ZXF103Q16, zxf103ev description the zxf103 is a versatile analog high q bandpass filter. it can be configured to provide pass or notch characteristics. the basic filter section requires 2 resistors and 2 capacitors to set the centre frequency. the frequency range is up to 600khz. two external resistors control filter q factor. the q can be varied up to 50. applications many filter applications including: - ? sonar and ultrasonic systems ? line frequency notch ? signalling ? motion detection ? instrumentation ? low frequency telemetry features and benefits ? centre frequency up to 1mhz ? variable q up to 50 ? low distortion ? low noise ? low power 25mw ? devices easily cascaded ? small qsop16 package zxf103 issue 2 - july 2002 variable q filter 1 r r c c r q set zxf103 filter input filter output system diagram part number package part mark ZXF103Q16 qsop16 zxf103 ordering information part number container increment ZXF103Q16ta reel 7? 178mm 500 ZXF103Q16tc reel 13? 330mm 2500 r2 0v rc2 gp1 vcc gp3 bias rc1 0v c1 fi1 gp2 nc vcc fo fi2 116 pinout
absolute maximum ratings voltage on any pin 7.0v (relative to 0v) operating temperature range 0 to 70 c storage temperature -55 to 125 c zxf103 issue 2 - july 2002 2 general characteristics parameter conditions min. typical max. units operating current 4.0 5.0 ma max. operating frequency vout=1.6v p-p vout=1.0v p-p 600 1000 khz q usable range 0.5 50 centre frequency temperature coefficient q=30, fo = 1khz 100 ppm/ c q temperature coefficient q=30, fo = 1khz 0.1 %/ c voltage noise 1 ? 100 khz 20 nv/ hz input impedance 10 15 20 k ? linear output range output load = 10 k ? 2 v pk-pk sink current 450 a source current 450 a output impedance 10 electrical characteristics test conditions: temperature =25 c, v cc = 5.00v, 0v =0.00v, r l =10k,c l =10pf pin name function 1 r2 phase retard node 2 0v 0 volts 3 rc2 phase retard node 4 bias internal bias generator 5 rc1 phase advance node 6 0v 0 volts 7 c1 phase advance node 8 fi1 filter input mode dependent 9 fi2 filter input, mode dependent 10 fo filter output for all modes 11 vcc +5 volt supply 12 n/c no connection 13 gp2 loop gain node 14 gp3 loop gain node 15 vcc +5 volt supply 16 gp1 loop gain node 11.78 11.79 11.80 11.81 11.82 number of devices frequency (khz) histogram of centre frequency (fo = 11.80khz q = 25)
zxf103 issue 2 - july 2002 3 filter configurations and responses notch filter 10k 100k 1m 10m -40 -32 -24 -16 -8 0 frequency (hz) gain (db) ac filter performance 10k 100k 1m 45 90 135 180 225 270 10m frequency (hz) phase (deg) fo 1 2rc = where r=r1=r2 and c=c1=c2 q r4 r3 where r1,r2,r3 and r4 2k ? and c1 and c2 50pf see ? designing for a value of q ? for more details.
zxf103 issue 2 - july 2002 4 filter configurations and responses (continued) inverse notch filter (with 0db stop band) 10k 100k 1m 10m 0 6 12 18 24 30 frequency (hz) gain (db) ac filter performance 10k 100k 1m 10m -270 -225 -180 -135 -90 -45 frequency (hz) fo 1 2rc = where r=r1=r2 and c=c1=c2 q r4 r3 where r1,r2,r3 and r4 2k ? and c1 and c2 50pf
zxf103 issue 2 - july 2002 5 filter configurations and responses (continued) inverse notch filter (with attenuating skirts) ac filter performance fo 1 2rc = where r=r1=r2 and c=c1=c2 q r4 r3 where r1,r2,r3 and r4 2k ? and c1 and c2 50pf see ? designing for a value of q ? for more details. the skirt ? roll off ? away from the peak is -20db/decade regardless of chosen q. typical responses from the circuit with component values derived from the diagram.
designing for a value of q as mentioned on the configuration pages, there is a proportional relationship between the ratio of r4 and r3, and q. q r4 r3 these resistors define the gain of an inverting amplifier that determines the peak value of gain and therefore the q of the filter, as q is described as; q = fo 3dbbandwidth ? this value of required gain is quite critical. as the maximum value of q is approached, too much gain will cause the filter to oscillate at the centre frequency fo. a small reduction of gain will cause the value of q to fall significantly. therefore, for high values of q factor or tight tolerances of lower values of q, the resistor ratio must be trimmed. frequency dependant effects must be accounted for in determining the appropriate gain. as the frequency increases, the effective circuit gain reduces. the required gain is nominally two but at higher frequencies it will need to be slightly greater than two in order to compensate for loss of gain and internal phase shifts. this is not really a problem for circuits where the desired fo remains constant, as the phase shifts are accounted for permanently. for designs where q is high and fo is to be ? swept ? , care must be taken that a gain appropriate at the highest frequency does not cause oscillation at the lowest. variation in q increases from device to device, as the value of q increases, due to internal gain spreads. zxf103 issue 2 - july 2002 6 6
evaluation board an evaluation board (zxf103ev) is available to assist with in-system or stand-alone performance evaluation. the board can be set, by simple jumper links, to perform any of the filter characterisitics responses. evaluation boards can be purchased from our catalogue distributors. digi-key north america www.digikey.com tel: 1-800344-4539 europe - farnell www.farnell.com tel: 44-113-263-6311 zxf103 issue 2 - july 2002 7 r2 1 0 v rc2 bias rc1 0 v c1 fi 1 gp1 vcc gp3 gp2 n/c vcc fo fi 2 zxf103 r2 6.8 k r1 6.8k r4 22 k r3 10 k vr1 2 k c4 100 nf c1 330 pf c2 330 pf c3 100 nf c6 100 nf c5 100 nf 0 v 5 v output input j1 j2 j3 evaluation board schematic notch j1 and j2 notch pass 1 j2 and j3 (0db stop band) notch pass 2 j3 only (attenuating skirts) the evaluation board is designed for operation at 70khz.
zxf103 issue 2 - july 2002 8 europe zetex plc fields new road chadderton oldham, ol9 8np united kingdom telephone (44) 161 622 4422 fax: (44) 161 622 4420 uk.sales@zetex.com zetex gmbh streitfeldstra ? e19 d-81673 m nchen 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 any product or service. for the latest product information, log on to www.zetex.com ? zetex plc 2002 qsop16 package outline conforms to jedec mo-137ab iss a dim millimetres inches min max min max a 4.80 4.98 0.189 0.196 b 0.635 0.025 nom c 0.23 ref 0.009 ref d 0.20 0.30 0.008 0.012 e 3.81 3.99 0.15 0.157 f 1.35 1.75 0.053 0.069 g 0.10 0.25 0.004 0.01 j 5.79 6.20 0.228 0.244 k0 8 0 8 qsop16 package dimensions
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