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general description the MAX9508 video filter amplifier with smartsleep and bidirectional video support is ideal for set-top boxes (stbs), portable dvd players, and portable media players (pmps). the inputs can be directly con- nected to the digital-to-analog converter (dac) outputs. the reconstruction filter removes high-frequency sig- nals above 6.75mhz. the amplifiers have 6db of gain, and the outputs can be dc-coupled to a load of 75 ? , which is equivalent to two video loads, or it can be ac-coupled to a load of 150 ? . the smartsleep circuitry intelligently reduces power consumption based on the presence of the input signal and the output loads. when the MAX9508 does not detect the presence of sync on the input video signal, the supply current is reduced to less than 7?. the device only enables a video amplifier when there is an active video input signal and an attached load. the video amplifier remains on while a load is connected. if the load is disconnected, the video amplifier is turned off. the MAX9508 contains three reconstruction filters, four video amplifiers, and a pulldown switch at one of the two cvbs outputs. the MAX9508 has the ability to con- trol the bidirectional video signals at the cvbs video connections without the need for separate switches or relays. this feature is particularly useful for portable dvd players, which often use the same connector to drive a composite video output and to accept an exter- nal video signal to display on the lcd panel. the MAX9508 operates from a 2.7v to 3.6v single supply and is offered in a small 16-pin tqfn (3mm x 3mm) package. the device is specified over the -40? to +125? automotive temperature range. applications set-top boxes (stbs) portable set-top boxes/ personal video recorders (pvrs) portable media players (pmps) portable dvd players portable applications features smartsleep feature detects input signal and output load status to reduce power consumption triple standard-definition video reconstruction filters with 6.75mhz passband luma, chroma, and composite inputs luma, chroma, and two composite outputs integrated support for a bidirectional composite video signal supports two video loads at each output (dc-coupled) 2.7v to 3.6v single-supply operation MAX9508 video filter amplifier with smartsleep and bidirectional video support ________________________________________________________________ maxim integrated products 1 ordering information 19-0531; rev 0; 5/06 for pricing, delivery, and ordering information, please contact maxim/dallas direct! at 1-888-629-4642, or visit maxim? website at www.maxim-ic.com. part pin-package pkg code top mark MAX9508ate+ 16 tqfn-ep** (3mm x 3mm) t1633-4 aem MAX9508aee+* 16 qsop e16-4 block diagrams note: all devices are specified over the -40? to +125? operat- ing temperature range. + denotes lead-free package. * future product?ontact factory for availability. ** ep = exposed pad. smartsleep is a trademark of maxim integrated products, inc. pin configurations appear at end of data sheet. cin yin extcvbsin cout yout cvbsout1 shdn int/ext active video detect smartsleep cvbsin cvbsout2 lpf control logic clamp buffer load sense 6db lpf buffer load sense buffer 6db load sense 6db load sense 6db lpf MAX9508 block diagrams continued at end of data sheet.
MAX9508 video filter amplifier with smartsleep and bidirectional video support 2 _______________________________________________________________________________________ absolute maximum ratings electrical characteristics (v dd = v shdn = 3.3v, v smartsleep = v int /ext = gnd = 0v, r l = no load. t a = t min to t max , unless otherwise noted. typical val- ues are at t a = +25?.) (note 1) stresses beyond those listed under ?bsolute maximum ratings?may cause permanent damage to the device. these are stress rating s only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specificatio ns is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. (voltages with respect to gnd.) v dd .......................................................................... -0.3v to +4v smartsleep, shdn , int /ext cin, yin, cvbsin, extcvbsin ..........................-0.3v to +4v duration of cout, yout, cvbsout1, cvbsout2 short circuit to v dd or gnd ..................................continuous continuous input current (cin, yin, extcvbsin, cvbsin, smartsleep, shdn , int /ext)...................................?0ma continuous power dissipation (t a = +70?) 16-pin tqfn (derate 15.6mw/? above +70?)..........1250mw 16-pin qsop (derate 8.3mw/? above +70?)...........667mw operating temperature range .........................-40? to +125? junction temperature ......................................................+150? storage temperature range .............................-65? to +150? lead temperature (soldering, 10s) .................................+300? parameter symbol conditions min typ max units supply voltage range v dd guaranteed by psrr 2.7 3.6 v int /e x t = g n d ( 4 channel s acti ve) , yin = cvbsin = 0.3v, cin = 0.6v 13 16 int /ext = v dd (1 channel active), extcvbsin is unconnected 4.3 6 ma smartsleep = v dd, cvbsin has no active video signal 714 supply current i dd smartsleep = v dd , cvbsin has a black- burst video signal with sync tip at gnd (note 2) 17 ? shutdown supply current i shdn v shdn = gnd 0.01 10 ? smartsleep characteristics minimum line frequency cvbsin 14.3 khz sync slice level cvbsin 4.1 5.2 % v dd output load detect threshold sync pulse present, r l to gnd 200 ? dc characteristics 2.7v < v dd < 3.6v 0 1.05 input-voltage range v in c in , y in , c v bs in , g uar anteed b y outp ut vol tag e sw i ng 3.0v < v dd < 3.6v 0 1.2 v input current i in cin = yin = cvbsin = 0v 2 5 ? input resistance r in cin, yin, cvbsin 20 m ?
MAX9508 video filter amplifier with smartsleep and bidirectional video support _______________________________________________________________________________________ 3 electrical characteristics (continued) (v dd = v shdn = 3.3v, v smartsleep = v int /ext = gnd = 0v, r l = no load. t a = t min to t max , unless otherwise noted. typical val- ues are at t a = +25?.) (note 1) parameter symbol conditions min typ max units sync-tip clamp level v clp extcvbsin 0.25 0.37 v inp ut c l am p i ng c ur r ent extcvbsin = 500mv + v clp 0.5 1 1.5 ? 2.7v < v dd < 3.6v 1.05 extcvbsin input voltage range guaranteed by output voltage swing 3.0v < v dd < 3.6v 1.2 v p-p sync crush extcvbsin, percentage reduction in sync pulse (0.3v p-p ), guaranteed by input clamping current measurement, measured at input 2% maximum input source resistance extcvbsin 300 ? dc voltage gain a v r l = 150 ? to v dd /2, 0v v in 1.05v, v dd = 2.7v 5.7 6 6.3 db dc gain matching r l = 150 ? to v dd /2, 0v v in 1.05v, v dd = 2.7v -0.2 0 +0.2 db yin = cvbsin = cin = 0v, int /ext = gnd, r l = 150 ? to gnd 0.21 0.3 0.38 output level c extcvbsin = 0.1? to gnd, int /ext = v dd, r l = 150 ? to gnd 0.21 0.27 0.38 v t a = -40? to +85? 2.027 2.1 2.163 measured at output, v dd = 2.7v, 0v v in 1.05v, r l = 150 ? to -0.2v t a = -40? to +125? 2.006 2.163 measured at output, v dd = 2.7v, 0v v in 1.05v, r l = 150 ? to v dd / 2 2.027 2.1 2.163 t a = -40? to +85? 2.316 2.4 2.472 measured at output, v dd = 3v, 0v v in 1.2v, r l = 150 ? to -0.2v t a = -40? to +125? 2.292 2.472 measured at output, v dd = 3v, 0v v in 1.2v, r l = 150 ? to v dd / 2 2.316 2.4 2.472 output voltage swing measured at output, v dd = 3.135v, 0v v in 1.05v, r l = 75 ? to -0.2v 2.027 2.1 2.163 v p-p output resistance r out v out = 1.3v, -5ma i load +5ma 0.47 ?
MAX9508 video filter amplifier with smartsleep and bidirectional video support 4 _______________________________________________________________________________________ electrical characteristics (continued) (v dd = v shdn = 3.3v, v smartsleep = v int /ext = gnd = 0v, r l = no load. t a = t min to t max , unless otherwise noted. typical val- ues are at t a = +25?.) (note 1) parameter symbol conditions min typ max units power-supply rejection ratio psrr 2.7v v dd 3.6v, input referred, r l = 150 ? to gnd 48 db output pulldown resistance r pd int /ext = v dd , cvbsout1 3.7 ? output shutdown impedance 28 k ? logic inputs (smartsleep, shdn , int /ext) logic-low threshold v il 0.3 x v dd v logic-high threshold v ih 0.7 x v dd v logic input current i il / i ih v i = 0v or v dd 0.01 10 ? ac electrical characteristics (v dd = v shdn = 3.3v, v smartsleep = v int /ext = gnd = 0v, r l = 150 ? to gnd. t a = t min to t max , unless otherwise noted. typical values are at t a = +25?.) (note 1) parameter symbol conditions min typ max units f = 5.5mhz -0.1 f = 6.75mhz -1 -0.3 +1 f = 11mhz -3 standard-definition reconstruction filter inputs are 1v p-p , reference frequency is 1mhz. f = 27mhz -33 -41 db dc-coupled output, 5-step modulated staircase f = 3.58mhz or 4.43mhz 0.2 differential gain dg ac-coupled output, 5-step modulated staircase f = 3.58mhz or 4.43mhz 0.4 % f = 3.58mhz 0.62 dc-coupled output, 5-step modulated staircase f = 4.43mhz 0.75 f = 3.58mhz 0.78 differential phase dp ac-coupled output, 5-step modulated staircase f = 4.43mhz 1.01 d eg r ees 2t pulse response 2t = 200ns or 250ns 0.2 k% 2t bar response bar time is 18?, the beginning 2.5% and the ending 2.5% of the bar time is ignored, 2t = 200ns or 250ns 0.2 k% 2t pulse-to-bar k rating bar time is 18?, the beginning 2.5% and the ending 2.5% of the bar time is ignored, 2t = 200ns or 250ns 0.3 k%
MAX9508 video filter amplifier with smartsleep and bidirectional video support _______________________________________________________________________________________ 5 note 1: all devices are 100% production tested at t a = +25?. specifications over temperature limits are guaranteed by design. note 2: specified current is an average over time. ac electrical characteristics (continued) (v dd = v shdn = 3.3v, v smartsleep = v int /ext = gnd = 0v, r l = 150 ? to gnd. t a = t min to t max , unless otherwise noted. typical values are at t a = +25?.) (note 1) parameter symbol conditions min typ max units nonlinearity 5-step staircase 0.1 % interchannel timing error difference in time between the 50% point of the output signals, yout to cout 0.2 ns group delay distortion 100khz f 5mhz, inputs are 1v p-p 10 ns interchannel group delay distortion error inputs are 1v p-p 2ns peak signal to rms noise 100khz f 5mhz, inputs are 1v p-p 67 db power-supply rejection ratio f = 100khz, 200mv p-p , input referred 43 db output impedance f = 5mhz 6 ? enable time yin = 1v, output settled to within 1% of the final voltage, r l = 150 ? to gnd 13 ? disable time yin = 1v, output settled to within 1% of the final voltage, r l = 150 ? to gnd 1.1 ? crosstalk all hostile output crosstalk f = 4.43mhz -70 db all hostile input crosstalk f = 4.43mhz, shdn = gnd, input termination resistors are 75 ? -69 db
MAX9508 video filter amplifier with smartsleep and bidirectional video support 6 _______________________________________________________________________________________ typical operating characteristics (v dd = shdn = +3.3v, v smartsleep = v int /ext = gnd = 0v. r l = 150 ? to gnd. t a = +25?, unless otherwise noted.) small-signal gain vs. frequency MAX9508 toc01 frequency (hz) output amplitude (db) 10m 1m -50 -40 -30 -20 -10 0 10 20 -60 100k 100m v out = 100mv p-p normalized to 1mhz small-signal gain flatness vs. frequency MAX9508 toc02 frequency (hz) output amplitude (db) 1m 10m -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 -1.0 100k 100m v out = 100mv p-p normalized to 1mhz large-signal gain vs. frequency MAX9508 toc03 frequency (hz) output amplitude (db) 10m 1m -50 -40 -30 -20 -10 0 10 20 -60 100k 100m v out = 2v p-p normalized to 1mhz large-signal gain flatness vs. frequency MAX9508 toc04 frequency (hz) output amplitude (db) 1m 10m -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 -1.0 100k 100m v out = 2v p-p normalized to 1mhz group delay MAX9508 toc05 frequency (hz) delay (ns) 10m 1m 0 25 50 75 100 125 150 -25 100k 100m v out = 2v p-p power-supply rejection ratio vs. frequency MAX9508 toc06 frequency (hz) psrr (db) 10m 1m 100k -70 -60 -50 -40 -30 -20 -10 0 -80 10k 100m quiescent supply current vs. temperature MAX9508 toc07 temperature ( c) supply current (ma) 100 75 50 25 0 -25 11.5 12.0 12.5 13.0 13.5 14.0 11.0 -50 125 voltage gain vs. temperature MAX9508 toc08 temperature ( c) voltage gain (v/v) 100 75 50 25 0 -25 1.96 1.97 1.98 2.00 1.99 2.01 2.02 1.95 -50 125 output voltage vs. input voltage MAX9508 toc09 input voltage (v) output voltage (v) 1.5 1.0 0.5 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 -0.5 -0.5 2.0 yin, cin, cvbsin inputs only
MAX9508 video filter amplifier with smartsleep and bidirectional video support _______________________________________________________________________________________ 7 differential gain and phase MAX9508 toc10 step differential phase (deg) differential gain (%) 5 4 3 2 -0.2 -0.1 0 0.1 0.2 0.3 -0.3 -0.8 -0.4 0 0.4 0.8 17 6 5 4 3 2 17 6 2t response MAX9508 toc11 100ns/div v in 200mv/div v out 400mv/div 12.5t response MAX9508 toc12 400ns/div y in 200mv/div y out 400mv/div ntc-7 video test signal on cvbs outputs MAX9508 toc13 10 s/div cvbsin 500mv/div cvbsout1 1v/div pal multiburst response MAX9508 toc14 10 s/div cvbsin 500mv/div cvbsout1 1v/div pal color bars MAX9508 toc15 10 s/div cvbsin 500mv/div cvbsout1 1v/div field square-wave response MAX9508 toc16 2ms/div cvbsin 500mv/div cvbsout1 1v/div enable time MAX9508 toc17 2 s/div output 1v/div shdn 1v/div input voltage = 1v disable time MAX9508 toc18 200ns/div output 1v/div shdn 1v/div input voltage = 1v typical operating characteristics (continued) (v dd = shdn = +3.3v, v smartsleep = v int /ext = gnd = 0v. r l = 150 ? to gnd. t a = +25?, unless otherwise noted.)
MAX9508 video filter amplifier with smartsleep and bidirectional video support 8 _______________________________________________________________________________________ pulldown resistance distribution MAX9508 toc19 pulldown resistance ( ? ) probability 5.5 5.0 4.0 4.5 2.0 2.5 3.0 3.5 1.5 1.0 6.0 pulldown resistance vs. temperature MAX9508 toc20 temperature ( c) pulldown resistance ( ? ) 100 75 25 50 0 -25 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 2.0 -50 125 frequency response at 6.75mhz distribution MAX9508 toc21 attenuation (db) probability -0.1 -0.2 -0.3 -0.4 -0.5 -0.6 0 frequency response at 27mhz distribution MAX9508 toc22 attenuation (db) probability -34 -36 -40 -38 -48 -46 -44 -42 -50 -52 -32 input-to-input crosstalk vs. frequency MAX9508 toc23 frequency (hz) crosstalk (db) 10m 1m -100 -80 -60 -40 -20 0 -120 100k 100m output-to-output crosstalk vs. frequency MAX9508 toc24 frequency (hz) crosstalk (db) 10m 1m -100 -80 -60 -40 -20 0 -120 100k 100m output impedance vs. frequency MAX9508 toc25 frequency (hz) output impedance ( ? ) 1m 10m 1 10 100 0.1 100k 100m typical operating characteristics (continued) (v dd = shdn = +3.3v, v smartsleep = v int /ext = gnd = 0v. r l = 150 ? to gnd. t a = +25?, unless otherwise noted.)
MAX9508 video filter amplifier with smartsleep and bidirectional video support _______________________________________________________________________________________ 9 pin description pin tqfn qsop name function 1, 13 3, 15 v dd power supply. bypass v dd with a 0.1? capacitor to ground. 2 4 yin luma video input. directly connect this input to the video dac output. 3, 8 5, 10 gnd ground 4 6 cvbsin internal cvbs signal input. directly connect this input to the video dac output. 57 extcvbsin external cvbs signal input. ac-couple the signal through a 0.1? capacitor to this input. 68 shdn active-low shutdown logic input. connect to logic low to place device in shutdown. connect to logic high for normal operation. 7 9 n.c. no connection. connect to gnd. 9 11 cvbsout2 cvbs output 2 10 12 cvbsout1 cvbs output 1. cvbsout1 is actively pulled to gnd when int /ext is logic high. 11 13 yout luma video output 12 14 cout chroma video output 14 16 int /ext internal/external cvbs logic input. connect int /ext low to process cvbs video signals from cvbsin input. connect int /ext high to process cvbs video signals from extcvbsin input. 15 1 smartsleep smartsleep logic input. connect to logic high to activate smartsleep operation. 16 2 cin chroma video input. directly connect this input to the video dac output. ep ep exposed pad. connect ep to gnd. ep is also internally connected to gnd.
detailed description in the typical application circuit for a portable dvd player (figure 1), the current dacs on a dvd decoder chip generate video signals. when the internal signal sources are selected, the MAX9508 filters those signals and then drives the video connectors through a 75 ? back termination resistor. when external video sources are selected, the MAX9508 selects the external com- posite video signal (extcvbsin), filters, and amplifies it. the output stages of the amplifiers connected to cout, yout, and cvbsout1 become high imped- ance. the n-channel switch at cvbsout1 turns on, thereby converting the back termination resistor into an input termination resistor. smartsleep feature the smartsleep feature is activated when the smartsleep input is connected to logic high. the smartsleep feature provides intelligent power management by selectively disabling the filters and output amplifiers based on the presence of video signals or loads attached to the MAX9508 video filter amplifier with smartsleep and bidirectional video support 10 ______________________________________________________________________________________ 75 ? current dac current dac current dac dvd chip svideo chroma svideo luma to y/c separation cvbs cin yin extcvbsin cout yout cvbsout1 int/ext active video detect cvbsin cvbsout2 lpf control logic microcontroller to tft lcd to tft lcd gnd +3.3v 0.1 f v dd clamp buffer load sense 6db 75 ? 75 ? 75 ? lpf buffer load sense buffer 6db load sense 6db 75 ? load sense 6db 75 ? lpf MAX9508 0.1 f shdn smartsleep +3.3v figure 1. typical application circuit for portable dvd player
MAX9508 video filter amplifier with smartsleep and bidirectional video support ______________________________________________________________________________________ 11 cvbs 1 cin yin extcvbsin cout yout cvbsout1 cvbsin cvbsout2 lpf gnd +3.3v v dd clamp off load sense 6db 75 ? 75 ? lpf buffer load sense buffer buffer 6db load sense 6db 75 ? load sense 6db 75 ? lpf MAX9508 7 a svideo chroma svideo luma current dac current dac no video signal current dac video encoder shdn int/ext active video detect smartsleep control logic +3.3v +3.3v off off off off off off off off off off off off off off cvbs 2 figure 2. standby mode outputs. if the smartsleep feature is not activated and the part is not in shutdown, the filters and output ampli- fiers completely turn on, regardless of whether there is a video signal at the cvbsin input and whether there are loads connected at the outputs. smartsleep only works with dc-coupled loads. standby mode in standby mode, the filters and output amplifiers are off and only the active video detect circuit is active. quiescent current consumption is approximately 7? (figure 2). the active video-detect circuit checks if sync is present on the cvbsin signal. if no sync is detected the device remains in standby mode.
MAX9508 active-detect mode the active video-detect circuit slices the cvbsin signal at 4.7% of the power supply (155mv for a 3.3v supply). if the transitions occur at a rate of 14khz or higher, a video signal is present. when the MAX9508 detects a video signal with sync at the cvbsin input, the control logic enters the active-detect mode and enables the load sense circuitry (figure 3). the supply current is typically 17?. if an output load is not connected to any amplifier, the MAX9508 remains in active-detect mode. eight times per second, each load-sense circuit checks for a load by connecting an internal 15k ? pullup resistor to the output for 1ms. if the output is pulled up, then no load is pre- sent. if the output stays low, a load is connected. video filter amplifier with smartsleep and bidirectional video support 12 ______________________________________________________________________________________ cvbs 1 cin yin extcvbsin cout yout cvbsout1 cvbsin cvbsout2 lpf gnd +3.3v v dd clamp off load sense 6db 75 ? 75 ? lpf buffer load sense buffer buffer 6db load sense 6db 75 ? load sense 6db 75 ? lpf MAX9508 17 a svideo chroma svideo luma no loads current dac current dac video signal present current dac video encoder shdn int/ext active video detect smartsleep control logic +3.3v +3.3v 0 to 50mv off off off off off off off off off off cvbs 2 figure 3. active-detect mode with no output loads
full-operation mode if a load is connected to an output, the corresponding filter and amplifier turn on and remain on until the out- put load is disconnected. in full-operation mode, smartsleep intelligently reduces the supply current based on the input signal presence and output loading. figures 4, 5, and 6 show which portions of the MAX9508 turn on and which remain off with different load configurations. when an amplifier is on, it continually checks if the load has been disconnected by detecting if the amplifier output is sourcing current during a horizontal line time. if no sourcing current is detected within one horizontal line time (approximately 64?), the load has been dis- connected and the amplifier returns to active-detect mode. if, at any time, the input video signal is removed, the MAX9508 returns to standby mode. if the smartsleep feature is not activated and the part is not in shutdown, the filters and amplifiers completely turn on, regardless of whether there is a video signal at the cvbsin input and whether there are loads connect- ed at the outputs. MAX9508 video filter amplifier with smartsleep and bidirectional video support ______________________________________________________________________________________ 13 cin yin extcvbsin cout yout cvbsout1 cvbsin cvbsout2 lpf gnd +3.3v v dd clamp off load sense 6db 75 ? 75 ? lpf buffer load sense buffer buffer 6db load sense 6db 75 ? load sense 6db 75 ? lpf MAX9508 2.9ma quiescent supply current plus output load current svideo chroma svideo luma cvbs1 75 ? current dac current dac video signal present current dac video encoder shdn int/ext active video detect smartsleep control logic +3.3v +3.3v 0 to 50mv off off off off off off off cvbs 2 figure 4. full-operation mode with cvbsout1 loaded
MAX9508 video filter amplifier with smartsleep and bidirectional video support 14 ______________________________________________________________________________________ cvbs 1 cin yin extcvbsin cout yout cvbsout1 cvbsin cvbsout2 lpf gnd +3.3v v dd clamp off load sense 6db 75 ? 75 ? lpf buffer load sense buffer buffer 6db load sense 6db 75 ? load sense 6db 75 ? lpf MAX9508 2.9ma quiescent supply current plus output load current svideo chroma svideo luma cvbs2 75 ? current dac current dac video signal present current dac video encoder shdn int/ext active video detect smartsleep control logic +3.3v +3.3v 0 to 50mv off off off off off off off figure 5. full-operation mode with cvbsout2 loaded
MAX9508 video filter amplifier with smartsleep and bidirectional video support ______________________________________________________________________________________ 15 cvbs1 cin yin extcvbsin cout yout cvbsout1 cvbsin cvbsout2 lpf gnd +3.3v v dd clamp off load sense 6db 75 ? 75 ? 75 ? lpf buffer load sense buffer buffer 6db load sense 6db 75 ? load sense 6db 75 ? lpf MAX9508 10.5ma quiescent supply current plus output load current svideo chroma 75 ? svideo luma 75 ? cvbs2 75 ? current dac current dac video signal present current dac video encoder shdn int/ext active video detect smartsleep control logic +3.3v +3.3v 0 to 50mv figure 6. full-operation mode with all outputs loaded
MAX9508 video filter amplifier with smartsleep and bidirectional video support 16 ______________________________________________________________________________________ internal mode versus external mode internal mode set the int /ext control input low for internal mode. the MAX9508 processes video signals from an internal source such as a dvd chip (figure 7). the 2:1 multi- plexer selects the video signal on cvbsin. the extcvbsin video signal is ignored. 75 ? current dac current dac current dac dvd chip svideo chroma svideo luma to y/c separation cvbs cin yin extcvbsin cout yout cvbsout1 shdn int/ext logic low active video detect smartsleep cvbsin cvbsout2 lpf control logic microcontroller to tft lcd to tft lcd +3.3v gnd +3.3v 0.1 f v dd clamp off buffer load sense 6db 75 ? 75 ? 75 ? lpf buffer load sense buffer 6db load sense 6db 75 ? load sense 6db 75 ? lpf MAX9508 0.1 f 13ma quiescent supply current figure 7. internal mode operation
external mode set the int /ext control input high for external mode. the 2:1 multiplexer selects the video signal on extcvbsin (figure 8). the yin, cin, and cvbsin sig- nals are ignored. the block drawing of the MAX9508 in figure 8 shows which circuits are off while in external mode. smartsleep does not function in external mode, and the smartsleep input is ignored. MAX9508 video filter amplifier with smartsleep and bidirectional video support ______________________________________________________________________________________ 17 75 ? current dac current dac current dac dvd chip svideo chroma svideo luma to y/c separation cvbs cin yin off off off off off off off off off off extcvbsin cout yout cvbsout1 shdn int/ext logic high active video detect smartsleep cvbsin cvbsout2 lpf control logic microcontroller to tft lcd to tft lcd +3.3v 0v or +3.3v gnd +3.3v v dd clamp buffer load sense 6db 75 ? 75 ? 75 ? 75 ? lpf buffer load sense buffer 6db load sense 6db 75 ? load sense 6db 75 ? lpf MAX9508 0.1 f 4.3ma quiescent supply current video source figure 8. external mode operation
MAX9508 inputs the MAX9508 video inputs yin, cin, and cvbsin should be directly connected to the output of the video current dac. dc-coupling ensures that the input sig- nals are ground referenced such that the sync tip of composite or luma signals is within 50mv of ground and the blank level of the chroma signal is between 0.5v and 0.65v. since the input buffer is identical for yin, cin, and cvbsin, any standard-definition video signal can be applied to those inputs as long as the signal is between ground and 1.05v when v dd = 2.7v. for example, three composite video signals could be applied to yin, cin, and cvbsin. the rgb set and the ypbpr set can also be inputs to yin, cin, and cvbsin (figure 9). the extcvbsin input can only handle signals with a sync pulse, such as composite, video, or luma. because the dc level of an external video input signal is unknown, the external video signal is ac-coupled through a 0.1? capacitor, and a sync tip clamp sets the internal dc level of the MAX9508. a 2:1 multiplexer under the control of the int /ext input selects either the signal at cvbsin or extcvbsin. video filter amplifier with smartsleep and bidirectional video support 18 ______________________________________________________________________________________ current dac current dac current dac video encoder pr/r pb/b y/g y/g cin yin extcvbsin cout yout cvbsout1 shdn int/ext active video detect smartsleep cvbsin cvbsout2 lpf control logic +3.3v +3.3v gnd +3.3v 0.1 f v dd clamp buffer load sense 6db 75 ? 75 ? lpf buffer pb/b y/g pr/r load sense buffer 6db load sense 6db 75 ? load sense 6db 75 ? lpf MAX9508 figure 9. y, p r , p b or rgb set applied to MAX9508
video reconstruction filter the MAX9508 filter passband is 6.75mhz, which makes the device suitable for the higher bandwidth video sig- nals from a dvd chip. broadcast video signals actually require less bandwidth because of channel limitations: ntsc signals have a 4.2mhz bandwidth, and pal sig- nals have a 5mhz bandwidth. video signals from a dvd player are not channel limited; therefore, the bandwidth of dvd video signals can push right against the nyquist limit of 6.75mhz. (recommendation itu-r bt.601-5 specifies 13.5mhz as the sampling rate for standard- definition video). therefore, the maximum bandwidth of the signal is 6.75mhz. to ease the filtering require- ments, most modern video systems oversample by two times; clocking the video current dac at 27mhz. outputs the video output amplifiers can both source and sink load current, allowing output loads to be dc- or ac- coupled. the amplifier output stage needs about 300mv of headroom from either supply rail. the MAX9508 has an internal level-shift circuit that positions the sync tip at approximately 300mv at the output. the blank level of the chroma output is positioned at approximately 1.3v if the blank level of the chroma input signal is 0.5v. the blank level of the chroma out- put is positioned at approximately 1.5v if the blank level of the chroma input signal is 0.6v. if the supply voltage is greater than 3.135v (5% below a 3.3v supply), each amplifier can drive two dc-cou- pled video loads to ground. if the supply is less than 3.135v, each amplifier can drive only one dc-coupled or ac-coupled video load. shutdown when shdn is low, the MAX9508 draws typically less than 10na supply current. all the amplifier outputs become high impedance. the effective output resis- tance at the video outputs is 28k ? , due to the internal feedback resistors to ground. applications information reducing power consumption in the video dacs yin, cin, and cvbsin have high-impedance input buffers and can work with source resistances as high as 300 ? . to reduce power dissipation in the video dacs, the dac output resistor can be scaled up in value. the reference resistor that sets the reference current inside the video dacs must also be similarly scaled up. for instance, if the output resistor is 37.5 ? , the dac must source 26.7ma when the output is 1v. if the output resis- tor is increased to 300 ? , the dac only needs to source 3.33ma when the output is 1v. there is parasitic capacitance from the dac output to ground. that capacitance in parallel with the dac out- put resistor forms a pole that can potentially roll off the frequency response of the video signal. for example, 300 ? in parallel with 50pf creates a pole at 10.6mhz. to minimize this capacitance, reduce the area of the signal trace attached to the dac output as much as possible, and place the MAX9508 as close to the video dac outputs as possible. ac-coupling the outputs the outputs can be ac-coupled since the output stage can source and sink current as shown in figure 10. coupling capacitors should be 220? or greater to keep the highpass filter formed by the 150 ? equivalent resistance of the video transmission line to a corner fre- quency of 4.8hz or below. the frame rate of pal sys- tems is 25hz, and the frame rate of ntsc systems is 30hz. the corner frequency should be well below the frame rate. MAX9508 video filter amplifier with smartsleep and bidirectional video support ______________________________________________________________________________________ 19
MAX9508 power-supply bypassing and ground the MAX9508 operates from a single-supply voltage down to 2.7v, allowing for low-power operation. bypass v dd to gnd with a 0.1? capacitor. place all external components as close to the device as possible. video filter amplifier with smartsleep and bidirectional video support 20 ______________________________________________________________________________________ current dac current dac current dac set-top box chip svideo chroma cin yin extcvbsin cout yout cvbsout1 shdn int/ext active video detect smartsleep cvbsin cvbsout2 lpf control logic gnd +3.3v gnd +3.3v 0.1 f v dd clamp off buffer load sense 6db 75 ? 220 f optional 75 ? lpf buffer load sense buffer 6db load sense 6db 75 ? load sense 6db 75 ? lpf MAX9508 svideo luma 220 f optional cvbs 1 220 f optional cvbs 2 220 f optional figure 10. ac-coupled outputs
MAX9508 video filter amplifier with smartsleep and bidirectional video support ______________________________________________________________________________________ 21 cin yin extcvbsin cout yout cvbsout1 shdn int/ext active video detect smartsleep cvbsin cvbsout2 lpf control logic clamp buffer load sense 6db lpf buffer load sense buffer 6db load sense 6db load sense 6db lpf MAX9508 0 to 50mv 300mv to 400mv block diagrams (continued)
MAX9508 video filter amplifier with smartsleep and bidirectional video support 22 ______________________________________________________________________________________ 16 15 14 13 12 11 10 9 1 2 3 4 5 6 7 8 smartsleep int/ext v dd cout yout cvbsout1 cvbsout2 gnd n.c. MAX9508 cin v dd cvbsin yin gnd extcvbsin shdn 15 16 14 13 5 6 7 gnd cvbsin 8 v dd cvbsout1 cvbsout2 cout 13 int/ext 4 12 10 9 smartsleep cin gnd n.c. shdn extcvbsin MAX9508 yin yout 2 11 v dd top view thin qfn (3mm x 3mm) qsop + + pin configurations chip information process: bicmos
MAX9508 video filter amplifier with smartsleep and bidirectional video support ______________________________________________________________________________________ 23 package information (the package drawing(s) in this data sheet may not reflect the most current specifications. for the latest package outline info rmation, go to www.maxim-ic.com/packages .) 12x16l qfn thin.eps 0.10 c 0.08 c 0.10 m c a b d d/2 e/2 e a1 a2 a e2 e2/2 l k e (nd - 1) x e (ne - 1) x e d2 d2/2 b l e l c l e c l l c l c package outline 21-0136 2 1 g 8, 12, 16l thin qfn, 3x3x0.8mm marking aaaa
MAX9508 video filter amplifier with smartsleep and bidirectional video support 24 ______________________________________________________________________________________ exposed pad variations 1.10 t1633-1 0.95 codes pkg. t1233-1 min. 0.95 nom. 1.10 d2 1.25 1.10 0.95 1.25 nom. 1.10 max. 1.25 min. 0.95 max. 1.25 e2 12 n k a2 0.25 ne a1 nd 0 0.20 ref - - 3 0.02 3 0.05 l e e 0.45 2.90 b d a 0.20 2.90 0.70 0.50 bsc. 0.55 3.00 0.65 3.10 0.25 3.00 0.75 0.30 3.10 0.80 16 0.20 ref 0.25 - 0 4 0.02 4 - 0.05 0.50 bsc. 0.30 2.90 0.40 3.00 0.20 2.90 0.70 0.25 3.00 0.75 3.10 0.50 0.80 3.10 0.30 pkg ref. min. 12l 3x3 nom. max. nom. 16l 3x3 min. max. 0.35 x 45 pin id jedec weed-1 0.35 x 45 weed-2 t1233-3 1.10 1.25 0.95 1.10 0.35 x 45 1.25 weed-1 0.95 t1633f-3 0.65 t1633-4 0.95 0.80 0.95 0.65 0.80 1.10 1.25 0.95 1.10 0.225 x 45 0.95 weed-2 0.35 x 45 1.25 weed-2 t1633-2 0.95 1.10 1.25 0.95 1.10 0.35 x 45 1.25 weed-2 no down bonds allowed yes no yes n/a no package outline 21-0136 2 2 g 8, 12, 16l thin qfn, 3x3x0.8mm yes weed-1 1.25 1.10 0.95 0.35 x 45 1.25 1.10 0.95 t1233-4 t1633fh-3 0.65 0.80 0.95 0.225 x 45 0.65 0.80 0.95 weed-2 n/a notes: 1. dimensioning & tolerancing conform to asme y14.5m-1994. 2. all dimensions are in millimeters. angles are in degrees. 3. n is the total number of terminals. 4. the terminal #1 identifier and terminal numbering convention shall conform to jesd 95-1 spp-012. details of terminal #1 identifier are optional, but must be located within the zone indicated. the terminal #1 identifier may be either a mold or marked feature. 5. dimension b applies to metallized terminal and is measured between 0.20 mm and 0.25 mm from terminal tip. 6. nd and ne refer to the number of terminals on each d and e side respectively. 7. depopulation is possible in a symmetrical fashion. 8. coplanarity applies to the exposed heat sink slug as well as the terminals. 9. drawing conforms to jedec mo220 revision c. 10. marking is for package orientation reference only. 11. number of leads shown are for reference only. 0.25 0.30 0.35 2 0.25 0 0.20 ref -- 0.02 0.05 0.35 8 2 0.55 0.75 2.90 2.90 3.00 3.10 0.65 bsc. 3.00 3.10 8l 3x3 min. 0.70 0.75 0.80 nom. max. tq833-1 1.25 0.25 0.70 0.35 x 45 no weec 1.25 0.70 0.25 package information (continued) (the package drawing(s) in this data sheet may not reflect the most current specifications. for the latest package outline info rmation, go to www.maxim-ic.com/packages .)
MAX9508 video filter amplifier with smartsleep and bidirectional video support maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim product. no circu it patent licenses are implied. maxim reserves the right to change the circuitry and specifications without notice at any time. maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 ____________________ 25 2006 maxim integrated products printed usa is a registered trademark of maxim integrated products, inc. heaney package information (continued) (the package drawing(s) in this data sheet may not reflect the most current specifications. for the latest package outline info rmation, go to www.maxim-ic.com/packages .) qsop.eps f 1 1 21-0055 package outline, qsop .150", .025" lead pitch

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