clamp cap clamp gate input ground +vcc video output n/c clamp input (-) clamp input (+) ground 4707 dey road liverpool, n.y. 13088 m.s.kennedy corp. (315) 701-6751 features: 230 mhz video bandwidth with vout=4vpp transition times less than 2.0ns with vout=4vpp 0 to 4 volt high input impedance dc drive control with 3db range 0 to 4 volt high input impedance dc contrast control with 40db range externally gated comparator for brightness control simple to parallel for rgb color tracking 0.5v to 9.0v output voltage swing capability on board accurate reference voltage generator available fully qualified to mil-prf-38534 wide bandwidth video amplifier system mil-prf-38534 certified 620 1 2 3 4 5 6 7 8 9 control output (+) attn. input (+) attn. input (-) control output (-) ground video input contrast control input drive control input vref output pin-out information 10 11 12 13 14 15 16 17 18 wideband amplifier with gain and dc offset control high resolution crt monitor ultra high performance video processing typical applications equivalent schematic the msk 620(b) is a very high frequency video amplifier system capable of driving displays with resolutions up to 1664 x 1200. brightness is controlled with a gated differential input black level clamp comparator. there are also dc inputs available for contrast control and drive control. all dc control inputs operate over a 0v to 4v input range and feature high impedance inputs. the msk 620(b) is packaged in a space efficient hermetically sealed 18 pin dip package. description: rev. a 8/00 1 iso 9001 certified by dscc
r load = v in =n/c comparator off comparator on clamp cap voltage = 0v clamp cap voltage = 6v v contrast =0.5v f in =12khz v drive =0v to 4v v 0 =4v pp v 0 =4v pp v 0 =4v pp i l =0ma ext v cc =11v to 13v i l =0 to 10ma -55c tc 125c static power supply current video input bias voltage clamp gate high input voltage clamp gate low input voltage dynamic characteristics video amplifier gain video output low voltage video output high voltage attenuation video amplifier input resistance gain range -3db video amplifier bandwidth output rise time output fall time voltage reference output voltage line regulation load regulation output voltage change w/temp. +13.5v 19.0c/w vcc 3 vin 3 gnd 28.0ma 20ma 1 2 3 4 5 6 -65c to +150c 300c -40c to +85c -55c to +125c 150c absolute maximum ratings t st t ld t c t j storage temperature range lead temperature range (10 seconds) case operating temperature MSK620 MSK620b junction temperature supply voltage thermal resistance (junction to case) voltage at any input pin video output current reference output current +v cc q jc v in i out i outref r in =30 w , c in =10f, r l =499 w , unless otherwise specified. clamp gate input=0v, v contrast =v drive =v brightness =4v. guaranteed by design but not tested. typical parameters are representative of actual device performance but are for reference only. industrial grade devices shall be tested to subgroups 1 and 4 unless otherwise specified. military grade devices ('b' suffix) shall be 100% tested to subgroups 1,2,3 and 4. subgroup 5 and 6 testing available upon request. subgroup 1,4 t a =t c =+25c subgroup 2,5 t a =t c =+125c subgroup 3,6 t a =t c =-55c notes: typ. 60 2.65 - - 20 0.2 10 -23 20 6 230 1.5 1.5 5.00 0.006 0.005 0.18 min. - 2.0 2.0 - 16 - 9.0 - - 5 200 - - 4.95 - - - max. 68 2.9 - 0.8 24 0.65 - - - - - 2.0 2.0 5.05 0.01 0.01 0.45 min. - 2.0 1.8 - 16 - 9.0 - - 5 190 - - 4.9 - - - max. 72 2.9 - 1.0 24 0.65 - - - - - 3.0 3.0 5.1 0.01 0.01 0.45 msk 620b msk 620 parameter test conditions electrical specifications +vcc=+12.0v unless otherwise specified 1 ma v v v v/v v v db k w db mhz ns ns v %/v %/ma % units 2 5 5 2 5 5 typ. 60 2.65 - - 20 0.2 10 -23 20 6 200 2.0 2.0 5.0 0.006 0.005 0.18 2 2 2 5 5 5 group a subgroup 1,2,3 1,2,3 1,2,3 1,2,3 4 4 4 - - 4 4 4 4 1 - - - rev. a 8/00 2
application notes pin 6 is the video input pin. the video input signal is coupled to this point through a 30 w , 10f 'rc' filter as shown in figure two. the msk 620 is designed to receive input voltages as high as 13.5v. video input pin 16 is the (-) clamp input pin. this pin is the inverting input to the clamp comparator. a 10k w feedback resistor is connected from this pin to the output pin of the amplifier (pin 14). when the clamp comparator is enabled, the voltage at pin 16 is compared to the voltage at pin 17, which is the non- inverting input of the clamp comparator. a source or sink cur- rent is generated at pin 10 to charge or discharge the clamp cap and supply dc bias to the video amplifier. the dc voltage at pin 17 is user adjustable through a 100k w potentiometer voltage divider to vref (see figure 2). in dc coupled cathode drive applications, brightness can be varied by varying the dc voltage at pin 17. clamp connections pin 11 is the clamp gate input pin and is driven by a ttl back porch clamp signal. a voltage level of +1.3v or less is a "low level" and a voltage level of +1.5v or greater is a "high level". an active low level at this pin enables the clamp comparator section so that dc restoration can be accomplished. this pin should be held at a "high" logic level when a back porch clamp signal is not used. dc restoration pins 15 is a no connect pin and should be tied to the nearest available video ground plane. no connect pins a typical single video channel connection diagram for the msk 620 is shown in figure 1 above. the dc voltage at pin 6 is internally fixed at +2.6v and the video signal is ac coupled to the input. an internal reference voltage generator supplies a +5.0vdc level at pin 9 for use with the contrast, drive and brightness control potentiometers. with pin 7 at 0v, minimum gain is realized. with pin 7 at 4v, maximum gain is realized. the clamp gate input at pin 11 accepts a ttl level clamp signal for dc restoration during the back porch segment of the video signal. pin 17 is the brightness control input pin and accepts a zero to four volt dc level. this level sets the black level of the signal. if pin 17=+1vdc the signal black level will be +1vdc. the 499 w load resistor biases the class a output stage and should be included during the power dissipation calculation stage. 499 w is the minimum recommended value of load resistance for the msk 620. pin 10 is the clamp comparator output pin. a capacitance of approximately 0.1f is connected from this pin to ground. dur- ing the "back porch" portion of the clamp signal, the clamp capacitor is either charged or discharged to match the voltage set on the non-inverting input of the clamp comparator (pin 16). during the video portion of the input signal, the clamp comparator is disabled and the clamp cap holds the proper dc bias in the video amplifier. clamp cap output pin 14 is the video output pin. since the output of the msk 620 is a push pull design, there is no need for an external pullup resistor. a 499 w load resistor to analog ground will optimize the output stage current level and bandwidth and is highly recommended. power supply connections pin 13 is the positive power supply pin. convenient internal power supply decoupling consists of a parallel combination of three capacitors ranging from 0.01f to 0.47f. the user is advised to connect at least a 4.7f tantalum decoupling ca- pacitor as close to the power supply pin as possible. vref output pin 9 is the vref output pin. this pin connects to the output of an ultra stable 5.0vdc reference voltage generator internal to the msk 620. this reference is used as a voltage source for the contrast, drive and clamp inputs. pin 8 is the drive control input. this pin accepts a dc voltage to control overall gain. pin 8 is internally decoupled to ground with a 0.1uf capacitor. with 0v at pin 8, the gain is minimum (-6db). with 4v at pin 8, the gain is maximum (0db). drive control is approximated by the following formula: attenuation (db) = (1.5) x (drive voltage) - (6db) see graph of attenuation vs. drive control voltage. drive control contrast control to achieve contrast control, pin 1 is shorted to pin 2 and pin 3 is shorted to pin 4. the voltages at pins 1 and 4 are con- trolled by the input voltage at pin seven. as the voltage at pin 7 increases, the voltages at pins 1 and 4 become offset. with pin 7 at zero volts, pins 1 and 4 are at minimum offset and the contrast is set to the minimum value of -38db typical. with pin 7 at 4v, pins 1 and 4 are at maximum offset and contrast is maximized to +26db. pin 7 is internally decoupled to ground with a 0.1uf capacitor. rev. a 8/00 3
typical performance curves rev. a 8/00 4
complete rgb video system a typical connection diagram for a red, green, blue video amplifier system is shown in figure 2. to achieve optimum contr ast tracking, a master slave contrast connection is utilized. this is accomplished by connecting pins 1 and 2 of all three preampl ifiers together and using the contrast control of one channel to vary the contrast of all three channels simultaneously. white balanc e is achieved through individual drive controls. black level can also be adjusted for each channel by adjusting the voltage at pin 17. if the cathode is ac coupled, the video signal is dc restored at the cathode. in that case black level clamping can be accomplish ed by biasing pin 17 to the desired black level. the video output pins of the msk 620 rests at approximately +3.9vdc and the inpu t of the msk 640 must be biased at approximately +1.55vdc. d1, d2, d3 and q1 act as a level shifting stage to match the dc level requirements of the preamplifier and the driver. black level control is accomplished with r8 and r9 sampling the output and feeding it back to the clamping section of the msk 620. this scheme provides black level control superior to locally sampling the msk 620 output and feeding that back to the clamping section. rev. a 8/00 5
ordering information screening level MSK620 industrial the information contained herein is believed to be accurate at the time of printing. msk reserves the right to make changes to its products or specifications without notice, however, and assumes no liability for the use of its products. mechanical specifications m.s. kennedy corp. 4707 dey road, liverpool, new york 13088 phone (315) 701-6751 fax (315) 701-6752 www.mskennedy.com MSK620b military-mil-prf-38534 all dimensions are 0.010 inches unless otherwise labeled note: esd triangle indicates pin 1. part number rev. a 8/00 6
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