general description the lm4041 is a precision two-terminal shunt mode, bandgap voltage reference with a fixed reverse break- down voltage of 1.225v. ideal for space-critical appli- cations, the lm4041 is offered in the subminiature 3-pin sc70 surface-mount package (1.8mm ? 1.8mm), 50% smaller than comparable devices in sot23 surface- mount packages (sot23 versions are also available). laser-trimmed resistors ensure precise initial accuracy. with a 100ppm/? temperature coefficient, the device is offered in four grades of initial accuracy ranging from 0.1% to 1%. the lm4041 has a 60? to 12ma shunt current capability with low dynamic impedance, ensur- ing stable reverse breakdown voltage accuracy over a wide range of operating temperatures and currents. the lm4041 does not require an external stabilizing capacitor while ensuring stability with any capacitive load. ________________________applications portable, battery-powered equipment notebook computers cell phones industrial process controls features ultra-small 3-pin sc70 package 0.1% max initial accuracy 100ppm/? max temperature coefficient guaranteed over -40? to +85? temperature range wide operating current range: 60? to 12ma low 20? rms output noise (10hz to 10khz) 1.225v fixed reverse breakdown voltage no output capacitors required tolerates capacitive loads lm4041 improved precision micropower shunt voltage reference ________________________________________________________________ maxim integrated products 1 - 1 3 n.c.* + lm4041 sc70-3/sot23-3 top view 2 *pin 3 must be left floating or connected to pin 2. part output voltage (v) initial accuracy (%) tempco (ppm/ c) lm4041aim3-1.2 1.225 0.1 100 lm4041aix3-1.2 1.225 0.1 100 lm4041bim3-1.2 1.225 0.2 100 lm4041bix3-1.2 1.225 0.2 100 lm4041cim3-1.2 1.225 0.5 100 lm4041cix3-1.2 1.225 0.5 100 lm4041dim3-1.2 1.225 1.0 150 lm4041dix3-1.2 1.225 1.0 150 pin configuration selector guide 19-1704; rev 0; 4/00 for free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800. for small orders, phone 1-800-835-8769. ordering information part* temp. range pin- package top mark lm4041aix3-1.2 -40 c to +85 c 3 sc70-3 abf lm4041aim3-1.2 -40 c to +85 c 3 sot23-3 fzeb lm4041bix3-1.2 -40 c to +85 c 3 sc70-3 abg lm4041bim3-1.2 -40 c to +85 c 3 sot23-3 fzec lm4041cix3-1.2 -40 c to +85 c 3 sc70-3 abh lm4041cim3-1.2 -40 c to +85 c 3 sot23-3 fzed lm4041dix3-1.2 -40 c to +85 c 3 sc70-3 abi lm4041dim3-1.2 -40 c to +85 c 3 sot23-3 fzee *see selector guide for a listing of lm4041 output voltage, initial accuracy, and temperature coefficient specifications.
lm4041 improved precision micropower shunt voltage reference 2 _______________________________________________________________________________________ absolute maximum ratings electrical characteristics (i r = 100a, t a = t min to t max , unless otherwise noted. typical values are at t a = +25 c.) (note 1) stresses beyond those listed under ?bsolute maximum ratings?may cause permanent damage to the device. these are stress rating s only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specificatio ns is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. note 1: all devices are 100% production tested at +25 c and are guaranteed by design for t a = t min to t max , as specified. note 2: the overtemperature limit for reverse breakdown voltage tolerance is defined as the room-temperature reverse breakdown voltage tolerance [( ? v r / ? t)(max ? t)(v r )], where ? v r / ? t is the v r temperature coefficient, max ? t is the maximum difference in temperature from the reference point of +25 c to t min or t max , and v r is the reverse breakdown voltage. the total overtemperature tolerance for the different grades in the temperature range where max ? t = +65 c is shown below: a grade: 0.75% = 0.1% 100 ppm/ c ? 65 c b grade: 0.85% = 0.2% 100 ppm/ c ? 65 c c grade: 1.15% = 0.5% 100 ppm/ c ? 65 c d grade: 1.98% = 1.0% 150 ppm/ c ? 65 c note 3: guaranteed by design. reverse current (cathode to anode) ..................................20ma forward current (anode to cathode) ..................................10ma esd per method 3015.7 human body model .......................................................2000v machine model.................................................................200v continuous power dissipation (t a = +70 c) 3-pin sc70 (derate 2.17mw/ c above +70 c) ............174mw 3-pin sot23 (derate 4.01mw/ c above +70 c)..........320mw operating temperature range ..........................-40 c to +85 c storage temperature range .............................-65 c to +150 c junction temperature ......................................................+150 c lead temperature (soldering, 10s) ................................+300 c parameter symbol conditions min typ max units reverse breakdown voltage v r t a = +25 c 1.225 v lm4041a (0.1%) 1.2 9.2 lm4041b (0.2%) 2.4 10.4 lm4041c (0.5%) 6.0 14 reverse breakdown voltage tolerance (note 2) ? v r lm4041d (1.0%) 12 24 mv lm4041a/b/c 45 60 minimum operating current i rmin lm4041d 45 65 a i r = 10ma 20 lm4041a/b/c 15 100 i r = 1ma lm4041d 15 150 average reverse voltage temperature coefficient (note 2) ? v r / ? t i r = 100 a 15 ppm/ c lm4041a/b/c 0.7 1.5 i rmin i r 1ma lm4041d 0.7 2.0 lm4041a/b/c 2.5 8.0 reverse breakdown voltage change with operating current change ? v r / ? i r 1ma i r 12ma lm4041d 2.5 10.0 mv lm4041a/b/c 0.5 1.5 reverse dynamic impedance (note 3) z r i r = 1ma, f = 120hz, i ac = 0.1i r lm4041d 0.5 2.0 ? wideband noise e n i r = 100 a, 10hz f 10khz 20 v rms reverse breakdown voltage long-term stability ? v r t = 1000h, i r = 100 a 120 ppm
lm4041 improved precision micropower shunt voltage reference _______________________________________________________________________________________ 3 -1.0 -0.6 -0.8 -0.2 -0.4 0 0.2 -50 0 50 100 temperature drift lm4041-02 temperature (?) reference voltage change (mv) 0 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 0 5 10 15 20 reverse voltage vs. current lm4041-03 reverse current (ma) reverse voltage change (mv) 0.5 t a = -40 c t a = +25 c t a = +85 c typical operating characteristics (i r = 100a, sc70-3 package, t a = +25 c, unless otherwise noted.) 0 20 60 40 80 100 0 0.8 0.4 1.2 1.6 2.0 reverse characteristics and minimum operating current lm4041-01 reverse voltage (v) reverse current (a) v gen v r (ac-coupled) 2v/div 2mv/div load-transient response lm4041-05 10 s/div i shunt = 1ma 250 a, r l = 10k ? see figure 1 v gen v r 2v/div 2mv/div load-transient response lm4041-06 10 s/div i shunt = 10ma 2.5ma, r l = 1k ? see figure 1 v gen v r (ac-coupled) 2v/div 2mv/div load-transient response lm4041-04 10 s/div i shunt = 100 a 25 a, r l = 100k ? see figure 1 1k v b + - i shunt v r r l v gen figure 1. load-transient test circuit
lm4041 improved precision micropower shunt voltage reference 4 _______________________________________________________________________________________ 100 10k 1k 100k 1m output impedance vs. frequency lm4041-08 frequency (hz) impedance ( ? ) 1000 0.1 1 10 100 c 1 = 0 i r = c 1 = 1 f i r = 1ma 150 a 10,000 100 10 1k 10k 1000 frequency (hz) noise (nv / hz) 100 noise vs. frequency lm4041-09 i r = 200 a typical operating characteristics (continued) (i r = 100a, sc70-3 package, t a = +25 c, unless otherwise noted.) r s = 30k ? see figure 2 08 41216 startup characteristics lm4041-07 response time (s) 5v v in o 0 1.5v 1.0v v out o.5v pin description pin name function 1 + positive terminal of the shunt reference 2 ? negative terminal of the shunt reference 3 n.c. leave this pin unconnected, or connect to pin 2. r s 30k v in 1hz rate v r figure 2. startup characteristics test circuit
lm4041 improved precision micropower shunt voltage reference _______________________________________________________________________________________ 5 detailed description the lm4041 shunt references use the bandgap princi- ple to produce a stable, accurate voltage. the device behaves similarly to an ideal zener diode; a fixed volt- age of +1.225v is maintained across its output termi- nals when biased with 60a to 12ma of reverse current. the lm4041 behaves similarly to a silicon diode when biased with forward currents up 10ma. figure 3 shows a typical operating circuit. the lm4041 is ideal for providing a stable reference from a high- voltage power supply. applications information the lm4041 s internal pass transistor is used to main- tain a constant output voltage (v shunt ) by sinking the necessary amount of current across a source resistor. the source resistance (r s ) is determined from the load current (i load ) range, supply voltage (v s ) variations, v shunt , and desired quiescent current. choose the value of r s when v s is at a minimum and i load is at a maximum. maintain a minimum i shunt of 60a at all times. the r s value should be large enough to keep i shunt less than 12ma for proper regulation when v s is maximum and i load is at a minimum. to prevent damage to the device, i shunt should never exceed 20ma. therefore, the value of r s is bounded by the following equation: [v s(min) - v r ] / [60a + i load(max) ] > r s > [v s(max) - v r ] / [20ma + i load(min) ] choosing a larger resistance minimizes the total power dissipation in the circuit by reducing the shunt current (p d(total) = v s ? i shunt ). provide a safety margin to incorporate the worst-case tolerance of the resistor used. ensure that the resistor s power rating is ade- quate, using the following general power equation: p r = i shunt ? (v s(max) - v r ) output capacitance the lm4041 does not require an external capacitor for frequency stability and is stable for any output capaci- tance. temperature performance the lm4041 typically exhibits an output voltage tem- perature coefficient within 15ppm/ c. the polarity of the temperature coefficient may be different from one device to another; some may have positive coefficients, and others may have negative coefficients. figure 3. typical operating circuit lm4041 i load i shunt r s v s v r i shunt + i load chip information transistor count: 60 process: bicmos
lm4041 improved precision micropower shunt voltage reference 6 _______________________________________________________________________________________ sotpo3l.eps package information
lm4041 improved precision micropower shunt voltage reference _______________________________________________________________________________________ 7 package information (continued) sc70, 3l.eps
lm4041 improved precision micropower shunt voltage reference maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim product. no circu it patent licenses are implied. maxim reserves the right to change the circuitry and specifications without notice at any time. 8 _____________________maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 ? 2000 maxim integrated products printed usa is a registered trademark of maxim integrated products. maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim product. no circu it patent licenses are implied. maxim reserves the right to change the circuitry and specifications without notice at any time. 8 _____________________maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 ? 2000 maxim integrated products printed usa is a registered trademark of maxim integrated products. notes
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