general description the max5491 precision resistor-divider consists of twoaccurately matched resistors with access to the ends and center of the divider. this device offers excellent resistance matching of 0.035% (a grade), 0.05% (b grade), and 0.1% (c grade). the max5491 includes an extremely low resistance-ratio temperature drift of 2ppm/? over -40? to +85?, and has an end-to-end resistance of 30k ? . resistance ratios from 1:1 to 30:1 are available. ten standard ratios are available (see table1), and custom ratios are also available upon request. to enhance device and system robustness, the max5491 also features ?kv human body model electrostatic dis- charge (esd) protection to ensure against real-world esd events. the max5491 is ideal for precision gain-set- ting applications where tight resistance matching and low temperature drift are necessary. the max5491 is available in a space-saving 3-pin sot23 package, and is guaranteed over the extended -40? to +85? temperature range. applications industrial process controlinstrumentation precision gain setting medical equipment automatic test equipment base stations features ? resistance ratios from 1:1 to 30:1 ? custom ratios available upon request ? 2kv human body model esd protection ? tight initial ratio accuracy 0.035% (max5491a)0.05% (max5491b) 0.1% (max5491c) ? low 2ppm/ c resistor-ratio-drift ? up to 50v operating voltage across sum of r1and r2 ? tiny 3-pin sot23 package max5491 precision-matched resistor-divider in sot23 ________________________________________________________________ maxim integrated products 1 p2 1 3 p3 p1 max5491 sot23 top view 2 pin configuration ordering information* p1p2 p3 max5491 r 2 r 1 block diagram 19-3009; rev 3; 12/04 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. * see the how to order section for more details. pa r t t em p r a n g e pin - pa c k a g e ra tio ac cur acy (%) max5491 _ a _ _ _ _ _ -t -40? to +85? 3 sot23-3 0.035 max5491 _ b _ _ _ _ _ -t -40? to +85? 3 sot23-3 0.05 max5491 _ c _ _ _ _ _ -t -40? to +85? 3 sot23-3 0.1 downloaded from: http:///
max5491 precision-matched resistor-divider in sot23 2 _______________________________________________________________________________________ absolute maximum ratings dc electrical characteristics(t a = -40? to +85?, unless otherwise noted. typical values 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 ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. voltage between p1 and p2...................................................50v continuous current into any pin....................................?.75ma continuous power dissipation (t a = +70?) 3-pin sot23 (derate 7.1mw/? above +70?).........571.4mw operating temperature range ...........................-40? to +85? junction temperature ......................................................+150? storage temperature range .............................-65? to +150? lead temperature (soldering, 10s) .................................+300? parameter symbol conditions min typ max units max5491_a, t a = +25? ?.035 max5491_b, t a = +25? ?.05 initial resistor ratio error (note 2) max5491_c, t a = +25? ?.1 % 1:1 ratio 3.2:1 2 3.2:1 < ratio 10:1 4 resistance-ratio temperaturecoefficient (note 3) 10:1 < ratio 30:1 5.5 ppm/? absolute temperature coefficientof resistance tcr (note 4) 35 ppm/? voltage coefficient of resistance vcr (note 5) 0.1 ppm/v end-to-end resistance (r 1 + r 2 ) 28.5 30 31.5 k ? continuous current i r1 , i r2 ?.75 ma continuous working voltagebetween p1 and p2 v p1-p2 05 0 v power rating 87.5 mw pin capacitance 2p f resistance ratio long-termstability 2000hr at +70? ?.03 % note 1: the max5491 is 100% production tested at t a = +25?. specifications over -40? to +85? are guaranteed by design. note 2: testing conditions: t a = +25?, v p1-p2 = 9v and 50v. note 3: resistance-ratio temperature coefficient is defined as note 4: absolute tcr is defined as and is tested at 9v and 50v. note 5: resistance-ratio voltage coefficient is defined as ? ? r r r r t 1 2 1 2 ?? ? ?? ? ? ? r r r r v 1 2 1 2 ?? ? ?? ? ? ? rr rr t 12 12 + () + () downloaded from: http:///
max5491 precision-matched resistor-divider in sot23 _______________________________________________________________________________________ 3 normalized resistor-ratio drift vs. temperature max5491 toc01 temperature ( c) ratio drift (ppm) 75 50 -25 0 25 -300 -200 -100 0 100 200 300 400 -400 -50 100 v p1-p2 = 10v ratio = 1:1 normalized resistor-ratio drift vs. temperature max5491 toc02 temperature ( c) ratio drift (ppm) 75 50 -25 0 25 -300 -200 -100 0 100 200 300 400 -400 -50 100 v p1-p2 = 10v ratio = 5:1 typical operating characteristics (v p1-p2 = 10v, t a = +25?, unless otherwise noted.) pin description pin name function 1p 1 r 1 connection terminal 2p 2 r 2 connection terminal 3 p3 midpoint between r 1 and r 2 connection terminals detailed description as shown in the block diagram , the max5491 consists of two precision, low-ratio-drift resistors with an end-to-end resistance of 30k ? (r 1 + r 2 ). p3 is the center tap of the divider. the maximum working voltage of themax5491 is 50v. this device offers a wide range of resistance ratios (r 1 /r 2 ) from 1:1 to 30:1 and is ideally suited for precision operational amplifier gain/attenua-tion control. the max5491 features a ?kv esd protec- tion that enhances system robustness. a maximum initial ratio accuracy of 0.035% and a low 2ppm/ c ratio drift enhance system accuracy. downloaded from: http:///
max5491 applications information self-heating and error applying a voltage across terminals p1 and p2 causesthe device to heat up due to power dissipation. in high- voltage applications, consider the error in resistance- ratio temperature coefficient caused by self-heating. the worst-case self-heating occurs when the operating voltage attains its maximum value. approximate the result of power dissipation under this condition as: the thermal resistance from junction to ambient, j-a , for a 3-pin sot23 package is 141?/w. calculate theresulting temperature rise as: ? t = 83.3mw x 141?/w = 11.7? if the ratio temperature coefficient is 2ppm/? (typ), thetotal error introduced by self-heating is: 11.7 c x 2ppm/ c = 23.4ppm p v r v k mw diss max . = () = () = 22 50 30 83 3 ? precision-matched resistor-divider in sot23 4 _______________________________________________________________________________________ in p1 p2 p3 max5491 r 2 r 1 out figure 3. buffered attenuator max5491 r 2 r 1 p1 p2 p3 in out figure 1. inverting amplifier configuration p1 p2 p3 max5491 r 2 r 1 out in figure 4. attenuator with buffer max5491 r 2 r 1 p1 p2 p3 in out figure 2. noninverting amplifier configuration a v v r r out in == 1 2 a v v r r out in == + 1 1 2 a v v r rr out in == + 2 12 a v v r rr out in == + 2 12 typical applications downloaded from: http:///
example part numbers max5491 precision-matched resistor-divider in sot23 _______________________________________________________________________________________ 5 prefix max 5491 v a 10000 -t root part numbermax5491 = 30k ? end-to-end ratio rangel through w. resistor ratio must fall in the appropriate ratio range. (see table 2.) ratio accuracya = 0.035% (max); b = 0.05% (max); c = 0.1% (max) resistance ratio five number ratio designator. ratios available from 1:1 to 30:1. format examples: 010000 = 1:1 02500 = 2.5:1 07538 = 7.538:1 25000 = 25:1 tape and reel how to order part resistor-ratio range resistor-ratio accuracy (% max) resistor ratio max5491ra02500-t 2.000 to 2.899 0.035 2.5:1 max5491vc10000-t 10.000 to 15.999 0.100 10:1 max5491sb03200-t 2.900 to 3.999 0.050 3.2:1 max5491ua07538-t 6.000 to 9.999 0.035 7.538:1 table 1. standard ratios* part resistor ratio resistor-ratio suffix resistor-ratio accuracy (% max) top mark max5491la01000-t 1:1 01000 0.035 fzpd max5491lb01000-t 1:1 01000 0.050 fzpe max5491lc01000-t 1:1 01000 0.100 fzpf max5491ma01100-t 1.1:1 01100 0.035 fzpa max5491mb01100-t 1.1:1 01100 0.050 fzpb max5491mc01100-t 1.1:1 01100 0.100 fzpc max5491na01500-t 1.5:1 01500 0.035 fzox max5491nb01500-t 1.5:1 01500 0.050 fzoy MAX5491NC01500-t 1.5:1 01500 0.100 fzoz max5491pa02000-t 2:1 02000 0.035 fzoo max5491pb02000-t 2:1 02000 0.050 fzop max5491pc02000-t 2:1 02000 0.100 fzoq max5491ra02500-t 2.5:1 02500 0.035 fzpp downloaded from: http:///
max5491 precision-matched resistor-divider in sot23 6 _______________________________________________________________________________________ table 1. standard ratios* (continued) part resistor ratio resistor-ratio suffix resistor-ratio accuracy (% max) top mark max5491rb02500-t 2.5:1 02500 0.050 fzpq max5491rc02500-t 2.5:1 02500 0.100 fzon max5491sa03200-t 3.2:1 03200 0.035 fzou max5491sb03200-t 3.2:1 03200 0.050 fzov max5491sc03200-t 3.2:1 03200 0.100 fzow max5491ta05000-t 5:1 05000 0.035 fzor max5491tb05000-t 5:1 05000 0.050 fzos max5491tc05000-t 5:1 05000 0.100 fzot max5491ua07538-t 7.538:1 07538 0.035 fzpm max5491ub07538-t 7.538:1 07538 0.050 fzpn max5491uc07538-t 7.538:1 07538 0.100 fzpo max5491va10000-t 10:1 10000 0.035 fzpj max5491vb10000-t 10:1 10000 0.050 fzpk max5491vc10000-t 10:1 10000 0.100 fzpl max5491wa30000-t 30:1 30000 0.035 fzpg max5491wb30000-t 30:1 30000 0.050 fzph max5491wc30000-t 30:1 30000 0.100 fzpi * standard ratios are available for ordering in any quantity. nonstandard ratios are also available for values between 1:1 to 30: 1. a minimum order quantity of 10,000 units is required for nonstandard ratios. please contact factory for more information. table 2. ratio ranges letter suffix resistor-ratio range l 1.000 to 1.099 m 1.100 to 1.349 n 1.350 to 1.699 p 1.700 to 2.000 r 2.001 to 2.899 s 2.900 to 3.999 t 4.000 to 5.999 u 6.000 to 9.999 v 10.000 to 15.999 w 16.000 to 30.000 chip information transistor count: 0process: bicmos downloaded from: http:///
max5491 precision-matched resistor-divider in sot23 maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim product. no circuit 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 _____________________ 7 2004 maxim integrated products printed usa is a registered trademark of maxim integrated products. package information (the package drawing(s) in this data sheet may not reflect the most current specifications. for the latest package outline information, go to www.maxim-ic.com/packages .) sot23 l.eps f 1 1 21-0051 package outline, 3l sot-23 downloaded from: http:///
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