v ss out in- 15v dd in+ sot23-5/sc70-5 top view 2 34 - + MAX4490 general description the MAX4490/max4491/max4492 single/dual/quad, low-cost cmos op amps feature rail-to-rail input and output capability from either a single 2.7v to 5.5v sup- ply or dual ?.35v to ?.75v supplies. these amplifiers exhibit a high slew rate of 10v/? and a gain-bandwidth product of 10mhz. they can drive 2k ? resistive loads to within 55mv of either supply rail and remain unity- gain stable with capacitive loads up to 300pf. the MAX4490 is offered in the ultra-small, 5-pin sc70 package, which is 50% smaller than the standard 5-pin sot23 package. specifications for all parts are guaran- teed over the automotive (-40? to +125?) tempera- ture range. applications battery-powered instruments portable equipment audio signal conditioning low-power/low-voltage applications sensor amplifiers rf power amplifier control high-side/low-side current sensors features 2.7v to 5.5v single-supply operation 10v/s slew rate rail-to-rail input common-mode voltage range rail-to-rail output voltage swing 10mhz gain-bandwidth product unity-gain stable with capacitive loads up to 300pf 50pa input bias current ultra-small, 5-pin sc70 package (MAX4490) MAX4490/max4491/max4492 low-cost, high-slew-rate, rail-to-rail i/o op amps in sc70 ________________________________________________________________ maxim integrated products 1 19-1525; rev 2; 4/01 part MAX4490 axk-t MAX4490auk-t max4491 aka-t -40? to +125? -40? to +125? -40? to +125? temp range pin- package 5 sc70-5 5 sot23-5 8 sot23-5 capacitive-load stability ordering information rail-to-rail is a registered trademark of nippon motorola, ltd. max4492 aud -40? to +125? 14 tssop max4492asd -40? to +125? 14 so top mark aab adkq aadb 0 100 100k 10k 1k 2000 4000 3000 6000 1000 5000 resistive load ( ? ) capacitive load (pf) unstable stable pin configurations/ functional diagrams pin configurations continued at end of data sheet. max4491aua -40? to +125? 8 ?ax 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.
MAX4490/max4491/max4492 low-cost, high-slew-rate, rail-to-rail i/o op amps in sc70 2 _______________________________________________________________________________________ absolute maximum ratings electrical characteristics (v dd = 5v, v ss = 0, v cm = 0, v out = v dd /2, r l = 100k ? connected to v dd /2, t a = t min to t max , 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 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. supply voltage (v dd to v ss ) ....................................................6v all other pins ...................................(v ss - 0.3v) to (v dd + 0.3v) output short-circuit duration .................................................10s continuous power dissipation (t a = +70?) 5-pin sc70 (derate 2.5mw/? above +70?) ............ 200mw 5-pin sot23 (derate 7.1mw/? above +70?).......... 571mw 8-pin sot23 (derate 5.26mw/? above +70?)........421 mw 8-pin ?ax (derate 4.1mw/? above +70?) ........... 330mw 14-pin tssop (derate 8.3mw/? above +70?) ....... 667mw 14-pin so (derate 8.3mw/? above +70?).............. 667mw operating temperature range ........................ -40? to +125? junction temperature ..................................................... +150? storage temperature range ............................ -65? to +150? lead temperature (soldering, 10s) ................................ +300? a v(cl) = 1, no sustained oscillations ? = 10khz t a = +25? ? = 10khz measured from 10% to 90% of 4v p-p step (note 2) c l = 10pf c l = 10pf r l = 100k ? 2.7v v dd 5.5v c l = 10pf v ss v cm v dd inferred from cmrr test t a = t min to t max (note 3) (note 3) sourcing or sinking r l = 2k ? conditions pf 300 capacitive-load drive fa hz 1 i n current-noise density nv/ hz 12 e n voltage-noise density v/? 10 sr slew rate db 10 gain margin degrees 60 phase margin pf 5 c in input capacitance mhz 10 gbwp gain-bandwidth product ma ?0 i out(sc) output short-circuit current 65 85 mv ?.5 ?0 v os input offset voltage ma 0.8 2 i s v 2.7 5.5 v dd supply voltage range supply current (per amplifier) db 110 a v large-signal voltage gain db 65 100 psrr power-supply rejection ratio db 54 75 cmrr common-mode rejection ratio v v ss v dd v cm input common-mode range 16 na ?.05 ?.5 i b input bias current na ?.05 ?.5 i os input offset current m ? 1000 r in input resistance units min typ max symbol parameter note 1: all units production tested at t a = +25?. limits over temperature guaranteed by design. note 2: guaranteed by the power-supply rejection ratio (psrr) test. note 3: input offset voltage, input bias current, and input offset current are all tested and guaranteed at both ends of the common- mode range. (v ss + 0.25v) v out (v dd - 0.25v) r l = 100k ? r l = 2k ? 55 200 mv 1.5 v oh output-voltage swing high specified as v dd - v oh r l = 100k ? r l = 2k ? 35 150 mv 1.5 v ol output-voltage swing low specified as v ol - v ss (note 3)
MAX4490/max4491/max4492 low-cost, high-slew-rate, rail-to-rail i/o op amps in sc70 _______________________________________________________________________________________ 3 500 600 550 700 650 800 750 850 -40 -10 5 20 -25 35 50 65 80 95 110 125 supply current per amplifier vs. temperature MAX4490 toc 01 temperature ( c) supply current ( a) v dd = 5v v dd = 2.7v 0 300 200 100 500 400 900 800 700 600 1000 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5. 5 supply current per amplifier vs. supply voltage MAX4490 toc02 supply voltage (v) supply current ( a) -2.0 -1.4 -1.6 -1.8 -1.0 -1.2 -0.2 -0.4 -0.6 -0.8 0 -40 -25 -10 5 20 35 50 80 65 95 125 110 input offset voltage vs. temperature MAX4490 toc03 temperature ( c) offset voltage (mv) 0 20 10 30 60 70 50 40 80 -40 -10 5 20 35 -25 50 65 80 95 110 125 output swing high vs. temperature MAX4490 toc04 temperature ( c) v dd - v out (mv) v dd = 5v r l = 2k ? v dd = 2.7v r l = 2k ? v dd = 5v or 2.7v r l = 100k ? 0 20 10 30 60 70 50 40 80 -40 -10 5 20 35 -25 50 65 80 95 110 125 output swing low vs. temperature MAX4490 toc05 temperature ( c) v out - v ss (mv) v dd = 5v r l = 2k ? v dd = 2.7v r l = 2k ? v dd = 5v or 2.7v r l = 100k ? -20 0 -10 10 40 50 30 20 60 100 1k 10k 100k 1m 10m op amp gain and phase vs. frequency frequency (hz) gain (db) -180 -90 -135 -45 90 135 45 0 180 phase (degrees) MAX4490 toc06 gain phase a v = 1000 c l = 10pf -20 0 -10 10 40 50 30 20 60 100 1k 10k 100k 1m 10m gain and phase vs. frequency (with c load ) MAX4490 toc07 frequency (hz) gain (db) a v = 1000 c load = 200pf -180 -90 -135 -45 90 135 45 0 180 phase (degrees) gain phase 80 90 100 110 120 130 -40 -10 5 -25 20 35 50 65 80 95 110 125 large-signal gain vs. temperature MAX4490 toc08 temperature ( c) large-signal gain (db) v dd = 5v -100 -70 -60 -90 -80 -30 -40 -50 -10 -20 0 10 1k 10k 100 100k 1m 10m power-supply rejection ratio vs. frequency MAX4490 toc09 frequency (hz) pssr (db) a v = 1 typical operating characteristics (v dd = 5v, v ss = 0, v cm = v dd /2, r l = 100k ? to v dd /2, t a = +25?, unless otherwise noted.)
MAX4490/max4491/max4492 low-cost, high-slew-rate, rail-to-rail i/o op amps in sc70 4 _______________________________________________________________________________________ typical operating characteristics (continued) (v dd = 5v, v ss = 0, v cm = v dd /2, r l = 100k ? to v dd /2, t a = +25?, unless otherwise noted.) 0.01 1 0.1 10 100 1k 1k 10k 100 100k 1m 10m output impedance vs. frequency MAX4490 toc10 frequency (hz) output impedance ( ? ) a v = 1 0.040 0 10 100 1k 10k 100k total harmonic distortion plus noise vs. frequency 0.005 0.010 MAX4490 toc11 frequency (hz) thd + noise (%) 0.015 0.020 0.025 0.030 0.035 a v = 1v/v 2vp-p signal 500khz lowpass filter r l = 2k ? r l = 10k ? large-signal transient response (noninverting) a v = 1 in out 40 s/div v/div v/div MAX4490toc12 large-signal transient response (inverting) a v = -1 in out 2v/div 2v/div 40 s/div MAX4490toc13 small-signal transient response (noninverting) a v = 1 40 s/div in out 50mv/div 50mv/div MAX4490toc14 small-signal transient response (inverting) a v = -1 in out 40 s/div MAX4490toc15 50mv/div 50mv/div power-up transient response a v = 1, v in connected to v dd /2, r l = 2k ? v dd out 2v/div 1v/div MAX4490toc16 4 s/div 0 4 2 8 6 10 12 2.5 3.5 4.0 3.0 4.5 5.0 5.5 slew rate vs. supply voltage MAX4490 toc17 supply voltage (v) slew rate (v/ s) a v = 1 10% to 90% step 0 -20 -40 -120 0.001 1 10 100 0.01 0.1 1000 max4491/max4492 crosstalk vs. frequency -60 -80 -100 max4492toc18 frequency (mhz) crosstalk (db)
MAX4490/max4491/max4492 low-cost, high-slew-rate, rail-to-rail i/o op amps in sc70 _______________________________________________________________________________________ 5 name function MAX4490 1 in+ noninverting input pin 2 v ss negative supply input. connect to ground for single-supply operation. 3 in- inverting input ina- inverting input to amplifier a ina+ noninverting input to amplifier a 5 v dd positive supply input 4 out amplifier output inc+, ind+ noninverting inputs to amplifiers c and d outb amplifier b output inb- inverting input to amplifier b inb+ noninverting input to amplifier b outa amplifier a output pin description max4492 11 2 3 4 10, 12 7 6 5 1 max4491 4 2 3 8 7 6 5 1 9, 13 inc-, ind- inverting inputs to amplifiers c and d 8, 14 outc, outd amplifiers c and d outputs detailed description rail-to-rail input stage the MAX4490/max4491/max4492 cmos operational amplifiers have parallel-connected n- and p-channel differential input stages that combine to accept a com- mon-mode range extending to both supply rails. the n- channel stage is active for common-mode input voltages typically greater than (v ss + 1.2v), and the p- channel stage is active for common-mode input volt- ages typically less than (v dd - 1.2v). rail-to-rail output stage the MAX4490/max4491/max4492 cmos operational amplifiers feature class-ab push-pull output stages that can drive a 100k ? load to within 1.5mv of either supply rail. short-circuit output current is typically ?0ma. figures 1a and 1b show the typical temperature depen- dence of output source and sink currents, respectively, for three fixed values of (v dd - v oh ) and (v ol - v ss ). for example, at v dd = 5.0v, the load currents that main- tain (v dd - v oh ) = 100mv and (v ol - v ss ) = 100mv at t a = +25 c are 2.2ma and 3.3ma, respectively, when the load is connected to v dd /2. consistent resistive- drive capability is (2.5 - 0.1) / 2.2 = 1.1k ? . for the same application, resistive-drive capability is 2.2k ? when the load is connected to v dd or v ss . applications information power-supply considerations the MAX4490/max4491/max4492 operate from a sin- gle 2.7v to 5.5v supply or from dual ?.35v to ?.75v supplies with typically 800? supply current per ampli- fier. a high power-supply rejection ratio of 100db allows for extended operation from a decaying battery voltage, thereby simplifying designs for portable appli- cations. for single-supply operation, bypass the power supply with a 0.1? ceramic capacitor placed close to the v dd pin. for dual-supply operation, bypass each supply to ground. input capacitance one consequence of the parallel-connected differential input stages for rail-to-rail operation is a relatively large input capacitance c in (typically 5pf). this introduces a
pole at frequency (2 r c in ) -1 , where r is the parallel combination of the gain-setting resistors for the invert- ing or noninverting amplifier configuration (figure 2). if the pole frequency is less than or comparable to the unity-gain bandwidth (10mhz), the phase margin will be reduced, and the amplifier will exhibit degraded ac performance through either ringing in the step response or sustained oscillations. the pole frequency is 10mhz when r = 3.2k ? . to maximize stab ility, r <3k ? is recommended. applications that require rail-to-rail operation with mini- mal loading (for small v dd - v oh and v ol - v ss ) will typically require r values >3k ? . to improve step response under these conditions, connect a small capacitor c f between the inverting input and output. choose c f as follows: c f = 5(r / r f ) [pf] where r f is the feedback resistor and r is the gain-set- ting resistor (figure 2). figure 3 shows the step response for a noninverting amplifier subject to r = 4k ? with and without the c f feedback capacitor. MAX4490/max4491/max4492 low-cost, high-slew-rate, rail-to-rail i/o op amps in sc70 6 _______________________________________________________________________________________ figure 1a. output source current vs. temperature figure 1b. output sink current vs. temperature 0 1 2 3 4 5 6 -40 -10 -25 5 20 35 50 65 80 125 95 110 temperature ( c) output source current (ma) v dd - v oh = 200mv v dd - v oh = 100mv v dd - v oh = 50mv v dd = 5v v dd = 2.7v 0 1 2 3 4 5 6 7 8 9 -40 -10 -25 5 20 35 65 50 80 110 95 125 temperature ( c) output sink current (ma) v dd - v oh = 200mv v dd - v oh = 100mv v dd - v oh = 50mv v dd = 5v v dd = 2.7v figure 2. inverting and noninverting amplifier with feedback compensation MAX4490 v in v out r = r || r f r f c f = rc in r f c f r MAX4490 v in v out r = r || r f r f c f = rc in r f r c f inverting noninverting
driving capacitive loads in conjunction with op amp output resistance, capaci- tive loads introduce a pole frequency that can reduce phase margin and lead to unstable operation. the MAX4490/max4491/max4492 drive capacitive loads up to 300pf without significant degradation of step response and slew rate (figure 4). capacitive-load stability (page 1) shows regions of stable and margin- ally stable (step overshoot <10%) operation for different combinations of capacitive and resistive loads. improve stability for large capacitive loads by adding an isolation resistor (typically 10 ? ) in series with the output (figure 5). note that the isolation resistor forms a voltage divider with potential for gain error. chip information MAX4490 transistor count: 60 max4491 transistor count: 120 max4492 transistor count: 240 substrate connected to v ss MAX4490/max4491/max4492 low-cost, high-slew-rate, rail-to-rail i/o op amps in sc70 _______________________________________________________________________________________ 7 figure 4. step response with and without capacitive loading a v = +1, r l = 100k ?, c l = 0 4a) 4b) without capacitive loading with capacitive loading a v = +1, r l = 100k ?, c l = 300pf figure 3. step response with and without feedback compensation a v = -1, r l = 4k ?, c f = 0 3a) 3b) without feedback compensation with feedback compensation a v = -1, r l = 4k ? , c f = 5pf
MAX4490/max4491/max4492 low-cost, high-slew-rate, rail-to-rail i/o op amps in sc70 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 2001 maxim integrated products printed usa is a registered trademark of maxim integrated products. figure 5. isolation resistor for large capacitive loads MAX4490 v in v out c load r s package information pin configurations/ functional diagrams (continued) top view 1 2 3 4 8 7 6 5 v dd outb inb- inb+ v ss ina+ ina- outa sot23-8/ max + - + - max4491 14 13 12 11 10 9 8 1 2 3 4 5 6 7 outd ind- ind+ v ss v dd ina+ ina- outa max4492 inc+ inc- outc outb inb- inb+ tssop/so + - + - + - + - sc70, 5l.eps
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