View LT1675-1-15_8964896.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

1 lt1675/lt1675-1 16751fb 250mhz, triple and single rgb multiplexer with amplifiers red 1 green 1 blue 1 red 2 green 2 blue 2 75 ? 75 ? 75 ? 75 ? cable cable cable v + v select rgb1/rgb2 1675 ta01 enable 75 ? 75 ? 75 ? 75 ? 75 ? 75 ? v out red 75 ? lt1675 75 ? v out green v out blue +1 +1 +2 +2 +2 +1 +1 +1 +1 high speed rgb mux rgb switching workstation graphics pixel switching coaxial cable drivers high speed signal processing the lt 1675 is a high speed rgb multiplexer designed for pixel switching and fast workstation graphics. included on chip are three spdt switches and three current feedback amplifiers. the current feedback ampli- fiers drive double-terminated 50 ? or 75 ? cables and are 100mhz pixel switching 3db bandwidth: 250mhz channel switching time: 2.5ns expandable to larger arrays drives cables directly high slew rate: 1100v/ s low switching transient: 50mv shutdown supply current: 100 a output short-circuit protected available in small 16-pin ssop package configured for a fixed gain of 2, eliminating six external gain setting resistors. the spdt switches are designed to be break-before-make to minimize unwanted signals cou- pling to the input. the lt1675-1 is a single version with two inputs, a single output and is ideal for a single channel application such as video sync. the key to the lt1675 fast switching speed is linear technology? proprietary high speed bipolar process. this mux can toggle between sources in excess of 100mhz, has a slew rate over 1000v/ s and has a ?db bandwidth of 250mhz. power supply requirements are 4v to 6v and power dissipation is only 300mw on 5v, or 100mw for the lt1675-1. the expandable feature uses the disable pin to reduce the power dissipation to near 0mw in the off parts. unlike competitive solutions that are in bulky high pin count packages, the lt1675 is in a 16-lead narrow body ssop. this small footprint, the size of an so-8, results in a very clean high performance solution. the lt1675-1 is available in the tiny msop and the so-8. red input 1 = 0vdc, red input 2 = 1vdc measured between 50 ? back termination and 50 ? load 500mv/div 1v/div 1675 ta02 0v red out 1v 0v logic input pin 10 3v clocking between 2 dc levels at 100mhz applicatio s u features typical applicatio u descriptio u , ltc and lt are registered trademarks of linear technology corporation. all other trademarks are the property of their respective owners.
2 lt1675/lt1675-1 16751fb absolute m axi m u m ratings w ww u supply voltage ..................................................... 6.3v inputs, enable and select, current ................ 20ma output short-circuit duration (note 2) ......... continuous specified temperature range ..................... 0 c to 70 c operating temperature range (note 3) .. 40 c to 85 c storage temperature range ................. 65 c to 150 c junction temperature (note 4) ............................ 150 c lead temperature (soldering, 10 sec).................. 300 c (note 1) package/order i n for m atio n w u u 1 2 3 4 5 6 7 8 top view gn package 16-lead plastic ssop narrow 16 15 14 13 12 11 10 9 v + v out red v out green v out blue v v select enable red 1 green 1 blue 1 gnd gnd red 2 green 2 blue 2 t jmax = 150 c, ja = 120 c/ w t jmax = 150 c, ja = 250 c/ w t jmax = 150 c, ja = 150 c/ w lt1675cms8-1 1 2 3 4 v in1 gnd v in2 v 8 7 6 5 v + enable v out select top view ms8 package 8-lead plastic msop 1 2 3 4 8 7 6 5 top view v + enable v out select v in1 gnd v in2 v s8 package 8-lead plastic so ms8 part marking ltgx s8 part marking 16751 order part number lt1675cs8-1 order part number consult ltc marketing for parts specified with wider operating temperature ranges. gn part marking 1675 order part number lt1675cgn order options tape and reel: add #tr lead free: add #pbf, lead free tape and reel: add #trpbf, lead free part marking: http://www.linear.com/leadfree/
3 lt1675/lt1675-1 16751fb electrical characteristics parameter conditions min typ max units output offset voltage any input selected 20 50 mv output offset matching between outputs r1 to r2, g1 to g2, b1 to b2 520 mv input current any input selected ?2 ?0 a input resistance v in = 1v 100 700 k ? psrr v s = 2.6v to 6v, measured at output 38 50 db dc gain error 0v to 1v v in = 1v, r l = 36 % v in = 1v, r l = 150 ? 48 % v in = 1v, r l = 75 ? 510 % dc gain error 0v to ?v v in = 1v, r l = 36 % v in = 1v, r l = 150 ? 48 % v in = 1v, r l = 75 ? 820 % output voltage v in = 2v, r l = 3.1 3.4 v v in = 2v, r l = 150 ? 2.7 3.0 v v in = 2v, r l = 75 ? 2.4 2.8 v v in = 2v, r l = 3.1 3.3 v v in = 2v, r l = 150 ? 2.6 3.0 v v in = 2v, r l = 75 ? 2.3 2.6 v disabled output impedance enable open 1.1 1.5 2.0 k ? maximum output current v in = 1v, v o = 0v 50 70 ma supply current lt1675 enable = 0v 25 33 42 ma enable = 4.7v 1 100 a lt1675-1 enable = 0v 81114 ma enable = 4.7v 0.3 33 a enable pin current lt1675 enable= 0v 450 600 a lt1675-1 enable= 0v 150 200 a select pin current lt1675 select = 0v 90 180 a lt1675-1 select = 0v 30 60 a select low select (see truth table) 0.8 v select high select (see truth table) 2v the denotes the specifications which apply over the specified temperature range, otherwise specifications are at t a = 25 c. v s = 5v, r l = , v in = 0v lt1675 (pins 1, 2, 3, 6, 7, 8), lt1675-1 (pins 1, 3), enable = 0v, unless otherwise specified.
4 lt1675/lt1675-1 16751fb ac characteristics parameter conditions min typ max units slew rate v out = 5v p-p 1100 v/ s full power bandwidth (note 5) v out =6v p-p 58 mhz small-signal ?db bandwidth less than 1db peaking 250 mhz gain flatness less than 0.1db 70 mhz gain matching r to g to b 0.10 db r1 to r2, g1 to g2, b1 to b2, lt1675-1 v in1 to v in2 0.01 db channel-to-channel select time r1 = 0v, r2 = 1v delay time measured from time select pin crosses logic threshold 5.0 ns switching time time for v out to go from 0v to 1v 2.5 ns enable time 10 ns disable time 100 ns input pin capacitance 2pf select pin capacitance lt1675 2.2 pf lt1675-1 1.5 pf enable pin capacitance lt1675 2.1 pf lt1675-1 1.5 pf output pin capacitance (disabled) enable open 4.4 pf small-signal rise time v in = 300mv p-p , r l = 100 ? 1.85 ns propagation delay v in = 300mv p-p , r l = 100 ? 3ns overshoot v in = 300mv p-p , r l = 100 ? 10 % on-channel to off-channel crosstalk measured at 10mhz 60 db chip disable crosstalk measured at 10mhz, enable open 90 db channel select output transient measured between back termination and load 50 mv p-p differential gain (note 6) 0.07 % differential phase (note 6) 0.05 deg lt1675cgn: t j = t a + (p d )(120 c/w) lt1675cms8-1: t j = t a + (p d )(250 c/w) lt1675cs8-1: t j = t a + (p d )(150 c/w) note 5: full power bandwidth is calculated from the slew rate measurement: fpbw = sr/2 v peak . note 6: differential gain and phase are measured using a tektronix tsg120 yc/ntsc signal generator and a tektronix 1780r video measurement set. the resolution of this equipment is 0.1% and 0.1 . nine identical muxs were cascaded giving an effective resolution of 0.011% and 0.011 . note 1: absolute maximum ratings are those values beyond which the life of a device may be impaired. note 2: may require a heat sink. note 3: the lt1675/lt1675-1 are guaranteed to meet specified performance from 0 c to 70 c and are designed, characterized and expected to meet these extended temperature limits, but are not tested at ?0 c and 85 c. guaranteed i grade parts are available; consult factory. note 4: t j is calculated from the ambient temperature t a and power dissipation p d according to the following formula: truth table lt1675 lt1675-1 select enable red out green out blue out vout 1 0 red 1 green 1 blue 1 vin1 0 0 red 2 green 2 blue 2 vin2 x 1 off off off off t a = 25 c. v s = 5v, r l = 150 ? , v in = 0v lt1675 (pins 1, 2, 3, 6, 7, 8), lt1675-1 (pins 1, 3), enable = 0v, unless otherwise specified.
5 lt1675/lt1675-1 16751fb typical perfor m a n ce characteristics uw frequency (hz) gain (db) 6.5 6.4 6.3 6.2 6.1 6.0 5.9 5.8 5.7 5.6 5.5 10k 1m 10m 100m 1675 g03 100k r l = 100 ? r g b gain vs frequency frequency (hz) gain (db) 6 5 4 3 2 1 0 ? ? ? ? 100k 10m 100m 1g 1675 g02 1m c l = 5pf c l = 3pf c l = 10pf r l = 150 ? c l = 0pf frequency response with capacitive loads frequency (hz) crosstalk rejection (db) 20 10 0 ?0 ?0 ?0 ?0 ?0 ?0 ?0 ?0 100k 10m 100m 1g 1675 g23 1m r s = 75 ? r l = 150 ? g1 driven r1 selected crosstalk rejection vs frequency crosstalk rejection vs frequency (disabled) 3db bandwidth vs supply voltage supply voltage ( v) 2 frequency (mhz) 300 280 260 240 220 200 180 160 140 120 100 3 4 1675 g04 5 6 r l = 150 ? frequency (hz) gain (db) phase (deg) 5 4 3 2 1 0 ? ? ? ? ? 0 ?0 ?0 ?0 ?0 100 120 140 160 180 200 100k 10m 100m 1g 1675 g01 1m phase gain c l = 0pf r l = 150 ? gain and phase vs frequency frequency (hz) 1m output voltage (v p-p ) 8 7 6 5 4 3 2 10m 100m 1g 1675 g08 v s = 5v r l = 150 ? undistorted output swing vs frequency frequency (hz) crosstalk rejection (db) ?0 ?0 ?0 ?0 ?0 ?0 ?0 100 ?10 120 ?30 100k 10m 100m 1g 1675 g05 1m r s = 75 ? r l = 150 ? r1 driven r2 selected crosstalk rejection vs frequency power supply rejection ratio vs frequency frequency (hz) crosstalk rejection (db) ?0 ?0 ?0 ?0 ?0 ?0 ?0 ?0 ?0 100 ?10 100k 10m 100m 1g 1675 g06 1m r s = 75 ? r l = 150 ? frequency (hz) power supply rejection ratio (db) 70 60 50 40 30 20 10 0 ?0 ?0 ?0 100k 10m 100m 1g 1675 g07 1m psrr +psrr v s = 5v t a = 25 c r l = 150 ?
6 lt1675/lt1675-1 16751fb typical perfor m a n ce characteristics u w output impedance vs frequency 2nd and 3rd harmonic distortion vs frequency frequency (mhz) 1 distortion (dbc) ?0 ?0 ?0 ?0 ?0 ?0 10 100 ltxxxx 1675 g10 r l = 150 ? v o = 2v p-p 2nd 3rd frequency (hz) output impedance ( ? ) 100k 10m 100m 1g 1675 g09 1m 10k 1k 100 10 1 disabled enabled temperature ( c) ?0 gain error (%) 12 10 8 6 4 2 0 25 75 1675 g15 ?5 0 50 100 125 v s = 5v v in = 1v r l = 75 ? r l = 150 ? temperature ( c) ?0 gain error (%) 100 1675 g14 050 4 3 2 1 0 25 25 75 125 v s = 5v v in = 1v r l = 75 ? r l = 150 ? temperature ( c) ?0 output short-circuit current (ma) 100 1675 g13 050 90 85 80 75 70 65 60 55 50 25 25 75 125 v s = 5v sourcing v in = 1v sinking v in = 1v output short-circuit current vs temperature output voltage vs input voltage supply current vs supply voltage input voltage (v) ? ? 0 2 input bias current ( a) 1 15 10 5 0 ? ?0 ?5 ?0 ?5 ?0 1675 g12 ? 3 v s = 5v 125 c ?5 c 25 c input bias current vs input voltage negative dc gain error vs temperature positive dc gain error vs temperature lt1675-1 supply current vs supply voltage input voltage (v) ? output voltage (v) 4 3 2 1 0 ? ? ? ? 2 1675 g16 ? 0 1 v s = 5v t a = 25 c r l = 75 ? r l = r l = 150 ? supply voltage ( v) 01 supply current (ma) 24 3 5 6 1675 g11 40 35 30 25 20 15 10 5 0 r l = 125 c ?5 c 25 c supply voltage ( v) 01 supply current (ma) 24 3 5 6 1675 g24 14 12 10 8 6 4 2 0 r l = 125 c ?5 c 25 c
7 lt1675/lt1675-1 16751fb typical perfor m a n ce characteristics u w temperature ( c) ?0 input bias current ( a) ?0 ?1 ?2 ?3 25 75 1675 g17 ?5 0 50 100 125 v s = 5v v in = 0v input bias current vs temperature output offset voltage vs temperature temperature ( c) 20 15 10 5 0 1675 g18 output offset voltage (mv) v s = 5v ?0 25 75 ?5 0 50 100 125 0v v out v gen r l = 100 ? measured with fet probes 1675 g21 50mv/div 50mv/div small-signal rise time 5v 0v 0v enable pin 9 red out pin 15 enable and disable of uncorrelated sinewave r l = 150 ? 1675 g22 2v/div 2v/div 3v red 1 = 0v red 2 = uncorrelated sinewave r l = 150 ? , 10pf scope probe 1675 g19 1v/div 1v/div red 1 in red out pin 15 measured at pin 15 r l = 150 ? , 10pf scope probe sr = 1100v/ s 1675 g20 1v/div 2v/div 0v select pin 10 red out pin 15 toggling red 2 to red 1 slew rate enable and disable
8 lt1675/lt1675-1 16751fb pi n fu n ctio n s uuu select (pin 10): channel select. use this pin to select between rgb1 inputs and rgb2 inputs. use this pin for fast toggling. high selects rgb1. v (pins 11, 12): negative power supply. connect these pins to 5v and bypass with a good tantalum capacitor (4.7 f). the pin may also require a 0.1 f or 0.01 f depending on layout. v out blue (pin 13): blue output. it is twice blue 1 or blue 2 depending on which channel is selected by pin 10. v out blue drives 50 ? or 75 ? double-terminated cables. do not add capacitance to this pin. v out green (pin 14): green output. it is twice green 1 or green 2 depending on which channel is selected by pin 10. v out green drives 50 ? or 75 ? double-terminated cables. do not add capacitance to this pin. v out red (pin 15): red output. it is twice red 1 or red 2 depending on which channel is selected by pin 10. v out red drives 50 ? or 75 ? double-terminated cables. do not add capacitance to this pin. v + (pin 16): positive power supply. connect this pin to 5v and bypass with a good tantalum capacitor (4.7 f). the pin may also require a 0.1 f or 0.01 f depending on layout. v out (pin 6): it is twice v in1 or v in2 depending on which channel is selected by pin 5. v out drives 50 ? or 75 ? double-terminated cables. do not add capacitance to this pin. enable (pin 7): ground this pin for normal operation. take this pin to within 300mv of v + , or open to shut down the part. this pin is also used for router applications. when the part is disabled, the supply current is 0.3 a. v + (pin 8): connect this pin to 5v and bypass with a good tantalum capacitor (4.7 f). the pin may also require a 0.1 f or 0.01 f depending on layout. lt1675-1 v in1 (pin 1): the 1v video input signal to be switched is applied to this pin. if 2v is applied to this pin, v out will clip. the input must be terminated. gnd (pin 2): signal ground. connect to ground plane. v in2 (pin 3): the 1v video input signal to be switched is applied to this pin. if 2v is applied to this pin, v out will clip. the input must be terminated. v (pin 4): connect this pin to 5v and bypass with good tantalum capacitor (4.7 f). the pin may also require a 0.1 f or 0.01 f depending on layout. select (pin 5): use this pin to select v in1 or v in2 . use this pin for fast toggling. high selects v in1 . lt1675 red 1 (pin 1): red 1 input. the 1v video input signal to be switched is applied to this pin. if 2v is applied to this pin, v out red will clip. the input must be terminated. green 1 (pin 2): green 1 input. the 1v video input signal to be switched is applied to this pin. if 2v is applied to this pin, v out green will clip. the input must be terminated. blue 1 (pin 3): blue 1 input. the 1v video input signal to be switched is applied to this pin. if 2v is applied to this pin, v out blue will clip. the input must be terminated. gnd (pins 4, 5): signal ground. connect to ground plane. red 2 (pin 6): red 2 input. the 1v video input signal to be switched is applied to this pin. if 2v is applied to this pin, v out red will clip. the input must be terminated. green 2 (pin 7): green 2 input. the 1v video input signal to be switched is applied to this pin. if 2v is applied to this pin, v out green will clip. the input must be terminated. blue 2 (pin 8): blue 2 input. the 1v video input signal to be switched is applied to this pin. if 2v is applied to this pin, v out blue will clip. the input must be terminated. enable (pin 9): chip enable. ground this pin for normal operation. take this pin to within 300mv of v + , or open to shut down the part. this pin is also used for router applications. when the part is disabled, the supply current is 1 a.
9 lt1675/lt1675-1 16751fb applicatio n s i n for m atio n wu u u power supplies the lt1675 will function with supply voltages below 2v (4v total), however, to ensure a full 1v p-p video signal (2v p-p at the output pins), the power supply voltage should be between 4v to 6v. the lt1675 is designed to operate on 5v, and at no time should the supplies exceed 6v. the power supplies should be bypassed with quality tantalum capacitors. it may be necessary to add a 0.01 f or 0.1 f in parallel with the tantalum capacitors if there is excessive ringing on the output waveform. even though the lt1675 is well behaved, bypass capacitors should be placed as close to the lt1675 as possible. smallest package and pc board space the lt1675 has the internal gain set for + 2v/v or 6db, because it is designed to drive a double-terminated 50 ? or 75 ? cable that has an inherent 6db loss. there are several advantages to setting the gain internally. this topology eliminates six gain set resistors, reduces the pin count of the package and eliminates stray capacitance on the sensitive feedback node. the lt1675 fits into the small ssop package, and these advantages lead to the smallest pc board footprint with enhanced performance. the lt1675-1 eliminates two gain set resistors and is available in the tiny msop package and the cost-effective so-8 package. fast switching the key to the lt1675 fast switching speed is linear technology? proprietary high speed bipolar process. internal switches can change state in less than 1ns, but the output of the mux switches in about 2.5ns, as shown in figure 1. the additional delay is due to the finite bandwidth and the slew rate of the current feedback amplifier that drives the cable. for minimum ringing, it is important to minimize the load capacitance on the output of the part. this is normally not a problem in a controlled impedance environment, but stray pc board capacitance and scope probe capacitance can degrade the pulse fidelity. figure 2 shows the response of the output to various capacitive loads mea- sured with a 10pf scope probe. measured at pin 15 r l = 150 ? , 10pf scope probe 1675 f02 c l = 20pf c l = 10pf c l = 0pf 2v/div figure 2. response to capacitive loads 1v/div 500mv/div 0v 3v select pin 10 red out pin 15 red 1 = 1v, red 2 = 0v measured between 75 ? back termination and 75 ? load 1675 f01 figure 1. toggling at 25mhz
10 lt1675/lt1675-1 16751fb applicatio n s i n for m atio n wu u u switching transients this mux includes fast current steering break-before- make spdt switches that minimize switching glitches. the switching transients of figure 3 are input-referred (measured between 75 ? back termination and the 75 ? load). the glitch is only 50mv p-p and the duration is just 5ns. this transient is small and fast enough to not be visible on quality graphics terminals. additionally, the break-before-make spdt switch is open before the alter- nate channel is connected. this means there is no input feedthrough during switching. figure 4 shows the amount of alternate channel that is coupled at the input. expanding inputs in video routing applications where the ultimate speed is not mandatory, as it is in pixel switching, it is possible to expand the number of mux inputs by shorting the lt1675 outputs together and switching with the enable pins. the internal gain set resistors have a nomi- nal value of 750 ? and cause a 1500 ? shunt across the 75 ? cable termination. figure 5 shows schematically the effect of expanding the number of inputs. the effect of this loading is to cause a gain error that can be calculated by the following formula: gain n n db error (db) = 6db + 20log ? 75 + 1575 ? 75 1575 75 ? ? ? ? ? ? ? ? ? ? ? ? ? ? where n is total number of lt1675s. for example, using ten lt1675s (20 red, 20 green and 20 blue) the gain error is only 1.7db per channel. figure 6 shows a 4-input rgb router. the response from red 1 input to red output is shown in figure 7 for a 25mhz square wave with chip select = 0v. in this case the gain error is 0.23db. toggling with chip select between ic #1 and ic #2 is shown in figure 8. in this case red 1 input is connected to 0v and red 3 input is connected to an uncorrelated sinewave. 0v 3v 1v/div 0v select pin 10 50mv/div red out pin 15 r l = 150 ? , 10pf scope probe 1675 f03 figure 3. input-referred switching transient r s = 75 ? 1675 f04 3v 0v 0v 1v/div 20mv/div red 1 in pin 1 select pin 10 figure 4. switching transient at red 1 (pin 1)
11 lt1675/lt1675-1 16751fb applicatio n s i n for m atio n wu u u cable 75 ? r2 75 ? 1675 f05 750 ? 75 ? 750 ? off 750 ? 75 ? 750 ? off 750 ? r1 75 ? 75 ? 750 ? on n . . . ? 1575 n ?1 n = number of lt1675s in parallel figure 5. off channels load the cable termination with 1575 ? each 0v 500mv/div 0v 1v 1v red 1 input 500mv/div red output chip select = 0v, ic #2 disabled 1675 f07 figure 7. 4-input router response figure 6. two lt1675s build a 4-input rgb router r1 r2 r3 r4 chip select 1675 f06 enable lt1675 #1 75 ? a v = 2 lt1675 #2 74hc04 enable 75 ? red out a v = +2 75 ? 5v 0v 0v red output chip select 5v/div 1v/div red 1 input = 0v 1675 f08 red 3 input = uncorrelated sinewave figure 8. 4-input router toggling
12 lt1675/lt1675-1 16751fb typical applicatio s u rgb video inverter red video in green blue 75 ? 75 ? 75 ? 75 ? cable cable cable v + v select 1675 ta03 enable composite blanking 97.6 ? 97.6 ? 97.6 ? v out red 75 ? lt1675 75 ? v out green v out blue +1 +1 +2 +2 +2 +1 +1 +1 +1 332 ? 332 ? + 332 ? 332 ? + 332 ? 10k 10k lt1634 lt1399 5v 0.714v 1.25v 332 ? + this circuit is useful for viewing photographic negatives on video. a single channel can be used for composite or monochrome video. the inverting amplifier stages are only switched in during active video so the blanking, sync and color burst (if present) are not disturbed. to prevent video from swinging negative, a voltage offset equal to the peak video signal is added to the inverted signal.
13 lt1675/lt1675-1 16751fb typical applicatio s u logo or ?ug?inserter red video in green blue 113 ? 75 ? 75 ? 75 ? cable cable cable v + v select select a select b 1675 ta05 enable 75 ? 75 ? 75 ? v out red 113 ? lt1675 113 ? v out green v out blue +1 +1 +2 +2 +2 +1 +1 +1 +1 226 ? v + v select enable 226 ? lt1675 b a 226 ? +1 +1 +2 +2 +2 +1 +1 +1 +1 10k 10k lt1634 5v 0.714v 1.25v select a 0 0 1 1 select b 0 1 0 1 output no video, 100% white video plus 66% white video plus 33% white video, no white set the relative bit weights. the output of the lt1675 labeled b in the schematic is one half the weight of the a device. to properly match the 75 ? video cable, the output resistors are selected so the parallel combination of the two is 75 ohms. the output will never exceed peak white, which is 0.714v for this ntsc-related rgb video. the reference white signal is adjustable to lower than peak white to make the effect less intrusive, if desired. this circuit highlights a section of the picture under control of a synchronous key signal. it can be used for adding the logo (also called a ?ug? you see in the bottom corner of commercial television pictures or any sort of overlay signal, such as a crosshair or a reticule. the key signal has 2 bits of control so there can be four levels of highlighting: unmodified video, video plus 33% white, video plus 66% white and 100% white. the two lt1675s are configured as a 2-bit dac. the resistors on the outputs
14 lt1675/lt1675-1 16751fb si plified sche atic w w (lt1675-1, lt1675 one channel) red 1 gnd select enable v 1675 ss v + 750 ? 750 ? red v out red 2 v v v + v + logic off +
15 lt1675/lt1675-1 16751fb information furnished by linear technology corporation is believed to be accurate and reliable. however, no responsibility is assumed for its use. linear technology corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. package descriptio n u dimensions in inches (millimeters) unless otherwise noted. s8 package 8-lead plastic small outline (narrow 0.150) (ltc dwg # 05-08-1610) 1 2 3 4 0.150 ?0.157** (3.810 ?3.988) 8 7 6 5 0.189 ?0.197* (4.801 ?5.004) 0.228 ?0.244 (5.791 ?6.197) 0.016 ?0.050 0.406 ?1.270 0.010 ?0.020 (0.254 ?0.508) 45 0 ?8 typ 0.008 ?0.010 (0.203 ?0.254) so8 0996 0.053 ?0.069 (1.346 ?1.752) 0.014 ?0.019 (0.355 ?0.483) 0.004 ?0.010 (0.101 ?0.254) 0.050 (1.270) typ dimension does not include mold flash. mold flash shall not exceed 0.006" (0.152mm) per side dimension does not include interlead flash. interlead flash shall not exceed 0.010" (0.254mm) per side * ** gn package 16-lead plastic ssop (narrow 0.150) (ltc dwg # 05-08-1641) gn16 (ssop) 0398 * dimension does not include mold flash. mold flash shall not exceed 0.006" (0.152mm) per side ** dimension does not include interlead flash. interlead flash shall not exceed 0.010" (0.254mm) per side 0.016 ?0.050 (0.406 ?1.270) 0.015 0.004 (0.38 0.10) 45 0 ?8 typ 0.007 ?0.0098 (0.178 ?0.249) 0.053 ?0.068 (1.351 ?1.727) 0.008 ?0.012 (0.203 ?0.305) 0.004 ?0.0098 (0.102 ?0.249) 0.025 (0.635) bsc 12 3 4 5 6 7 8 0.229 ?0.244 (5.817 ?6.198) 0.150 ?0.157** (3.810 ?3.988) 16 15 14 13 0.189 ?0.196* (4.801 ?4.978) 12 11 10 9 0.009 (0.229) ref ms8 package 8-lead plastic msop (ltc dwg # 05-08-1660) msop (ms8) 1197 * dimension does not include mold flash, protrusions or gate burrs. mold flash, protrusions or gate burrs shall not exceed 0.006" (0.152mm) per side ** dimension does not include interlead flash or protrusions. interlead flash or protrusions shall not exceed 0.006" ( 0.152mm ) per side 0.021 0.006 (0.53 0.015) 0 ?6 typ seating plane 0.007 (0.18) 0.040 0.006 (1.02 0.15) 0.012 (0.30) ref 0.006 0.004 (0.15 0.102) 0.034 0.004 (0.86 0.102) 0.0256 (0.65) typ 12 3 4 0.192 0.004 (4.88 0.10) 8 7 6 5 0.118 0.004* (3.00 0.102) 0.118 0.004** (3.00 0.102)
16 lt1675/lt1675-1 16751fb lt/lt 0605 rev b ? printed in usa ? linear technology corporation 1998 linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7417 (408) 432-1900 fax: (408) 434-0507 www.linear.com typical applicatio n u related parts part number description comments lt6555 650 mhz rgb multiplexing amplifier 2200v/ s slew rate, 2:1 input mux lt1203/lt1205 150mhz video mux 2-input and 4-input, 90db channel separation, wide supply range lt1204 4-input video mux with 75mhz current feedback amp drives cables, adjustable gain, 90db channel separation lt1260 low cost dual and triple 130mhz current feedback amp drives cables, wide supply range, 0 a shutdown current with shutdown lt1398/lt1399 low cost dual and triple 300mhz current feedback amp performance upgrade for the lt1259/lt1260 with shutdown ntsc-related color bar generator qa qb qc clk clr load enp 5v ent a 5v clock is subcarrier 4 divided by 91 or 157.343khz b c d 75 ? 75 ? 75 ? 75 ? cable cable cable v + v select 1675 ta04 enable composite sync composite blanking 1k 1k 1k v out blue 75 ? lt1675 75 ? v out red v out green +1 +1 +2 +2 +2 +1 +1 +1 +1 6.04k 6.04k r 6.04k b g 640 ? 10k ?v 0.285v 74act04 74ls163 white yellow cyan green magenta red blue black 0 b 0.714v 0 r 0.714v 0 g 0.714v an rgb color bar test pattern is easily generated by dividing down a suitable clock. to form a stable pattern, the clock must be synchronous with the horizontal scan rate. four times subcarrier, or 14.318mhz, is a readily available frequency, which when divided by 91, gives 157.343khz. dividing this signal by two, four and eight, gives the blue, red and green signals, respectively. this timing gives eight bars including white and black that fill the 52.6 s active video time. the digital signals are run through a 74act04 inverter because the cmos output swings rail-to-rail. the inverter output is scaled to make video (0.714v peak, for ntsc-related rgb). the lt1675 drives the cable and adds sync to the rgb signals by switching in ?.286v. if no sync is required, this voltage can be set to zero and composite blanking can be used to drive the select pin of the lt1675 in order to provide a more precise blanking level.

▲Up To Search▲

Price & Availability of LT1675-1-15

	To Download LT1675-1-15 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .