LMC6034IM中文资料

LMC6034CMOS Quad Operational AmplifierGeneral DescriptionThe LMC6034is a CMOS quad operational amplifier which can operate from either a single supply or dual supplies.Its performance features include an input common-mode range that reaches ground,low input bias current,and high voltage gain into realistic loads,such as 2k Ωand 600Ω.This chip is built with National’s advanced Double-Poly Silicon-Gate CMOS process.See the LMC6032datasheet for a CMOS dual operational amplifier with these same features.For higher performance characteristics refer to the LMC660.Featuresn Specified for 2k Ωand 600Ωloads n High voltage gain:126dBn Low offset voltage drift: 2.3µV/˚C n Ultra low input bias current:40fA n Input common-mode range includes V −n Operating Range from +5V to +15V supply n I SS =400µA/amplifier;independent of V +n Low distortion:0.01%at 10kHz n Slew rate: 1.1V/µsnImproved performance over TLC274Applicationsn High-impedance buffer or preamplifier n Current-to-voltage converter n Long-term integrator n Sample-and-hold circuit nMedical instrumentationConnection DiagramOrdering InformationTemperature RangePackageNSC DrawingTransport MediaIndustrial −40˚C ≤T J ≤+85˚CLMC6034IN 14-Pin N14ARailMolded DIP LMC6034IM14-Pin M14ARail Small OutlineTape and Reel14-Pin DIP/SODS011134-1Top ViewMay 1998LMC6034CMOS Quad Operational Amplifier©1999National Semiconductor Corporation Absolute Maximum Ratings(Note1)If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Differential Input Voltage±Supply Voltage Supply Voltage(V+−V−)16V Output Short Circuit to V+(Note10) Output Short Circuit to V−(Note2) Lead Temperature(Soldering,10sec.)260˚C Storage Temperature Range−65˚C to+150˚C Power Dissipation(Note3) Voltage at Output/Input Pin(V+)+0.3V,(V−)−0.3V Current at Output Pin±18mA Current at Input Pin±5mA Current at Power Supply Pin35mA Junction Temperature(Note3)150˚C ESD Tolerance(Note4)1000VOperating Ratings(Note1)Temperature Range−40˚C≤T J≤+85˚C Supply Voltage Range 4.75V to15.5V Power Dissipation(Note11) Thermal Resistance(θJA),(Note12)14-Pin DIP85˚C/W 14-Pin SO115˚C/WDC Electrical CharacteristicsUnless otherwise specified,all limits guaranteed for T J=25˚C.Boldface limits apply at the temperature extremes.V+=5V, V−=GND=0V,V CM=1.5V,V OUT=2.5V,and R L>1M unless otherwise specified.Symbol Parameter Conditions Typical(Note5)LMC6034I Units Limit(Note6)V OS Input Offset Voltage19mV11max ∆V OS/∆T Input Offset Voltage 2.3µV/˚C Average DriftI B Input Bias Current0.04pA200max I OS Input Offset Current0.01pA100max R IN Input Resistance>1TeraΩCMRR Common Mode0V≤V CM≤12V8363dB Rejection Ratio V+=15V60min +PSRR Positive Power Supply5V≤V+≤15V8363dB Rejection Ratio V O=2.5V60min −PSRR Negative Power Supply0V≤V−≤−10V9474dB Rejection Ratio70min V CM Input Common-Mode V+=5V&15V−0.4−0.1V Voltage Range For CMRR≥50dB0maxV+−1.9V+−2.3VV+−2.6min A V Large Signal Voltage Gain R L=2kΩ(Note7)2000200V/mVSourcing100minSinking50090V/mV40minR L=600Ω(Note7)1000100V/mVSourcing75minSinking25050V/mV20min 2DC Electrical Characteristics(Continued)Unless otherwise specified,all limits guaranteed for T J=25˚C.Boldface limits apply at the temperature extremes.V+=5V, V−=GND=0V,V CM=1.5V,V OUT=2.5V,and R L>1M unless otherwise specified.Symbol Parameter Conditions Typical(Note5)LMC6034I Units Limit(Note6)V O Output Voltage Swing V+=5V 4.87 4.20VR L=2kΩto2.5V 4.00min0.100.25V0.35maxV+=5V 4.61 4.00VR L=600Ωto2.5V 3.80min0.300.63V0.75maxV+=15V14.6313.50VR L=2kΩto7.5V13.00min0.260.45V0.55maxV+=15V13.9012.50VR L=600Ωto7.5V12.00min0.79 1.45V1.75maxI O Output Current V+=5V2213mASourcing,V O=0V9minSinking,V O=5V2113mA9minV+=15V4023mASourcing,V O=0V15minSinking,V O=13V3923mA(Note10)15minI S Supply Current All Four Amplifiers 1.5 2.7mAV O=1.5V 3.0max3AC Electrical CharacteristicsUnless otherwise specified,all limits guaranteed for T J=25˚C.Boldface limits apply at the temperature extremes.V+=5V, V−=GND=0V,V CM=1.5V,V OUT=2.5V,and R L>1M unless otherwise specified.Symbol Parameter Conditions Typical(Note5)LMC6034I Units Limit(Note6)SR Slew Rate(Note8) 1.10.8V/µs0.4min GBW Gain-Bandwidth Product 1.4MHz φM Phase Margin50Deg G M Gain Margin17dBAmp-to-Amp Isolation(Note9)130dB enInput-Referred Voltage Noise F=1kHz22Typical Performance CharacteristicsV S =±7.5V,T A =25˚C unless otherwise specified (Continued)Applications HintAmplifier TopolgyThe topology chosen for the LMC6034,shown in Figure 1,is unconventional (compared to general-purpose op amps)in that the traditional unity-gain buffer output stage is not used;instead,the output is taken directly from the output of the in-tegrator,to allow a larger output swing.Since the buffer tra-ditionally delivers the power to the load,while maintaining high op amp gain and stability,and must withstand shorts to either rail,these tasks now fall to the integrator.As a result of these demands,the integrator is a compound affair with an embedded gain stage that is doubly fed forward (via C f and Cff)by a dedicated unity-gain compensation driver.In addition,the output portion of the integrator is a push-pull configuration for delivering heavy loads.While sinking current the whole amplifier path consists of three gain stages with one stage fed forward,whereas while sourcing the path contains four gain stages with two fed forward.Output Characteristics Current SourcingDS011134-27Input Voltage Noise vs FrequencyDS011134-28CMRR vs FrequencyDS011134-29Open-Loop Frequency Response DS011134-30Frequency Response vs Capacitive Load DS011134-31Non-Inverting Large Signal Pulse ResponseDS011134-32Stability vsCapacitive LoadDS011134-33Stability vsCapacitive LoadDS011134-34Note:Avoid resistive loads of less than 500Ω,as they may cause instability.5Applications Hint(Continued)The large signal voltage gain while sourcing is comparableto traditional bipolar op amps,even with a600Ωload.Thegain while sinking is higher than most CMOS op amps,dueto the additional gain stage;however,under heavy load(600Ω)the gain will be reduced as indicated in the ElectricalCharacteristics.Compensating Input CapacitanceThe high input resistance of the LMC6034op amps allowsthe use of large feedback and source resistor values withoutlosing gain accuracy due to loading.However,the circuit willbe especially sensitive to its layout when these large-valueresistors are used.Every amplifier has some capacitance between each inputand AC ground,and also some differential capacitance be-tween the inputs.When the feedback network around anamplifier is resistive,this input capacitance(along with anyadditional capacitance due to circuit board traces,thesocket,etc.)and the feedback resistors create a pole in thefeedback path.In the following General Operational Amplifiercircuit,Figure2the frequency of this pole iswhere C S is the total capacitance at the inverting input,in-cluding amplifier input capcitance and any stray capacitancefrom the IC socket(if one is used),circuit board traces,etc.,and R P is the parallel combination of R F and R IN.This for-mula,as well as all formulae derived below,apply to invert-ing and non-inverting op-amp configurations.When the feedback resistors are smaller than a few kΩ,thefrequency of the feedback pole will be quite high,since C S isgenerally less than10pF.If the frequency of the feedbackpole is much higher than the“ideal”closed-loop bandwidth(the nominal closed-loop bandwidth in the absence of C S),the pole will have a negligible effect on stability,as it will addonly a small amount of phase shift.However,if the feedback pole is less than approximately6to10times the“ideal”−3dB frequency,a feedback capacitor,C F,should be connected between the output and the invert-ing input of the op amp.This condition can also be stated interms of the amplifier’s low-frequency noise gain:To main-tain stability a feedback capacitor will probably be needed ifwhereis the amplifier’s low-frequency noise gain and GBW is theamplifier’s gain bandwidth product.An amplifier’slow-frequency noise gain is represented by the formularegardless of whether the amplifier is being used in invertingor non-inverting mode.Note that a feedback capacitor ismore likely to be needed when the noise gain is low and/orthe feedback resistor is large.If the above condition is met(indicating a feedback capacitorwill probably be needed),and the noise gain is large enoughthat:the following value of feedback capacitor is recommended:Ifthe feedback capacitor should be:Note that these capacitor values are usually significantlysmaller than those given by the older,more conservative for-mula:Using the smaller capacitors will give much higher band-width with little degradation of transient response.It may benecessary in any of the above cases to use a somewhatlarger feedback capacitor to allow for unexpected stray ca-DS011134-3FIGURE1.LMC6034Circuit Topology(Each Amplifier)DS011134-4C S consists of the amplifier’s input capacitance plus any stray capacitancefrom the circuit board and socket.C F compensates for the pole caused byC S and the feedback resistors.FIGURE2.General Operational Amplifier Circuit 6Applications Hint(Continued)pacitance,or to tolerate additional phase shifts in the loop,orexcessive capacitive load,or to decrease the noise or band-width,or simply because the particular circuit implementa-tion needs more feedback capacitance to be sufficientlystable.For example,a printed circuit board’s stray capaci-tance may be larger or smaller than the breadboard’s,so theactual optimum value for C F may be different from the oneestimated using the breadboard.In most cases,the valuesof C F should be checked on the actual circuit,starting withthe computed value.Capacitive Load ToleranceLike many other op amps,the LMC6034may oscillate whenits applied load appears capacitive.The threshold of oscilla-tion varies both with load and circuit gain.The configurationmost sensitive to oscillation is a unity-gain follower.SeeTypical Performance Characteristics.The load capacitance interacts with the op amp’s output re-sistance to create an additional pole.If this pole frequency issufficiently low,it will degrade the op amp’s phase margin sothat the amplifier is no longer stable at low gains.As shownin Figure3,the addition of a small resistor(50Ωto100Ω)inseries with the op amp’s output,and a capacitor(5pF to10pF)from inverting input to output pins,returns the phasemargin to a safe value without interfering withlower-frequency circuit operation.Thus larger values of ca-pacitance can be tolerated without oscillation.Note that in allcases,the output will ring heavily when the load capacitanceis near the threshold for oscillation.Capacitive load driving capability is enhanced by using a pullup resistor to V+(Figure4).Typically a pull up resistor con-ducting500µA or more will significantly improve capacitiveload responses.The value of the pull up resistor must be de-termined based on the current sinking capability of the ampli-fier with respect to the desired output swing.Open loop gainof the amplifier can also be affected by the pull up resistor(see Electrical Characteristics).PRINTED-CIRCUIT-BOARD LAYOUTFOR HIGH-IMPEDANCE WORKIt is generally recognized that any circuit which must operatewith less than1000pA of leakage current requires speciallayout of the PC board.When one wishes to take advantageof the ultra-low bias current of the LMC6034,typically lessthan0.04pA,it is essential to have an excellent layout.For-tunately,the techniques for obtaining low leakages are quitesimple.First,the user must not ignore the surface leakage ofthe PC board,even though it may sometimes appear accept-ably low,because under conditions of high humidity or dustor contamination,the surface leakage will be appreciable.To minimize the effect of any surface leakage,lay out a ringof foil completely surrounding the LMC6034’s inputs and theterminals of capacitors,diodes,conductors,resistors,relayterminals,etc.connected to the op-amp’s inputs.See Figure5.To have a significant effect,guard rings should be placedon both the top and bottom of the PC board.This PC foilmust then be connected to a voltage which is at the samevoltage as the amplifier inputs,since no leakage current canflow between two points at the same potential.For example,a PC board trace-to-pad resistance of1012Ω,which is nor-mally considered a very large resistance,could leak5pA ifthe trace were a5V bus adjacent to the pad of an input.Thiswould cause a100times degradation from the LMC6034’sactual performance.However,if a guard ring is held within5mV of the inputs,then even a resistance of1011Ωwouldcause only0.05pA of leakage current,or perhaps a minor(2:1)degradation of the amplifier’s performance.See Fig-ures6,7,8for typical connections of guard rings for stan-dard op-amp configurations.If both inputs are active and athigh impedance,the guard can be tied to ground and stillprovide some protection;see Figure9.DS011134-5FIGURE3.Rx,Cx Improve Capacitive Load ToleranceDS011134-22pensating for Large Capacitive Loadswith a Pull Up ResistorDS011134-6FIGURE5.Example of Guard Ring in P.C.BoardLayout7Applications Hint(Continued)The designer should be aware that when it is inappropriate to lay out a PC board for the sake of just a few circuits,there is another technique which is even better than a guard ring on a PC board:Don’t insert the amplifier’s input pin into theboard at all,but bend it up in the air and use only air as an in-sulator.Air is an excellent insulator.In this case you may have to forego some of the advantages of PC board con-struction,but the advantages are sometimes well worth the effort of using point-to-point up-in-the-air wiring.See Figure 10.BIAS CURRENT TESTINGThe test method of Figure 11is appropriate for bench-testing bias current with reasonable accuracy.To understand its op-eration,first close switch S2momentarily.When S2is opened,thenA suitable capacitor for C2would be a 5pF or 10pF silver mica,NPO ceramic,or air-dielectric.When determining the magnitude of I b −,the leakage of the capacitor and socket must be taken into account.Switch S2should be left shorted most of the time,or else the dielectric absorption of the ca-pacitor C2could cause errors.Similarly,if S1is shorted momentarily (while leaving S2shorted)where C x is the stray capacitance at the +input.DS011134-7FIGURE 6.Guard Ring ConnectionsInverting AmplifierDS011134-8FIGURE 7.Guard Ring ConnectionsNon-Inverting AmplifierDS011134-9FIGURE 8.Guard Ring ConnectionsFollowerDS011134-10FIGURE 9.Guard Ring ConnectionsHowland Current PumpDS011134-11(Input pins are lifted out of PC board and soldered directly to components.All other pins connected to PC board.)FIGURE 10.Air WiringDS011134-12FIGURE 11.Simple Input Bias Current Test Circuit 8Typical Single-Supply Applications(V +=5.0VDC)Additional single-supply applications ideas can be found in the LM324datasheet.The LMC6034is pin-for-pin compat-ible with the LM324and offers greater bandwidth and input resistance over the LM324.These features will improve the performance of many existing single-supply applications.Note,however,that the supply voltage range of the LMC6034is smaller than that of the LM324.For good CMRR over temperature,low drift resistors should be used.Matching of R3to R6and R4to R7affect CMRR.Gain may be adjusted through R2.CMRR may be adjusted through R7.Oscillator frequency is determined by R1,R2,C1,and C2:fosc =1/2πRC,where R =R1=R2andC =C1=C2.This circuit,as shown,oscillates at 2.0kHz with a peak-to-peak output swing of 4.0V.Low-Leakage Sample-and-HoldDS011134-13Instrumentation AmplifierDS011134-14Sine-Wave OscillatorDS011134-151Hz Square-Wave OscillatorDS011134-16Power AmplifierDS011134-179Typical Single-Supply Applications(V +=5.0VDC)(Continued)10Hz Bandpass FilterDS011134-18f O =10Hz Q =2.1Gain =−8.810Hz High-Pass FilterDS011134-20f c =10Hz d =0.895Gain =12dB passband ripple1Hz Low-Pass Filter(Maximally Flat,Dual Supply Only)DS011134-19f c =1Hz d =1.414Gain =1.57High Gain Amplifier with OffsetVoltage ReductionDS011134-21Gain =−46.8Output offset voltage reduced to the level of the input offset voltage of the bottom amplifier (typically 1mV). 10Physical Dimensions inches(millimeters)unless otherwise notedSmall Outline Dual-In-Line Pkg.(M)Order Number LMC6034IMNS Package Number M14AMolded Dual-In-Line Pkg.(N)Order Number LMC6034INNS Package Number N14A11NotesLIFE SUPPORT POLICYNATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION.As used herein:1.Life support devices or systems are devices or systems which,(a)are intended for surgical implant into the body,or (b)support or sustain life,and whose failure to perform when properly used in accordance with instructions for use provided in the labeling,can be reasonably expected to result in a significant injury to the user.2.A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system,or to affect its safety or effectiveness.National Semiconductor Corporation AmericasTel:1-800-272-9959Fax:1-800-737-7018Email:support@National Semiconductor EuropeFax:+49(0)180-5308586Email:europe.support@Deutsch Tel:+49(0)180-5308585English Tel:+49(0)180-5327832Français Tel:+49(0)180-5329358Italiano 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