker problem. this minimum voltage may need to be adjusted for each individual inverter module. if you are using a pot to control the brite input then a separate trim pot on the low side would accomplish the same goal. both methods discussed will provide a lower duty cycle operation than is necessary in a 100:1 dimming application. careful consideration should be made with regard to display quality at these dimming levels. at very low brightness levels, even very small amounts of noise on the vbrite line can cause flicker on the display, so sp ecial care must be given to grounding, filtering, and shielding the inverter from the digital logic and clock signals. a a p p p p l l i i c c a a t t i i o o n n s s
microsemi linfinity microelectronics division 11861 western avenue, garden grove, ca. 92841, 714-898-8121, fax: 714-893-2570 page 10 copyright ? 2000 rev. 0.8, 2003-08-28 www. microsemi . com rangemax ? d igital d imming d ual l amp ccfl i nverter m odule p reliminary d ata s heet integrated products notes preliminary data ? information contained in thi s document is pre-production data and is proprietary to linfinity. it may not be 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. n n o o t t e e s s
|
