AD294_15 AD | Alldatasheet
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Technical content
-.ANALOG W DEVICES I
FEATURES
High Common-Mode Voltage: AD293 :!:2500V peak max, cont. AD294 :!:3500 peak max, cont.;:!:8000V peak max Pulse Nonlinearity::!:0.05% max (AD293B) AdjustableInput & Output Gain: 1VN to 1000VN Meets UL Std 544 Leakage: 2.0fJ.Amax @ 115V ac, 60Hz
APPLICATIONS
Off Ground SignalMeasurement IndustrialControl Nuclear Instrumentation High Voltage ProtectionforData AcquisitionSystems Medical Diagnosticand PatientMonitoring Equipment GENERAL DESCRIPTION The AD293/AD294 are low cost,high performance isolation amplifiersdesigned foraccurateprocessingof low level, industrialsensoror biomedicalsignals,with truegalvanic isolationfrom high common-mode voltages,transientsand lethal ground faultcurrents.The true hybrid architectureof the AD293/AD294 includesa proprietaryhybrid magnetic trans- former, allhoused in a low profile(0.3")epoxy sealed,.40-pin ceramic package. The AD293 featuresa maximum nonlinearityof 0.1% (AD293A) or 0.05% (AD293B) and maximum common-mode voltage isolationof either2500V peak (continuousac or dc) or 2500V rms (ac60Hz, I minute). The AD294A providesa maximum nonlinearityof 0.1% and maximum common-mode voltage isolationof 3500V peak (continuousac,dc) and common-mode voltagepulse (defibrillator)or transientprotectionof :t8000V peak. In medical applicationsrequiringpatientisolationfrom lethal ground faultcurrents,the AD293/AD294 meet UL STD 544 leakage requirements by guaranteeinga maximum leakage currentof 2J.LArms (1l5V, 60Hz). All versionsprovide small signal(- 3dB) frequency responseof 2.5kHz and a fullpower responseof 200Hz (atgain of IVIV). Both the input and output sectionsof the AD293/AD294 are gain programmable, allowingthe user to tailorthe amplifierto meet an applicationrequirement. --- HybridIndustrial/ MedicalIsolationAmplifier AD293/AD294I AD293/AD294 FUNCTIONAL BLOCK DIAGRAM AD293/AD294 INPUT T1 OUTPUT -1JV \\-" WHERE TO USE THE AD293/AD294 Industrial:In processcontrolsystems,high CM V instrumentation and multi-channelcomputer interfacesystems,theAD293/AD294 provide guaranteedprotectionagainsthigh transientvoltages, lethalground faultcurrentsand high common-mode voltages. Medical: In biomedicaland patientmonitoring equipment such as ECG recorders,diagnosticsystems and blood pressure monitors,the AD294A offersprotectionfrom lethalground faultcurrentsas well as 8kV peak defibrillatorpulseinputs. Low levelsignalrecordingand monitoring isachievedwith the AD294A's low input noise (l°J.LVPop (((1G = 1O0VIV) high CMR (lOOdB min (ill60Hz). DESIGN FEATURES AND USER BENEFITS Adjustable Gain: Gain can be selectedatdther the input, output,or both. Thus, circuitresponsecan be tailoredto the user'sapplication.The input gain can be selectedfrom IVIV to 1O0VN with a singleresistor.The output gain can be selected from IVN to IOVN with or without compensation. The AD293/AD294 providesthe user with flexibilityforcircuit optimizationwithout requiringexternalactivecomponents. Buffered Output: The AD293/AD294 prevent inaccuracies relatedto low impedance loadsby providingan uncommitted output amplifiercapableof supplying :tIOV (llSmA min. OBSOLETE
SPECIFICATIONS(typical@ + 25"C,& Vs = 15Vunlessotherwisenoted) MODEL PIN DESIGNATIONS AD293A AD293B AD294A GAIN Range Formula (Input) (Output) Deviationfrom Formula G=I G>I vs.Temperature (- 25"C to + 85"C),.2(Gain= I) (Gain> 1) Nonlinearity(ot5V swing)' INPUT VOLTAGE RATINGS Linear DifferentialRange Max SafeDifferentialInput Continuous IMinute Max CMv (InpUtstoOutputs) Continuous (acordc) ac,60Hz, I minUte Duration Pulse,IOms Duration, I pulseilOsec CMR(60Hz),G = IOV/V Rs'" Ikf!Balanced Source Impedance Rs'" Ik Source Impedance Imbalance Rs '"5k Balanced Source Impedance Rs '"5k Source Impedance Imbalance Leakage Current,Input toOUtput euIl5Vac,60Hz InpUt Impedance, G = I Different;al Overload Common Mode Input BiasCurrent Initialen'+ 25 "C vs.Temperature Input Noise Voltage 0.05Hz to 100Hz 10Hz to IkHz Current 0.05Hz to 100Hz I to IOOOV/v lOOk )G'N ~ I + ~ ;RG '"Ikf!;G'N max = 100G GOUT = (I + ::); I "'GOUT'" 1O;GOUTmax = 10 ot1.0% ot3.0% ot60ppm/"Cmax ot120ppmrCmax ctO.I%max ctO.O5%max ot5Vmin ot3500V peak 3500V rIDS ot8000V peak fOOdS 95dB min FREQUENCY RESPONSE SmaIiSignal(-3dB)G = IV/VtoIOOVIV FullPower, 20V p-pOutput (IOV p-pAD294) G = IV/V(G'N = IV/V, GOUT = lV/V) G = 100V/V(G'N = IOOV/v, GOUT = IV/V) G = IOV/V(G;N ~ IV/V,GOUT ~ IOV/V) Slew Rate ctIOV min 120Vrmsmax 240Vrms.max ot2500V peak 2500V rIDS 1O8dB lOOdBmin 2fLA rIDS max 150pFIlIO'f! 1O0kn 30pFII(5x lO,on) 2nA (5nA max) 20pArC IOfLVp-P 5fLVrms 50pAp-p 2.SkHz 200Hz 100Hz 1.5kHz 9.IV/ms OFFSET VOLTAGE, REFERRED TO INPUT Inital,~"+ 2S"C,max vs.Temperature (Oto + 70"C) (-25"Cto + 85"C)max vs.Supply Voltage (ot3ot G22 )mvIN (ot3otGI50)fLV/"CIN (:tIO:tbOO)fLV/"CmaxIN (ctO.0Iot G 3 )mv/VIN (otSotG2S0)fLV/OCIN (ot lOot3GOO)fLV/oC maxIN (ot lOot GIOOO)fLVrCIN RATED OUTPUT Voltage,2kn Load Output Impedance Output Ripple,(dcto 100kHz) Bandwidth POWER SUPPLY' Voltagc,Rated Performance Voltage,Operating. Current,Quiescent(Vs = ot15V) (+Vosc~ +15V) ISOLATED POWER TEMPERATURE RANGE Rated Performance Operating :tIOV min <In 4m V p-p otl5Vdcct3% ct12Vdc ot18Vdc +lmA,-lmA +llmA -13Vdc~1200fLA -25"Cto+85"C -40"Cto + 100"C CASE DIMENSIONS PACKAGE OPTION' HY20A NOTES VOL. I,5-14 'R""mm<nd,d I"w" "",ply,ADI Madd 904. ' ISV "" SOmA 0","01. 'O",,,",Sw;o, 0 66V, 'SIC S,etioo 19 for p"kag' oolho, ;ofou"";oo. S"",ifiwioo, ,ubi'" 10 ,baog' wiliiouloolie,. INSTRUMENTA TlON & ISOLA TlON AMPLIFIERS ~--- I I PIN FUNCTION PIN FUNCTION
1 RG 40 HI-IN
2 COM'N
3 -v os TRIM 38 INPUT FILTER
4 LO-IN 37 -13V
17 COMosc 24 VOUT
20 SYNC 21 COMouT
traditionalwire wound methods. pick-up can be minimized (shown in Figure I). 1.GAIN RESISTORS RG. RA AND Re. 1% 50ppm/oC METAL FILM TYPE.
- INPUT GAIN =1 + ~; RG ;31k;MAX INPUT GAIN =100VN.
- OUTPUT GAIN =1 +:; ;1 " OUTPUT GAIN" 10.
FOR OUTPUT GAIN> 1.A 33pF MAY BE REQUIRED ACROSS RA.
- RD IS REQUIRED ONLY FOR THE AD294 TO PROVIDE PROTECTION
AGAINST DEFIBRILLATOR PULSES. USE TWO 240kH 1/2 WATT RESISTORS. WHEN MOUNTING. PLACE THEM IN SERIES AND AWAY FROM THE PCB. Figure 1. Basic IsolatorInterconnection leakage resistanceexceeding 3.4 x 1O9.n.
gain= IOOVN (GIN = IOVN; GOUT = IOVN). Figure 4. Recommended Offset & Gain Adjustments I. Set GOUT = IVN by disconnectingRfjfrom COM.
- Apply EIN = 0 voltsand adjustRIN forEo = 0 volts.
- Adjust ROUT forEo = 0 volts.
- Set GOUT = IVN by disconnectingRB from COM.
- Apply EIN = + l.OOOVand adjust~I forEo = + IO.OOOV.
- Apply EIN = + O.IOOV and adjustRGo forEo = + 1O.OOOV.
noiseand high common-mode voltages. Figure 6. TypicaIAD293/AD294-CMRvs. Frequency shown, increasingisolatorgain increasesCMR. CMR VALUE GIVEN <DR WORST CASE RESISTOR COMBINATION. dependent on gain and bandwidth as illustratedin Figure 8.
2 POLE
Figure8. TypicalAD293/AD294 - InputNoise vs.