device description the zxfv202 is a single high speed amplifier designed for video and other high speed applications. packaged in a small sot23-5 it is ideally suited to applications where space is at a premium. in applications where cross talk is critical this part provides better isolation than dual or quad devices. it features low differential gain and phase performance. high output drive capability compliments this part for use in video applications. features and benefits ? unity gain bandwidth 300mhz ? slew rate 400v/ s ? differential gain 0.01% ? differential phase 0.01 ? output current 40ma ? characterised up to 400pf load ? 5 volt supply ? supply current 7ma ? packaged in sot23-5 or 8 pin so applications ? video gain stages ? cctv buffer ? video distribution ? rgb buffering ? xdsl ? home theatre ? fast adc signal input drive ? high frequency instrumentation ? cable driving ? radar imaging ? medical imaging ordering information zxfv202 issue 2 - june 2002 1 video ampliifier part number container increment ZXFV202E5ta reel 7? 3000 ZXFV202E5tc reel 13? 10000 sot23-5 package part number container increment zxfv202n8ta reel 7? 500 zxfv202n8tc reel 13? 2500 so8 package
absolute maximum ratings supply voltage 11v inputs to ground* v+ -0.5v to v- -0.5v operating ambient temperature range -40c to 85c storage -65c to 150c operating temperature range t jmax ** 150c **the thermal resistance from the semiconductor die to ambient is typically 195c/w when the sot23-5 package is mounted on a pcb in free air. the power dissipation of the device when loaded must be designed to keep the device junction temperature below t jmax . similarly, the so8 package thermal resistance is typically 168c/w. *during power-up and power-down, these voltage ratings require an appropriate sequence of applying and removing signals and power supplies. esd: this device is sensitive to static discharge and proper handling precautions are required. zxfv202 issue 2 - june 2002 2 parameter conditions test min. typ. max. units supply voltage v+ operating range 4.75 5 5.25 v supply voltage v- operating range -5.25 -5 -4.75 v supply current p 5 7 9 ma input common mode voltage range p 3v input offset voltage p 1 10 mv output offset voltage p 2 20 mv input bias current, non inverting input p510 a input resistance p 1.5 2 6.5 m open loop gain p 48 61 db output voltage swing p 3v output drive current p 40 ma positive psrr p 49 57 db negative psrr p 51 58 db bandwidth av = +1, v out =200mv pk-pk c 300 mhz slew rate av = +1, v out =2v pk-pk av=+2,v out =2v pk-pk av = +10, v out =2v pk-pk c c c 400 400 400 v/ s rise time v out = 61 v, 10% - 90% c 4.0 ns fall time v out = 1v, 10% - 90% c 3.2 ns propagation delay v out = 2 v, 50% c 4 ns differential gain 3.6mhz (ntsc) & 4.4mhz (pal) c 0.01 % differential phase 3.6mhz (ntsc) & 4.4mhz (pal) c 0.01 deg electrical characteristics test conditions: v cc = 5v, t amb =25 c unless otherwise stated. rf =1k , r l = 150 ,c l <= 10pf
zxfv202 issue 2 - june 2002 3 figure 1: typical video signal application circuit, gain = 2(overall gain = 1 for 75 load) figure 2: pulse response, unity gain, 1v pk-pk, r f = 510
applications information introduction a typical circuit application is shown in figure 1, above. this is suitable for 75 transmission line connections at both the input and the output and is useful for distribution of wide-band signals such as video and xdsl via cables. the 75 reverse terminating resistor r4 gives the correct matching condition to a terminated video cable. the amplifier load is then 150 in parallel with the local feedback network. the wide bandwidth of this device necessitates some care in the layout of the printed circuit. partly for this reason, an evaluation circuit board is available and is described in a later paragraph. a continuous ground plane is required under the device and its signal connection paths, to provide the shortest possible ground return paths for signals and power supply filtering. a double-sided or multi-layer pcb construction is required, with plated-through via holes providing closely spaced low-inductance connections from some components to the continuous ground plane (some of these holes are not visible in the figures for the evaluation circuit board ? artworks and nc drill output can be provided if required). for the power supply filtering, low inductance surface mount capacitors are normally required. it has been found that very good rf decoupling is provided on each supply using a 1000pf npo size 0805 or smaller ceramic surface mount capacitor, closest to the device pin, with an adjacent 0.1 f x7r capacitor. other configurations are possible and it may be found that a single 0.01uf x7r capacitor on each supply gives good results. however this should be supported by larger decoupling capacitors elsewhere on the printed circuit board. values of 1 to 10 f are recommended, particularly where the voltage regulators are located more than a few inches from the device. these larger capacitors are recommended to be solid tantalum electrolytic or ceramic types. note particularly that the inverting input of this current feedback type of amplifier is sensitive to small amounts of capacitance to ground which occur as part of the practical circuit board layout. this capacitance affects bandwidth, frequency response peaking and pulse overshoot. therefore to minimise this capacitance, the feedback components r2 and r3 of figure1 should be positioned as close as possible to the inverting input connection. the frequency response and pulse response will vary according to particular values of resistors and layout capacitance. the response can be tailored for the application to some extent by choice of the value of feedback resistor. figure 2 shows an oscilloscope display of the pulse response of the evaluation circuit described below for rf = 510 . customer evaluation circuit figures 4 and 5 show the schematic and copper layout of a double-sided printed circuit board suitable for evaluation of the device in the laboratory. a parts list is provided below. this layout serves as a useful example for many applications, showing the practical implementation of the advice given above in the introduction. bnc connector sockets allow connection to test instruments via 50 cables. the output circuit includes a resistor matching circuit to present a load of 150 ohms to the amplifier and simultaneously provide 50 ohms output impedance. the attenuation of this matching circuit is 15.45 db. as the amplifier is configured for a voltage gain of 2, the overall gain is: 6 - 15.45 = -9.45db. evaluation circuit parts list: zxfv202 issue 2 - june 2002 4 qty cct-ref value description resistors, surface mount 1 r1, 51r 0805 2 r2,r3 1k 0805 1 r4 120r 0805 1 r5 10r 0805 1 r6 62r 0805 capacitors, surface mount 2 c1,c2 1nf 25v ceramic 0805 x7r 2 c3,c4 100nf 50v ceramic 0805 npo 2 c5,c6 10 f 16v tant elec size c integrated circuits 1u1 zetex zxfv202n8 miscellaneous 2 j1,j2 bnc socket, pcb straight flange, e.g. tyco b35n14h999x99 1j3 3-way pcb screw terminal block imo 20.501/3sb
zxfv202 issue 2 - june 2002 5 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 -0.04 -0.03 -0.02 -0.01 0.00 0.01 0.02 0.03 0.04 gain phase typical differential gain & phase vs d.c offset. pal, 4.43mhz gain (%), phase () dc bias (v) -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 -0.04 -0.03 -0.02 -0.01 0.00 0.01 0.02 0.03 0.04 gain phase typical differential gain & phase vs d.c offset ntsc, 3.58mhz ) gain (%), phase () dc bias (v) figure 3: evaluation circuit schematic
zxfv202 issue 2 - june 2002 6 figure 4 evaluation circuit top copper layout (overall dimensions 2.5 x 2.25 inches) figure 5: evaluation board bottom copper layout (viewed through from top)
zxfv202 issue 2 - june 2002 europe zetex plc fields new road chadderton oldham, ol9 8np united kingdom telephone (44) 161 622 4422 fax: (44) 161 622 4420 uksales@zetex.com zetex gmbh streitfeldstra?e 19 d-81673 mnchen germany telefon: (49) 89 45 49 49 0 fax: (49) 89 45 49 49 49 europe.sales@zetex.com americas zetex inc 700 veterans memorial hwy hauppauge, ny11788 usa telephone: (631) 360 2222 fax: (631) 360 8222 usa.sales@zetex.com asia pacific zetex (asia) ltd 3701-04 metroplaza, tower 1 hing fong road kwai fong hong kong telephone: (852) 26100 611 fax: (852) 24250 494 asia.sales@zetex.com these offices are supported by agents and distributors in major countries world-wide. this publication is issued to provide outline information only which (unless agreed by the company in writing) may not be used, applied or reproduced for any purpose or form part of any order or contract or be regarded as a representation relating to the products or services concerned. the company reserves the right to alter without notice the specification, design, price or conditions of supply of a ny product or service. for the latest product information, log on to www.zetex.com ? zetex plc 2002 7 sot23-5 package information dim inches dim inches min max min max a 0.053 0.069 e 0.050 bsc a1 0.004 0.010 b 0.013 0.020 d 0.189 0.197 c 0.008 0.010 h 0.228 0.244 08 88 e 0.150 0.157 h 0.010 0.020 l 0.016 0.050 so8 package dimensions so8 package outline dim millimetres dim millimetres min max min max a 0.90 1.45 e 2.20 3.20 a1 0.00 0.15 e1 1.30 1.80 a2 0.90 1.3 e 0.95 ref b 0.20 0.50 e1 1.90 ref c 0.09 0.26 l 0.10 0.60 d 2.70 3.10 a 0 30 sot23-5 package dimensions
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