LF412 TI1 | Alldatasheet
Document overview
- Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
- PDF pages: 16
Technical content
LF412 Low Offset, Low Drift Dual JFET Input Operational Amplifier Literature Number: SNOSBH7D
January 28, 2010 Low Offset, Low Drift Dual JFET Input Operational Amplifier General Description These devices are low cost, high speed, JFET input opera- tional amplifiers with very low input offset voltage and guar- anteed input offset voltage drift. They require low supply current yet maintain a large gain bandwidth product and fast slew rate. In addition, well matched high voltage JFET input devices provide very low input bias and offset currents. The LF412 dual is pin compatible with the LM1558, allowing de- signers to immediately upgrade the overall performance of existing designs. These amplifiers may be used in applications such as high speed integrators, fast D/A converters, sample and hold cir- cuits and many other circuits requiring low input offset voltage and drift, low input bias current, high input impedance, high slew rate and wide bandwidth.
Features
■ Internally trimmed offset voltage: 1 mV (max) ■ Input offset voltage drift: 10 μV/°C (max) ■ Low input bias current: 50 pA ■ Low input noise current: ■ Wide gain bandwidth: 3 MHz (min) ■ High slew rate: 10V/ μs (min) ■ Low supply current: 1.8 mA/Amplifier ■ High input impedance: 10 12Ω ■ Low total harmonic distortion ≤0.02% ■ Low 1/f noise corner: 50 Hz ■ Fast settling time to 0.01%: 2 μs Typical Connection 565641
Ordering Information
X indicates electrical grade Y indicates temperature range “M” for military “C” for commercial Z indicates package type “H” or “N” Connection Diagrams Metal Can Package 565642 Order Number LF412MH, LF412CH See NS Package Number H08A or LF412MH/883 (Note 1) See NS Package Number H08C Dual-In-Line Package 565644 Order Number LF412ACN, LF412CN or LF412MJ/883 (Note 1) See NS Package Number J08A or N08E BI-FET II™ is a trademark of National Semiconductor Corporation. © 2010 National Semiconductor Corporation 5656 www.national.com LF412 Low Offset, Low Drift Dual JFET Input Operational Amplifier
Note 1: Available per JM38510/11905 Detailed Schematic 565632 www.national.com 2 LF412
Absolute Maximum Ratings (Note 2) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. (Note 11) LF412A LF412 Supply Voltage ±22V ±18V Differential Input Voltage ±38V ±30V Input voltage Range (Note 3) ±19V ±15V Output Short Circuit Duration ( Note 4) Continuous Continuous H Package N Package Power Dissipation (Note 12) (Note 5) 670 mW Tj max 150°C 115°C θjA (Typical) 152°C/W 115°C/W Operating Temp. Range (Note 6) (Note 6) Storage Temp. −65°C≤TA≤150° C −65°C≤TA≤150° C Range Lead Temp. (Soldering, 10 sec.) 260°C 260°C ESD Tolerance (Note 13) 1700V 1700V (Note 7) Symbol Parameter Conditions LF412A LF412 Units Min Typ Max Min Typ Max VOS Input Offset Voltage RS=10 kΩ, TA=25°C 0.5 1.0 1.0 3.0 mV ΔVOS/ΔT Average TC of Input RS=10 kΩ (Note 8) 7 10 7 20 μV/°C Offset Voltage IOS Input Offset Current VS=±15V Tj=25°C 25 100 25 100 pA (Note 7, Note 9) Tj=70°C 2 2 nA Tj=125°C 25 25 nA IB Input Bias Current VS=±15V Tj=25°C 50 200 50 200 pA (Note 7, Note 9) Tj=70°C 4 4 nA Tj=125°C 50 50 nA RIN Input Resistance Tj=25°C 1012 1012 Ω AVOL Large Signal Voltage VS=±15V, VO=±10V, 50 200 25 200 V/mV Gain RL=2k, TA=25°C Over Temperature 25 200 15 200 V/mV VO Output Voltage Swing VS=±15V, RL=10k ±12 ±13.5 ±12 ±13.5 V VCM Input Common-Mode ±16 +19.5 ±11 +14.5 V Voltage Range −16.5 −11.5 V CMRR Common-Mode RS≤10k 80 100 70 100 dB Rejection Ratio PSRR Supply Voltage (Note 10) 80 100 70 100 dB Rejection Ratio IS Supply Current VO = 0V, RL = ∞ 3.6 5.6 3.6 6.5 mA Note 2: “Absolute Maximum Ratings” indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is functional, but do not guarantee specific performance limits. (Note 7) Symbol Parameter Conditions LF412A LF412 Units Min Typ Max Min Typ Max Amplifier to Amplifier TA=25°C, f=1 Hz-20 kHz −120 −120 dB Coupling (Input Referred) SR Slew Rate VS=±15V, TA=25°C 10 15 8 15 V/μs GBW Gain-Bandwidth Product VS=±15V, TA=25°C 3 4 2.7 4 MHz 3 www.national.com LF412
Symbol Parameter Conditions LF412A LF412 Units Min Typ Max Min Typ Max THD Total Harmonic Dist AV=+10, RL=10k, VO=20 Vp-p, BW=20 Hz-20 kHz ≤0.02 ≤0.02 % en Equivalent Input Noise TA=25°C, RS=100Ω, 25 25 Voltage f=1 kHz in Equivalent Input Noise TA=25°C, f=1 kHz 0.01 0.01 Current Note 3: Unless otherwise specified the absolute maximum negative input voltage is equal to the negative power supply voltage. Note 4: Any of the amplifier outputs can be shorted to ground indefintely, however, more than one should not be simultaneously shorted as the maximum junction temperature will be exceeded. Note 5: For operating at elevated temperature, these devices must be derated based on a thermal resistance of θjA. Note 6: These devices are available in both the commercial temperature range 0°C≤TA≤70°C and the military temperature range −55°C≤TA≤125°C. The temperature range is designated by the position just before the package type in the device number. A “C” indicates the commercial temperature range and an “M” indicates the military temperature range. The military temperature range is available in “H” package only. In all cases the maximum operating temperature is limited by internal junction temperature Tj max. Note 7: Unless otherwise specified, the specifications apply over the full temperature range and for VS=±20V for the LF412A and for VS=±15V for the LF412. VOS, IB, and IOS are measured at VCM=0. Note 8: The LF412A is 100% tested to this specification. The LF412 is sample tested on a per amplifier basis to insure at least 85% of the amplifiers meet this specification. Note 9: The input bias currents are junction leakage currents which approximately double for every 10°C increase in the junction temperature, Tj. Due to limited production test time, the input bias currents measured are correlated to junction temperature. In normal operation the junction temperature rises above the ambient temperature as a result of internal power dissipation, PD. Tj=TA+θjA PD where θjA is the thermal resistance from junction to ambient. Use of a heat sink is recommended if input bias current is to be kept to a minimum. Note 10: Supply voltage rejection ratio is measured for both supply magnitudes increasing or decreasing simultaneously in accordance with common practice. VS = ±6V to ±15V. Note 11: Refer to RETS412X for LF412MH and LF412MJ military specifications. Note 12: Max. Power Dissipation is defined by the package characteristics. Operating the part near the Max. Power Dissipation may cause the part to operate outside guaranteed limits. Note 13: Human body model, 1.5 kΩ in series with 100 pF. Typical Performance Characteristics Input Bias Current 565610 Input Bias Current 565611 www.national.com 4 LF412
5 www.national.com LF412
Undistorted Output Voltage Swing 565623 www.national.com 6 LF412
7 www.national.com LF412
RL=2 kΩ, CL=10 pF Small Signal Inverting 565636 Small Signal Non-Inverting 565637 Large Signal Inverting 565638 Large Signal Non-Inverting 565639 www.national.com 8 LF412
Current Limit (RL=100Ω) 565640 Application Hints The LF412 series of JFET input dual op amps are internally trimmed (BI-FET II™) providing very low input offset voltages and guaranteed input offset voltage drift. These JFETs have large reverse breakdown voltages from gate to source and drain eliminating the need for clamps across the inputs. Therefore, large differential input voltages can easily be ac- commodated without a large increase in input current. The maximum differential input voltage is independent of the sup- ply voltages. However, neither of the input voltages should be allowed to exceed the negative supply as this will cause large currents to flow which can result in a destroyed unit. Exceeding the negative common-mode limit on either input will cause a reversal of the phase to the output and force the amplifier output to the corresponding high or low state. Exceeding the negative common-mode limit on both inputs will force the amplifier output to a high state. In neither case does a latch occur since raising the input back within the common-mode range again puts the input stage and thus the amplifier in a normal operating mode. Exceeding the positive common-mode limit on a single input will not change the phase of the output, however, if both inputs exceed the limit, the output of the amplifier may be forced to a high state. The amplifiers will operate with a common-mode input voltage equal to the positive supply; however, the gain bandwidth and slew rate may be decreased in this condition. When the neg- ative common-mode voltage swings to within 3V of the neg- ative supply, an increase in input offset voltage may occur. Each amplifier is individually biased by a zener reference which allows normal circuit operation on ±6.0V power sup- plies. Supply voltages less than these may result in lower gain bandwidth and slew rate. The amplifiers will drive a 2 kΩ load resistance to ±10V over the full temperature range. If the amplifier is forced to drive heavier load currents, however, an increase in input offset voltage may occur on the negative voltage swing and finally reach an active current limit on both positive and negative swings. Precautions should be taken to ensure that the power supply for the integrated circuit never becomes reversed in polarity or that the unit is not inadvertently installed backwards in a socket as an unlimited current surge through the resulting forward diode within the IC could cause fusing of the internal conductors and result in a destroyed unit. As with most amplifiers, care should be taken with lead dress, component placement and supply decoupling in order to en- sure stability. For example, resistors from the output to an input should be placed with the body close to the input to minimize “pick-up” and maximize the frequency of the feed- back pole by minimizing the capacitance from the input to ground. A feedback pole is created when the feedback around any amplifier is resistive. The parallel resistance and capacitance from the input of the device (usually the inverting input) to AC ground set the frequency of the pole. In many instances the frequency of this pole is much greater than the expected 3 dB frequency of the closed loop gain and consequently there is negligible effect on stability margin. However, if the feedback pole is less than approximately 6 times the expected 3 dB frequency a lead capacitor should be placed from the output to the input of the op amp. The value of the added capacitor should be such that the RC time constant of this capacitor and the resistance it parallels is greater than or equal to the original feedback pole time constant. 9 www.national.com LF412
Single Supply Sample and Hold 565631 www.national.com 10 LF412
Physical Dimensions inches (millimeters) unless otherwise noted Metal Can Package (H) Order Number LF412MH or LF412CH 11 www.national.com LF412
Metal Can Package (H) Order Number LF412MH/833 www.national.com 12 LF412
Dual-In-Line Package (J) Order Number LF412MJ/883 Dual-In-Line Package (N) Order Number LF412ACN or LF412CN 13 www.national.com LF412
LF412 Low Offset, Low Drift Dual JFET Input Operational Amplifier For more National Semiconductor product information and proven design tools, visit the following Web sites at: www.national.com Products Design Support Amplifiers www.national.com/amplifiers WEBENCH® Tools www.national.com/webench Audio www.national.com/audio App Notes www.national.com/appnotes Clock and Timing www.national.com/timing Reference Designs www.national.com/refdesigns Data Converters www.national.com/adc Samples www.national.com/samples Interface www.national.com/interface Eval Boards www.national.com/evalboards LVDS www.national.com/lvds Packaging www.national.com/packaging Power Management www.national.com/power Green Compliance www.national.com/quality/green Switching Regulators www.national.com/switchers Distributors www.national.com/contacts LDOs www.national.com/ldo Quality and Reliability www.national.com/quality LED Lighting www.national.com/led Feedback/Support www.national.com/feedback Voltage References www.national.com/vref Design Made Easy www.national.com/easy PowerWise® Solutions www.national.com/powerwise Applications & Markets www.national.com/solutions Serial Digital Interface (SDI) www.national.com/sdi Mil/Aero www.national.com/milaero Temperature Sensors www.national.com/tempsensors SolarMagic™ www.national.com/solarmagic PLL/VCO www.national.com/wireless PowerWise® Design University www.national.com/training THE CONTENTS OF THIS DOCUMENT ARE PROVIDED IN CONNECTION WITH NATIONAL SEMICONDUCTOR CORPORATION (“NATIONAL”) PRODUCTS. NATIONAL MAKES NO REPRESENTATIONS OR WARRANTIES WITH RESPECT TO THE ACCURACY OR COMPLETENESS OF THE CONTENTS OF THIS PUBLICATION AND RESERVES THE RIGHT TO MAKE CHANGES TO SPECIFICATIONS AND PRODUCT DESCRIPTIONS AT ANY TIME WITHOUT NOTICE. NO LICENSE, WHETHER EXPRESS, IMPLIED, ARISING BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS GRANTED BY THIS DOCUMENT. TESTING AND OTHER QUALITY CONTROLS ARE USED TO THE EXTENT NATIONAL DEEMS NECESSARY TO SUPPORT NATIONAL’S PRODUCT WARRANTY. EXCEPT WHERE MANDATED BY GOVERNMENT REQUIREMENTS, TESTING OF ALL PARAMETERS OF EACH PRODUCT IS NOT NECESSARILY PERFORMED. NATIONAL ASSUMES NO LIABILITY FOR APPLICATIONS ASSISTANCE OR BUYER PRODUCT DESIGN. BUYERS ARE RESPONSIBLE FOR THEIR PRODUCTS AND APPLICATIONS USING NATIONAL COMPONENTS. PRIOR TO USING OR DISTRIBUTING ANY PRODUCTS THAT INCLUDE NATIONAL COMPONENTS, BUYERS SHOULD PROVIDE ADEQUATE DESIGN, TESTING AND OPERATING SAFEGUARDS. EXCEPT AS PROVIDED IN NATIONAL’S TERMS AND CONDITIONS OF SALE FOR SUCH PRODUCTS, NATIONAL ASSUMES NO LIABILITY WHATSOEVER, AND NATIONAL DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY RELATING TO THE SALE AND/OR USE OF NATIONAL PRODUCTS INCLUDING LIABILITY OR WARRANTIES RELATING TO FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT. LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS PRIOR WRITTEN APPROVAL OF THE CHIEF EXECUTIVE OFFICER AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: Life support devices or systems are devices 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. A critical component is any component in 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 and the National Semiconductor logo are registered trademarks of National Semiconductor Corporation. All other brand or product names may be trademarks or registered trademarks of their respective holders. Copyright© 2010 National Semiconductor Corporation For the most current product information visit us at www.national.com National Semiconductor Americas Technical Support Center Email: support@nsc.com Tel: 1-800-272-9959 National Semiconductor Europe Technical Support Center Email: europe.support@nsc.com National Semiconductor Asia Pacific Technical Support Center Email: ap.support@nsc.com National Semiconductor Japan Technical Support Center Email: jpn.feedback@nsc.com www.national.com
Texas InstrumentsIncorporatedand itssubsidiaries(TI)reservetherighttomake corrections,modifications,enhancements,improvements, and otherchanges toitsproductsand servicesatany timeand todiscontinueany productorservicewithoutnotice.Customersshould obtainthelatestrelevantinformationbeforeplacingordersand shouldverifythatsuch informationiscurrentand complete.Allproductsare soldsubjecttoTI’s termsand conditionsofsalesuppliedatthetimeoforderacknowledgment. TIwarrantsperformanceofitshardwareproductstothespecificationsapplicableatthetimeofsaleinaccordancewithTI’s standard warranty.Testingand otherqualitycontroltechniquesareused totheextentTIdeems necessarytosupportthiswarranty.Exceptwhere mandated by governmentrequirements,testingofallparametersofeach productisnotnecessarilyperformed. TIassumes no liabilityforapplicationsassistanceorcustomerproductdesign.Customersareresponsiblefortheirproductsand applicationsusingTIcomponents.To minimizetherisksassociatedwithcustomerproductsand applications,customersshouldprovide adequatedesignand operatingsafeguards. TIdoes notwarrantorrepresentthatany license,eitherexpressorimplied,isgrantedunderany TIpatentright,copyright,mask work right, orotherTIintellectualpropertyrightrelatingtoany combination,machine,orprocessinwhichTIproductsorservicesareused.Information publishedby TIregardingthird-partyproductsorservicesdoes notconstitutea licensefromTItouse such productsorservicesora warrantyorendorsementthereof.Use ofsuch informationmay requirea licensefroma thirdpartyunderthepatentsorotherintellectual propertyofthethirdparty,ora licensefromTIunderthepatentsorotherintellectualpropertyofTI. ReproductionofTIinformationinTIdatabooks ordatasheetsispermissibleonlyifreproductioniswithoutalterationand isaccompanied by allassociatedwarranties,conditions,limitations,and notices.Reproductionofthisinformationwithalterationisan unfairand deceptive businesspractice.TIisnotresponsibleorliableforsuch altereddocumentation.Informationofthirdpartiesmay be subjecttoadditional restrictions. ResaleofTIproductsorserviceswithstatementsdifferentfromorbeyond theparametersstatedby TIforthatproductorservicevoidsall expressand any impliedwarrantiesfortheassociatedTIproductorserviceand isan unfairand deceptivebusinesspractice.TIisnot responsibleorliableforany such statements. TIproductsarenotauthorizedforuse insafety-criticalapplications(suchas lifesupport)where a failureoftheTIproductwouldreasonably be expectedtocause severepersonalinjuryordeath,unlessofficersofthepartieshave executedan agreementspecificallygoverning such use.Buyersrepresentthattheyhave allnecessaryexpertiseinthesafetyand regulatoryramificationsoftheirapplications,and acknowledgeand agreethattheyaresolelyresponsibleforalllegal,regulatoryand safety-relatedrequirementsconcerningtheirproducts and any use ofTIproductsinsuch safety-criticalapplications,notwithstandingany applications-relatedinformationorsupportthatmay be providedby TI.Further,Buyersmust fullyindemnifyTIand itsrepresentativesagainstany damages arisingoutoftheuse ofTIproductsin such safety-criticalapplications. TIproductsareneitherdesignednorintendedforuse inmilitary/aerospaceapplicationsorenvironmentsunlesstheTIproductsare specificallydesignatedby TIas military-gradeor"enhanced plastic." Onlyproductsdesignatedby TIas military-grademeet military specifications.Buyersacknowledgeand agreethatany such use ofTIproductswhichTIhas notdesignatedas military-gradeissolelyat theBuyer's risk,and thattheyaresolelyresponsibleforcompliancewithalllegaland regulatoryrequirementsinconnectionwithsuch use. TIproductsareneitherdesignednorintendedforuse inautomotiveapplicationsorenvironmentsunlessthespecificTIproductsare designatedby TIas compliantwithISO/TS 16949 requirements.Buyersacknowledgeand agreethat,iftheyuse any non-designated productsinautomotiveapplications,TIwillnotbe responsibleforany failuretomeet such requirements. FollowingareURLs where you can obtaininformationon otherTexas Instrumentsproductsand applicationsolutions: Products Applications Audio www.ti.com/audio Communicationsand Telecom www.ti.com/communications Amplifiers amplifier.ti.com Computers and Peripherals www.ti.com/computers Data Converters dataconverter.ti.com Consumer Electronics www.ti.com/consumer-apps DLP ® Products www.dlp.com Energyand Lighting www.ti.com/energy DSP dsp.ti.com Industrial www.ti.com/industrial Clocksand Timers www.ti.com/clocks Medical www.ti.com/medical Interface interface.ti.com Security www.ti.com/security Logic logic.ti.com Space,Avionicsand Defense www.ti.com/space-avionics-defense Power Mgmt power.ti.com Transportationand Automotive www.ti.com/automotive Microcontrollers microcontroller.ti.com Videoand Imaging www.ti.com/video RFID www.ti-rfid.com OMAP MobileProcessors www.ti.com/omap WirelessConnectivity www.ti.com/wirelessconnectivity TIE2E Community Home Page e2e.ti.com MailingAddress:Texas Instruments,PostOfficeBox 655303,Dallas,Texas 75265 Copyright© 2011,Texas InstrumentsIncorporated