www.fairchildsemi.com rev. 1c april 2004 features 6.7mhz y and c ?ters, with cv out for ntsc or pal ?5 ? cable line driver for y, c, cv, and tv modulator 43db stopband attenuation at 27mhz 1db ?tness up to 4.8mhz no external frequency select components or clocks 12ns group delay ?tness up to 10mhz 5% overshoot on any input edge ? c coupled input and output (ml6428cs-1) ? c coupled input and dc coupled output (ml6428cs-2) 0.4% differential gain on all channels, 0.4?differential phase on all channels 0.7% total harmonic distortion on all channels 5v ?0% operation dc restore with low tilt general description the ml6428 is a dual y/c 4th-order butterworth lowpass video ?ter optimized for minimum overshoot and ?t group delay. the device also contains a summing circuit to gener- ate ?tered composite video. the y and c input signals from dacs are ac coupled into the ml6428. both channels have dc restore circuitry to clamp the dc input levels during video sync. the y channel uses a sync tip clamp. the cv and the c channels share a feedback clamp. all outputs must be ac coupled into their loads for the -1 v ersion. the -2 version must be dc coupled. all inputs (-1 and -2 versions) are ac coupled. the y or c outputs can drive 2vp-p into a 150 ? load, while the cv output can drive 2vp-p into 75 ? . thus the cv output is capable of driving two independent 150 ? loads to 2vp-p. on the cv output, one of the 75 ? loads can be shorted to ground with no loss of drive to the remaining load. the y, c and cv channels have a gain of 2 (6db) with 1vp-p input levels. block diagram buffer buffer transconductance error amp buffer sync tip clamp 4th-order filter 4th-order filter 4 1 3 8 6 5 gnd cin yin yout cvout cout vcco vcc 7 2 + + ml6428 s-video filter and 75 ? line drivers with summed composite output
ml6428 data sheet 2 rev. 1c april 2004 pin con?uration pin description electrical characteristics absolute maximum ratings absolute maximum ratings are those values beyond which the device could be permanently damaged. absolute maximum ratings are stress ratings only and functional device operation is not implied. operating conditions pin name function 1 yin luminance input 2 vcc 5v supply for filters and references 3 gnd ground 4 cin chrominance input 5 cout chrominance output 6c v out composite video output 7 vcco 5v supply for output stages 8y out luminance output p arameter min. max. units dc supply voltage -0.3 7 v analog & digital i/o gnd ?0.3 v cc + 0.3 v output current (continuous) cv channel c and y channels 60 30 ma ma junction temperature 150 ? storage temperature range ?5 150 ? lead temperature (soldering, 10 sec) 260 ? thermal resistance ( ja )6 7 ?/w p arameter min. max. units temperature range 0 70 c vcc range 4.5 5.5 v ml6428 8-pin soic (s08) 1 2 3 4 8 7 6 5 yin vcc gnd cin yout vcco cvout cout top view
data sheet ml6428 rev. 1c april 2004 3 electrical table unless otherwise speci?d, v cc = 5v ?0%, all inputs ac coupled with 100nf, ml6428-1 outputs must be ac coupled, ml6428-2 outputs must be dc coupled. t a = operating temperature range 1 note 1: limits are guaranteed by 100% testing, sampling, or correlation with worst case test conditions. 2: sustained short circuit protection limited to 10 seconds. symbol parameter conditions min. typ. max. units icc supply current no load (vcc = 5.0v) 52 80 ma av low frequency gain (all channels) vin = 100mvp-p at 300khz 5.34 6.0 6.65 db c dc output level (during sync) sync present on y 1.7 1.9 2.3 v y sync output level ml6428-1 sync present on y 0.7 0.9 1.3 v ml6428-2 sync present on y 0.35 0.54 0.95 v y+c sync output level ml6428-1 sync present on y 0.7 0.92 1.3 v ml6428-2 sync present on y 0.35 0.48 0.95 v tclamp clamp response time (y channel) settled to within 10mv 2 ms f1db -1db bandwidth (flatness) (all channels) 4.0 4.8 mhz fc -3db bandwidth (flatness) (all channels) 6.7 mhz 0.8fc 0.8 x fc attenuation (y, c) 1.5 db fsb stopband rejection (all channels) fin = 27mhz to 100mhz worst case ?2 ?8 db vi input signal dynamic range ac coupled ml6428-1, -2 1.0 1.4 vp-p noise output noise (all channels) 25hz to 50mhz 2.3 mvrms os peak overshoot (all channels) 2vp-p output pulse (loaded) 4.3 % isc output short circuit current (all channels) vout c, y, or cv (note 2) 100 ma cl output shunt capacitance (all channels) all outputs 35 pf dg differential gain (all channels) all outputs 0.4 % d differential phase (all channels) all outputs 0.4 thd output distortion (all channels) vout = 1.8vp-p, y/c out at 3.58mhz/4.43mhz 0.7 % xtalk crosstalk from c input of 0.5vp-p at 3.58mhz/4.43mhz, to y output ?5 db from y input of 0.4vp-p at 3.58mhz, to c output ?8 db psrr psrr (all channels) 0.5vp-p (100khz) at vcc ?9 db tpd group delay (all channels) 100khz 60 ns ? tpd group delay deviation from flatness (all channels) to 3.58mhz (ntsc) 4 ns to 4.43mhz (pal) without peaking (see figures 7 to 11) 7ns to 10mhz 12 ns tskew skew between y & c outputs 1 ns
ml6428 data sheet 4 rev. 1c april 2004 functional description the ml6428 is a dual monolithic continuous time video ?ter designed for reconstructing the luminance and chrominance signals from an s-video d/a source. composite video output is generated by summing the y and c outputs. the ml6428cs-1 is intended for use in ac coupled input and output applications. the ml6428cs-2 is intended for ac coupled input and dc coupled output applications (see figures 5 and 6). the ?ters have a 4th-order butterworth characteristic with an optimization toward low overshoot and ?t group delay. all outputs are capable of driving 2vp-p into 150 ? video loads, with up to 35pf of load capacitance at the output pin. ml6428cs-1 outputs are ac coupled, ml6428cs-2 outputs are dc coupled. the cv output can drive two video loads plus a high-impedance modulator. thus the cv output is intended to simultaneously drive a vcr, a tv, and a high- impedance modulator. y and c are capable of driving a 75 ? load at 1vp-p. the ml6428 is capable of driving two com- posite loads and a tv modulator simultaneously. all channels are clamped during sync to establish the appro- priate output voltage swing range. thus the input coupling capacitors do not behave according to the conventional rc time constant. clamping for all channels settles within 2ms of a change in video input sources. in most applications, the ml6428's input coupling capacitors are 0.1?. the y input sinks 1.6? during active video, which nominally tilts a horizontal line by 2mv (max) at the y output (figure 4). during sync, the clamp typically sources 20? to restore the dc level. the net result is that the average input current is zero. any change in the input coupling capacitor's value will inversely alter the amount of tilt per line. such a change will also linearly affect the clamp response times. the c channel has no pulldown current sources and is essen- tially tilt-free. its input is clamped by a feedback amp which responds to the cv output. since cv = y+c, the cv output will droop by the same amount as y during active video, and will rise by the same amount as y during sync. the ml6428 is robust and stable under all stated load and input conditions. capacitavely bypassing both vcc pins directly to ground ensures this performance. (see figures 5 and 6) luminance (y) i/o the luma input is driven by either a low impedance source of 1vp-p or the output of a 75 ? terminated line. the input is required to be ac coupled via a 0.1uf coupling capacitor which allows for a nominal settling time of 2ms. the luma output is capable of driving a 150 ? load at 2vp-p or 1vp-p into a 75 ? load. ml6428cs-1 outputs are ac coupled, ml6428cs-2 outputs are dc coupled.up to 35pf of load capacitance (at the output pin) can be driven without stability or slew issues. a 220? ac coupling capacitor is recom- mended at the output (ml6428-1 only). chrominance (c) i/o the chroma input is driven by a low impedance source of 0.7vp-p or the output of a 75 ? terminated line. the input is required to be ac coupled via a 0.1uf coupling capacitor which allows for a nominal clamping time of 1ms. the chroma output is capable of driving a 150 ? load at 2vp-p or 1vp-p into a 75 ? load. ml6428cs-1 outputs are ac coupled, ml6428cs-2 outputs are dc coupled. up to 35pf of load capacitance can be driven without stability or slew issues. a 220? ac coupling capacitor is recommended at the output (ml6428-1 only). composite video (cv) output the composite video output is capable of driving 2 cv loads to 2vp-p and a high input impedance cv modulator. ml6428cs-1 outputs are ac coupled, ml6428cs-2 outputs are dc coupled. it is intended to drive three devices: tv, vcr, and a modulator. the tv or vcr input can be shorted to ground and the other outputs will still meet speci?ations. up to 35pf of load capacitance (at the output pin) can be driven without stability or slew issues. using the ml6428 for pal applications the ml6428 can be optimized for pal video by adding frequency peaking to the composite and s-video outputs. figures 7 and 8 illustrate the use of a additional external capacitor, 330pf, added in parallel to the output source termination resistor. this raises the frequency response from 1.6 db down at 4.8mhz to 0.35db down at 4.8mhz allowing for accurate reproduction of the upper sideband of the pal subcarrier. figure 9 shows the frequency response of pal video with various values of peaking capacitors (0pf, 220pf, 270pf, 330pf) between 0 and 10mhz. f or ntsc applications without the peaking capacitor the rejection at 27mhz is 42db (typical) while for pal applica- tions with the peaking capacitor the rejection at 27mhz is 38db (typical). this is shown in figure 10. the differential group delay is shown in figure 11 with and without a peak- ing capacitor (0pf, 220pf, 270pf, and 330pf) varies slightly with capacitance, going from 8ns to 13ns.
data sheet ml6428 rev. 1c april 2004 5 figure 1. passband flatness all outputs. (normalized) passband is ripple-free. figure 2. passband/stopband rejection ratios all outputs. (normalized) 1 0 ? ? ? ? amplitude (db) frequency (mhz) 0 0.1 1 10 20 0 ?0 ?0 ?0 ?0 amplitude (db) frequency (mhz) 0.01 0.1 1 100 10 figure 3. group delay, all outputs low frequency group delay is 62ns. at 3.58mhz group delay increases by only 4ns. at 4.43mhz group delay increases by only 7ns. the maximum deviation from flat group delay of 12ns occurs at 6mhz. figure 4. dc restore performance of luma output luma ramp test pattern is shown to have minimal tilt during vertical sync. in most applications, the ml6428's input coupling capacitors are 0.1?. the y input sinks 1.6? during active video, which tilts a horizontal line by 2mv at the y output 90 70 50 30 10 159 11 37 4810 26 delay (ns) frequency (mhz) scale: 200ms/div scale: 200ms/div region of tilt
ml6428 data sheet 6 rev. 1c april 2004 t ypical applications figure 5. ac coupled s-video and composite video line driver for ntsc (note: ml6428-1 outputs must be ac coupled) figure 6. dc coupled s-video and composite video line driver for ntsc (note: ml6428-2 outputs must be dc coupled) 220 f 220 f 1 f 0.1 f 220 f 0.1 f 0.1 f 220 f video cables 75 ? 75 ? 75 ? c* r* 75 ? 75 ? 75 ? 75 ? 75 ? ml6428-1 y out cvout cvout on-channel modulator, vcr, and tv cout yin cin 5v + + 4th-order filter 4th-order filter 1 4 8 5 3 7 2 6 * c and r depend on the input impedance of load 1 f 0.1 f 0.1 f 0.1 f video cables 75 ? 75 ? 75 ? 75 ? 75 ? 75 ? 75 ? 75 ? ml6428-2 y out cvout cvout on-channel modulator, vcr, and tv cout yin cin 5v + + 4th-order filter 4th-order filter 1 4 8 5 3 7 2 6 c* r* * c and r depend on the input impedance of load
data sheet ml6428 rev. 1c april 2004 7 t ypical applications figure 7. ac coupled s-video and composite video line driver for pal (note: ml6428-1 outputs must be ac coupled) figure 8. dc coupled s-video and composite video line driver for pal (note: ml6428-2 outputs must be dc coupled) 220 f 220 f 1 f 0.1 f 220 f 0.1 f 0.1 f 220 f video cables 75 ? 75 ? 75 ? c1* r* 75 ? 75 ? 75 ? 75 ? 75 ? ml6428-1 y out cvout cvout on-channel modulator, vcr, and tv cout yin cin 5v + + 4th-order filter 4th-order filter 1 4 8 5 3 7 2 6 * c1, c2, and r depend on the input impedance of load 330pf 330pf 330pf c2* 330pf 1 f 0.1 f 0.1 f 0.1 f video cables 75 ? 75 ? 75 ? 75 ? 75 ? 75 ? 75 ? 75 ? ml6428-2 y out cvout cvout on-channel modulator, vcr, and tv cout yin cin 5v + + 4th-order filter 4th-order filter 1 4 8 5 3 7 2 6 c1* r* * c1, c2, and r depend on the input impedance of load 330pf 330pf 330pf c2* 330pf
ml6428 data sheet 8 rev. 1c april 2004 figure 9. ntsc/pal video frequency response with and without peaking capacitor figure 10. stopband rejection at 27mhz with and without peaking capacitor figure 11. group delay at 5.5mhz (pal) with and without peaking capacitor ?.5 0 0.5 1 1.5 2 2.5 amplitude (db) frequency (mhz) 0468 2 157 3 0.35db with peaking 1.7db without peaking 330pf 270pf 220pf 0pf 0 10 20 30 40 50 amplitude (db) frequency (mhz) 0121830 24 6 3152127 9 ntsc/pal ?2db without peaking ntsc/pal ?8db with peaking 330pf 270pf 220pf 0pf frequency (mhz) 10 0 ?0 ?0 delay (ns) 04610 8 2 1579 3 8ns group delay without peaking 13ns group delay with 330pf peaking 330pf 270pf 220pf 0pf
data sheet ml6428 rev. 1c april 2004 9 mechanical dimensions inches (millimeters) seating plane 0.148 - 0.158 (3.76 - 4.01) pin 1 id 0.228 - 0.244 (5.79 - 6.20) 0.189 - 0.199 (4.80 - 5.06) 0.012 - 0.020 (0.30 - 0.51) 0.050 bsc (1.27 bsc) 0.015 - 0.035 (0.38 - 0.89) 0.059 - 0.069 (1.49 - 1.75) 0.004 - 0.010 (0.10 - 0.26) 0.055 - 0.061 (1.40 - 1.55) 8 0.006 - 0.01 0 (0.15 - 0.26) 0 - 8 1 0.017 - 0.027 (0.43 - 0.69) (4 places) package: s08 8-pin soic
ml6428 data sheet ?2004 fairchild semiconductor corporation life support policy fairchild? products are not authorized for use as critical components in life support devices or systems without the express written approval of the president of fairchild semiconductor corporation. as used herein: 1. life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user. 2. a critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. www.fairchildsemi.com disclaimer fairchild semiconductor reserves the right to make changes without further notice to any products herein to improve reliability, function or design. fairchild does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights, nor the rights of others. ordering information model part number lead free package container pack quantity ml6428 ml6428cs1 soic-8 rail 95 ml6428 ml6428cs1x soic-8 reel 2500 ml6428 ml6428cs1x_nl soic-8 reel 2500 ml6428 ml6428cs2 soic-8 rail 95 ml6428 ml6428cs2x soic-8 reel 2500 t emperature range for all parts: -40? to +85?
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