|
If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
Datasheet File OCR Text: |
LT1002 Dual, Matched Precision Operational Amplifier FEATURES s DESCRIPTIO s s s s s s Guaranteed low offset voltage LT1002A 60V max LT1002 100V max Guaranteed offset voltage match LT1002A 40V max LT1002 80V max Guaranteed low drift LT1002A 0.9V/C max LT1002 1.3V/C max Guaranteed CMRR LT1002A 110dB min LT1002 110dB min Guaranteed channel separation LT1002A 132dB min LT1002 130dB min Guaranteed matching characteristics Low noise 0.35VP-P The LT (R)1002 dual, matched precision operational amplifiers combine excellent individual amplifier performance with tight matching and temperature tracking between amplifiers. In the design, processing, and testing of the device, particular attention has been paid to the optimization of the entire distribution of several key parameters and their matching. Consequently, the specifications of even the low cost commercial grade (LT1002C) have been spectacularly improved compared to presently available devices. Essentially, the input offset voltage of all units is less than 80V, and matching between amplifiers is consistently beter than 60V (see distribution plot below). Input bias and offset currents, channel separation, common mode and power suply rejections of the LT1002C are all specified at levels which were previsouly attainable only on very expensive, selected grades of other dual devices. Power dissipation is nearly halved compared to the most popular precision duals, without adversely affecting noise or speed performance. A by-product of lower dissipation is decreased warm-up drift. For even better performance in a single precision op amp, refer to the LT1001 data sheet. A bridge signal conditioning application is shown below. This circuit illustrates the requirement for both excellent matching and individual amplifier specifications. APPLICATIO S s s s s s s Thermocouple Amplifiers Strain Gauge Amplifiers Low level signal processing Medical instrumentation Precision dual limit threshold detection Instrumentation amplifiers , LTC and LT are registered trademarks of Linear Technology Corporation TYPICAL APPLICATIO 15V 8.2k 2k* 4 4.99k* Strain Gauge Signal Conditioner with Bridge Excitation 15V 100 5W Distribution of Offset Voltage Match REFERENCE OUT TO MONITORING A/D CONVERTER + 1/2 LT1002 13 2k IN4148 LM329 2N2219 3 - 3 350 BRIDGE 10k ZERO 2 + LT1001 6 1F 0V TO 10V OUT 340k* NUMBER OF UNITS 301k* - 10 - 1/2 LT1002 IN4148 6 2N2907 2k 100 5W *RN60C FILM RESISTORS -15V GAIN TRIM 1.1k* 11 + 1002 TA01 U 70 60 50 40 30 20 10 0 -100 -80 -60 -40 -20 0 20 40 60 80 100 INPUT OFFSET VOLTAGE MATCH (V) 1002 TA02 U U VS = 15V TA = 25C 287 UNITS TESTED 1002fb 1 LT1002 ABSOLUTE MAXIMUM RATINGS (Note 1) PACKAGE/ORDER INFORMATION TOP VIEW NULL (A) 1 NULL (A) 2 -IN (A) 3 +IN (A) 4 V- (B) 5 OUT (B) 6 V+ (B) 7 N PACKAGE 14 PIN PLASTIC - Supply Voltage (Note 7) ........................................ 22V Differential Input Voltage ...................................... 30V Input Voltage Equal to Supply Voltage Output Short Circuit Duration ......................... Indefinite Operating Temperature Range LT1002AM/LT1002M (OBSOLETE) .. - 55C to 125C LT1002AC/LT1002C ............................... 0C to 70C Storage Temperature Range All Grades ......................................... - 65C to 150C Lead Temperature (Soldering, 10 sec.)................. 300C 14 V+ (A) 13 OUT (A) A + ORDER PART NO. LT1002ACN LT1002CN 12 V- (A) + OFFSET VOLTAGE MAX at 25C 60V 100V B - 11 +IN (B) 10 -IN (B) 9 NULL (B) 8 NULL (B) TJMAX = 125C, JA = 100C/W NOTE: Device may be operated even if insertion is reversed; this is due to inherent symmetry of pin locations of amplifiers A and B. (Note 7) J PACKAGE 14 PIN HERMETIC TJMAX = 125C, JA = 100C/W LT1002AMJ LT1002MJ LT1002ACJ LT1002CJ 60V 100V 60V 100V OBSOLETE PACKAGE Consider the N Package for Alternate Source Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS, I DIVIDUAL A PLIFIERS VS = 15V, TA = 25C, unless otherwise noted SYMBOL VOS VOS Time IOS IB en en AVOL CMRR PSRR Rin VOUT SR GBW Pd PARAMETER Input Offset Voltage Long Term Input Offset Voltage Stability Input Offset Current Input Bias Current Input Noise Voltage Input Noise Voltage Density Large Signal Voltage Gain Common Mode Rejection Ratio Power Supply Rejection Ratio Input Resistance Differential Mode Input Voltage Range Maximum Output Voltage Swing Slew Rate Gain Bandwidth Product Power Dissipation per amplifier RL 2k RL 1k RL 2k (Note 5) (Note 5) No load No load, VS = 3V 0.1Hz to 10Hz (Note 3) fO = 10Hz (Note 6) fO = 1000Hz (Note 3) RL 2k, VO = 12V RL 1k, VO = 10V VCM = 13V VS = 3V to 18V (Note 5) 400 250 110 108 20 13 13 12 0.1 0.4 CONDITIONS (Note 2) (Notes 3 and 4) LT1002AM/LT1002AC MIN TYP MAX 20 60 0.3 0.3 0.6 0.35 10.3 9.6 800 500 126 123 100 14 14 13.5 0.25 0.8 46 4 75 7 1.5 2.8 3.0 0.7 20.0 11.5 350 220 110 105 13 13 13 12 0.1 0.4 LT1002M/LT1002C MIN TYP MAX 25 100 0.4 0.4 0.7 0.38 10.5 9.8 800 500 126 123 80 14 14 13.5 0.25 0.8 48 4 85 8 2.0 4.2 4.5 0.75 20.0 12.0 UNITS V V/month nA nA Vp-p nVHz V/mV dB dB M V V V/s MHz mW 1002fb 2 U W U W U U WW W LT1002 ELECTRICAL CHARACTERISTICS, I DIVIDUAL A PLIFIERS The q denotes the specifications which apply over the temperature range - 55C TA 125C, VS = 15V,unless otherwise noted. SYMBOL VOS VOS Temp IOS IB AVOL CMRR PSRR VOUT Pd PARAMETER Input Offset Voltage Average Input Offset Voltage Drift Input Offset Current Input Bias Current Large Signal Voltage Gain Common Mode Rejection Ratio Power Supply Rejection Ratio Input Voltage Range Output Voltage Swing Power Dissipation per amplifier RL 2k No load RL 2k, VO = 10V VCM = 13V VS = 3V to 18V CONDITIONS (Note 2) MIN q q q q q q q q q q LT1002AM TYP MAX 30 150 0.2 0.8 1.0 0.9 5.6 6.0 300 106 102 13 12.5 13.5 55 90 The q denotes the specifications which apply over the temperature range 0C TA 70C, VS = 15V, unless otherwise noted. SYMBOL VOS VOS Temp IOS IB AVOL CMRR PSRR VOUT Pd PARAMETER Input Offset Voltage Average Input Offset Voltage Drift Input Offset Current Input Bias Current Large Signal Voltage Gain Common Mode Rejection Ratio Power Supply Rejection Ratio Input Voltage Range Output Voltage Swing Power Dissipation per amplifier RL 2k No Load RL 2k, VO = 10V VCM = 13V VS = 3V to 18V CONDITIONS (Note 2) MIN q q q q q q q q q q LT1002AC TYP MAX 20 100 0.2 0.5 0.7 0.9 4.2 4.5 350 108 105 13 12.5 13.8 50 85 ATCHI G CHARACTERISTICS PARAMETER Input Offset Voltage Match Average Non-Inverting Bias Current Non-Inverting Offset Current Inverting Offset Current Common Mode Rejection Ratio Match Power Supply Rejection Ratio Match Channel Seperation VCM = 13V VS = 3V to 18V f 10Hz (Note 5) CONDITIONS LT1002AM/AC MIN TYP MAX - 15 40 - - - 110 108 132 0.6 0.6 0.6 132 130 148 3.5 3.5 3.5 - - - MIN - - - - 108 102 130 LT1002M/C TYP MAX 25 80 0.7 0.7 0.7 132 128 146 4.8 6.0 6.0 - - - UNITS V nA nA nA dB dB dB 1002fb VS = 15V, TA = 25C, unless otherwise noted. SYMBOL IB + IOS+ IOS - CMRR PSRR W 14 U MIN LT1002M TYP MAX 45 230 0.3 1.2 1.5 1.3 8.5 9.0 UNITS V V/C nA nA V/mV dB dB V V 700 122 117 200 104 96 13 12.0 700 120 117 14 13.5 60 100 mW MIN LT1002C TYP MAX 30 160 0.3 0.6 1.0 1.3 5.7 6.0 UNITS V V/C nA nA V/mV dB dB V V 750 124 120 14 250 106 100 13 12.5 750 123 120 14 13.8 55 90 mW U W 3 LT1002 ATCHI G CHARACTERISTICS PARAMETER Input Offset Voltage Match Input Offset Voltage Tracking Average Non-Inverting Bias Current CONDITIONS q q q q q The q denotes the specifications which apply over the temperature range - 55C TA 125C, VS = 15V, unless otherwise noted. SYMBOL MIN - - - - - 106 102 LT1002AM TYP MAX 50 140 0.3 1.5 1.5 1.5 126 122 1.0 6.0 6.5 6.5 MIN - - - - - 102 94 LT1002M TYP MAX 60 230 0.4 1.8 1.8 1.8 124 120 1.5 10.0 12.0 12.0 - - UNITS V V/C nA nA nA dB dB IB + IOS + Non-Inverting Offset Current Inverting Offset Current Common Mode Rejection Ratio Match Power Supply Rejection Ratio Match VCM = 13V VS = 3V to 18V IOS- CMRR PSRR The q denotes the specifications which apply over the temperature range 0C TA 70C, VS = 15V, unless otherwise noted. SYMBOL PARAMETER Input Offset Voltage Match Input Offset Voltage Tracking IB + Average Non-Inverting Bias Current + IOS Non-Inverting Offset Current Inverting Offset Current Common Mode Rejection Ratio Match Power Supply Rejection Ratio Match VCM = 13V VS = 3V to 18V IOS- CMRR PSRR For MIL-STD components, please refer to LTC 883C data sheet for test listing and parameters. Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: Offset voltage measured with high speed test equipment, approximately 1second after power is applied. Note 3: This parameter is tested on a sample basis only. Note 4: Long Term Input Offset Voltage Stability refers to the averaged trend line of VOS versus Time over extended periods after the first 30 days 4 U W q q CONDITIONS q q q q q q q MIN - - - - - LT1002AC TYP MAX 30 85 0.3 1.0 1.0 1.0 130 126 1.0 4.5 5.0 5.0 - - MIN - - - - - 105 98 LT1002C TYP MAX 45 150 0.4 1.2 1.2 1.2 128 124 1.5 7.0 8.5 8.5 - - UNITS V V/C nA nA nA dB dB 108 105 of operation. Excluding the initial hour of operation, changes in VOS during the first 30 operating days are typically 2.5V. Note 5: Parameter is guaranteed by design. Note 6: 10Hz noise voltage density is sample tested on every lot. Devices 100% tested at 10Hz are available on request. Note 7: The V + supply terminals are completely independent and may be powered by separate supplies if desired (this approach, however, would sacrifice the advantages of the power supply rejection ratio matching). The V - supply terminals are both connected to the common substrate and must be tied to the same voltage. Both V - pins should be used. 1002fb LT1002 TYPICAL PERFORMANCE CHARACTERISTICS Distribution of Offset Voltage of Individual Amplifiers 100 VS = 15V TA = 25C 574 UNITS TESTED 80 NUMBER OF UNITS 60 40 30 20 10 NUMBER OF UNITS NUMBER OF UNITS 40 20 0 -100 -80 -60 -40 -20 0 20 40 60 80 100 INPUT OFFSET VOLTAGE (V) 1002 G01 Offset Voltage Drift with Temperature of Six Representative Units INDIVIDUAL AMPLIFIER OFFSET VOLTAGE (V) 100 80 100 80 VS = 15V LT1002M LT1002AM CHANGE IN OFFSET VOLTAGE (MICROVOLTS) OFFSET VOLTAGE MATCH (V) 60 40 20 0 -20 -40 -60 -80 -100 -50 -25 LT1002M LT1002AM LT1002M LT1 002AM LT1002M 50 0 75 25 TEMPERATURE (C) Long Term Stability of Four Representative Units 10 OFFSET VOLTAGE CHANGE (V) VOLTAGE NOISE nV/Hz 30 1/f CORNER 4Hz VOLTAGE 3 0 10 1 -5 3 1/f CORNER 70Hz CURRENT 0.3 -10 0 1 3 2 TIME (MONTHS) 4 5 1001 G07 0 2 6 4 TIME (SECONDS) 8 10 1001 G08 1 1 10 100 FREQUENCY (Hz) 0.1 1000 1002 G09 1002fb 5 CURRENT NOISE pA/Hz 5 NOISE VOLTAGE 100nV/DIV UW 0 LT10 2AM 100 1002 G04 Distribution of Offset Voltage Drift with Temperature (Individual Amplifiers) 70 60 260 UNITS TESTED 50 25 20 15 10 5 VS = 15V 35 30 Distribution of Offset Voltage Match Drift with Temperature VS = 15V 130 UNITS TESTED 0 -1.2 0 +0.4 +0.8 +1.2 -0.8 -0.4 INPUT OFFSET VOLTAGE DRIFT WITH TEMPERATURE (V/C) 1002 G02 -1.2 0 +0.4 +0.8 +1.2 -0.8 -0.4 OFFSET VOLTAGE MATCH DRIFT WITH TEMPERATURE (V/C) 1002 G03 Offset Voltage Tracking with Temperature of Six Representative Units 5 Warm-Up Drift VS = 15V TA = 25C N14 PLASTIC PACKGE 60 40 20 0 -20 -40 -60 -80 4 LT AM 1002 3 J14 HERMETIC DIP PACKGE 2 L 2M T100 LT1002AM LT1002M 1 125 -100 -50 0 0 3 4 2 TIME AFTER POWER ON - BOTH AMPLIFIERS (MINUTES) 1 5 1002 G06 -25 50 0 75 25 TEMPERATURE (C) 100 125 1002 G04 0.1Hz to 10Hz Noise 100 Noise Spectrum 10 TA = 25C VS = 3 TO 18V LT1002 TYPICAL PERFORMANCE CHARACTERISTICS Matching and Individual Amplifier Bias and Offset Currents vs Temperature 2.0 INPUT BIAS AND OFFSET CURRENTS (nA) 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 INPUT BIAS CURRENT (nA) VCM INVERTING OR NON-INVERTING INPUT BIAS CURRENT (mA) MATCHING: NON INVERTING BIAS CURRENT M N O ATC N -I H I N G N V . : IN V IVI DU OFFS ERING & AL ET C U AM RRENT IND P BI AS C IV I DU URRE AL A NT MP O FFSET CURRENT IN D 0 -50 -25 50 25 75 0 TEMPERATURE (C) Open Loop Voltage Gain vs Temperature 140 OPEN LOOP VOLTAGE GAIN (V/V) 1200k 1000k 800k 600k 400k 200k 0 -50 -25 VS = 15V, VO = 12V VS = 3V, VO = 1V OPEN LOOP VOLTAGE GAIN (dB) 80 60 40 20 0 VOLTAGE GAIN (dB) 100 VS = 15V 12 8 4 0 -4 GAIN 125C GAIN 25C & -55C VS = 15V PHASE MARGIN -55C = 63 125C = 57 0.2 0.5 1 FREQUENCY (MHz) 2 1002 G15 120 25C PHASE MARGIN = 60 140 160 180 200 220 VS = 3V 50 25 75 0 TEMPERATURE (C) 100 125 -20 0.1 1 10 100 1k 10k 100k 1M 10M FREQUENCY (Hz) 1002 G14 -8 0.1 1002 G13 Open Loop Gain Mismatch vs Frequency 1.0 Closed Loop Output Impedance 100 POWER SUPPLY REJECTION (dB) Power Supply Rejection and PSRR Match vs Frequency 160 140 120 100 80 60 40 20 0 0.1 NEGATIVE SUPPLY POSITIVE SUPPLY MATCH (POSITIVE SUPPLY) VS = 15V 2V pp TA = 25C MATCH (NEGATIVE SUPPLY) OPEN LOOP GAIN MISMATCH (PERCENT) VS = 15V TA = 25C OUTPUT IMPEDANCE () 0.8 10 AV = 1000 1 AV = +1 0.1 IO = 1mA VS = 15V TA = 25C 1 10 1k 100 FREQUENCY (Hz) 10k 100k 1002 G17 0.6 0.4 PERCENT GAIN MISMATCH = OUTPUT A - OUTPUT B x 100% 1/2 (OUTPUT A + OUTPUT B) 0.2 0.01 0 1 10 1k 100 FREQUENCY (Hz) 10k 100k 1002 G16 0.001 1 10 100 1k FREQUENCY (Hz) 10k 100k 1002 G18 1002fb 6 PHASE SHIFT (DEGREES) UW VS = 15V 100 1001 G10 Input Bias Current Over the Common Mode Range 1.5 1.0 0.5 0 -.5 DEVICE WITH NEGATIVE INPUT CURRENT -1.0 -1.5 -15 COMMON-MODE INPUT RESISTANCE = 28V = 280G 0.1nA 10 -5 0 5 -10 COMMON-MODE INPUT VOLTAGE 15 Ib Input Bias Current vs. Differential Input Voltage 30 VS = 15V TA = 25C - + DEVICE WITH POSITIVE INPUT CURRENT VS = 15V TA = 25C 20 10 IB 1 nA 0 0.1 0.3 1.0 3.0 10 DIFFERENTIAL INPUT (VOLTS) 30 1002 G12 125 1002 G11 Open Loop Voltage Gain Frequency Response 20 Gain, Phase Shift vs. Frequency 80 PHASE 25C 100 16 120 TA = 25C LT1002 TYPICAL PERFORMANCE CHARACTERISTICS Channel Separation vs Frequency 160 150 CHANNEL SEPARATION (dB) 140 130 120 110 100 RS =1k 90 80 100 1k 100k 10k FREQUENCY (Hz) 1M 1002 G19 COMMON MODE REJECTION (dB) RS =10 120 100 80 60 40 20 0 1 10 CMRR MATCH (< CMRR) COMMON MODE LIMIT (VOLTS) REFERRED TO POWER SUPPLY RS =100 Supply Current vs. Supply Voltage For Each Amplifier OUTPUT VOLTAGE, PEAK-TO-PEAK (VOLTS) 2.0 SUPPLY CURRENT (mA) -55C 1.5 125C 1.0 0.5 3 6 9 12 15 18 21 SUPPLY VOLTAGE (V) 1002 G22 Small Signal Transient Response 100 PERCENT OVERSHOOT AV = +1, CL = 50pF UW VS = 15V TA = 25C Common Mode Rejection and CMRR Match vs Frequency 160 140 VS = 15V TA = 25C V+ -0.2 -0.4 -0.6 -0.8 -1.0 Common Mode Limit vs Temperature V + = 1.2 to 4V V + = 12 to 18V 100 1k 10k FREQUENCY (Hz) 100k 1M +1.0 +.8 +.6 +.4 +.2 V- -50 -25 V - = -12 to -18V V - = -1.2 to -4V 50 25 75 0 TEMPERATURE (C) 100 125 1002 G20 1002 G21 Large Signal Transient Response 28 24 20 16 12 8 4 0 1002 G23 Maximum Undistorted Output vs. Frequency VS = 15V TA = +25C 25C 1 10 100 FREQUENCY (kHz) 1000 1002 G24 Voltage Follower Overshoot vs Capacitive Load VS = 15V TA = 25C VIN = 100mV RL > 50k Small Signal Transient Response 80 60 40 20 0 100 1002 G25 10,000 1000 CAPACITIVE LOAD (PICOFARADS) 100,000 AV = +1, CL = 1000pF 1002 G26 1002 G27 1002fb 7 LT1002 TYPICAL PERFORMANCE CHARACTERISTICS Output Swing vs. Load Resistance 16 SHORT CIRCUIT CURRENT (mA) SINKING SOURCING 50 40 -55C 25C 125C VS = 15V 125C 25C -55C NEGATIVE SWING OUTPUT SWING (VOLTS) 12 8 4 VS = 15V TA = 25C 0 100 300 1000 3k LOAD RESISTANCE () 10k 1002 G28 APPLICATIONS INFORMATION The LT1002 dual amplifier may be inserted directly into OP-10, OP207, OP227 sockets with or without removal of external nulling potentiometers. Offset Voltage Adjustment The input offset voltage of the LT1002, and its drift with temperature, are permanently trimmed at wafer testing to a low level. However, if further adjustment of VOS is necessary, nulling with a 10k or 20k potentiometer will not degrade drift with temperature. Trimming to a value other than zero creates a drift of (VOS/ 300)V/C, e.g. if VOS is adjusted to 300V, the change in drift will be 1V/C. The adjustment range with a 10k or 20k pot is approximately 2.5mV. If less adjustment range is needed, the sensitivity and resolution of the nulling can be improved by using a smaller pot in conjunction with fixed resistors. The example has an approximate null range of 100V. In matching applications, both amplifiers can be trimmed to zero, or the offset of one amplifier can be trimmed to match the offset of the other. Offset adjustment, however, slightly degrades the gain, common-mode and powersupply rejection match between the two op amps. Fortunately, the guaranteed offset voltage match of the LT1002 is very low, in most applications offset adjustment will be unnecessary. Standard Adjustment (10) INPUT 4 (11) Improved Sensitivity Adjustment 1 3 (10) INPUT 4 (11) 8 + - + - U W UW Output Short Circuit Current vs Time 30 20 10 -10 -20 -30 -40 -50 0 POSITIVE SWING 1 3 2 TIME FROM OUTPUT SHORT (MINUTES) 4 1002 G29 U U 10k or 20k 1 (8) 2 3 1/2 LT1002 15V (9) 14 (7) 13 (6) OUTPUT 12 (5) -15V 1002 TA03 7.5k 1k 7.5k (8) 2 (9) 14 (7) 1/2 LT1002 13 (6) 12 (5) -15V 1002 TA04 15V OUTPUT 1002fb LT1002 APPLICATIONS INFORMATION Test Circuit for Offset Voltage and its Drift with Temperature 50k* 15V 10 (10) 100* (11) 50k* 4 12 (5) -15V * RESISTORS MUST HAVE LOW THERMOELECTRIC POTENTIAL. 1002 TA05 VO = 1000 VOS This circuit is also used as burn-in configuration for the LT1002, with supply voltages increased to 20V. Unless proper care is exercised, thermocouple effects, caused by temperature gradients across dissimilar metals at the contacts to the input terminals, can exceed the inherent drift of the amplifier. Air currents should be minimized, package leads should be short, the two input leads should be as close together as possible and maintained at the same temperature. Channel Separation This parameter is defined as the ratio of the change in input offset voltage of one amplifier to the change in output voltage of the other amplifier causing the offset change. At low frequencies the LT1002's channel separation is an almost unmeasurable 148dB. As frequency increases, pin to pin capacitance of the package, between the output of one amplifier and the inputs of the other, becomes dominant. Since these pins are non-adjacent, the capacitance is only 0.02pF. To maintain the LT1002's excellent channel separation at higher frequencies, the socket and PC board capacitances should be minimized. + + - 3 14 (7) 1/2 LT1002 13 (6) VO - U W U U 0.1Hz to 10Hz Noise Test Circuit 0.1F 100k VOLTAGE GAIN = 50,000 PEAK TO PEAK NOISE MEASURED IN 10 SEC INTERVAL A 1/2 LT1002 2k + B 1/2 LT1002 4.3k 22F DEVICE UNDER TEST 4.7F - 100k 24.3k 0.1F 2.2F SCOPE x1 RIN = 1M 110k 1002 TA06 The device under test should be warmed up for three minutes and shielded from air currents. Turn the device 180 to measure the noise of side B. Power supplies The LT1002 is specified over a wide range of power supply voltages from 3V to 18V. Operation with lower supplies is possible, down to 1.2V (two Ni-Cad batteries). However, with 1.2V supplies, the device is stable only in closed loop gains of + 2 or higher (or inverting gain of one or higher). The V+ supply terminals are completely independent and may be powered by separate supplies if desired (this approach, however, would sacrifice the advantages of the power supply rejection ratio matching). The V- supply terminals are both connected to the common substrate and must be tied to the same voltage. Both V - pins should be used. 1002fb 9 LT1002 APPLICATIONS INFORMATION Advantages of Matched Dual Op Amps In many applications the performance of a system depends on the matching between two operational amplifiers rather than the individual characteristics of the two op amps. Two or three op amp instrumentation amplifiers, tracking voltage references and low drift active filters are some of the circuits requiring matching between two op amps. The well-known triple op amp configuration illustrates these concepts. Output offset is a function of the difference between the offsets of the two halves of the LT1002. This error cancellation principle holds for a considerable number of input referred parameters in addition to offset voltage and its drift with temperature. Input bias current will be the average of the two non-inverting input currents (IB+). The difference between these two currents (IOS+) is the offset current of the instrumentation amplifier. The difference between the inverting input currents (IOS-) will cause errors flowing through R1, R2, and R3. Commonmode and power supply rejections will be dependent only on the match between the two amplifiers (assuming perfect resistor matching). The concepts of common mode and power supply rejection ratio match (CMRR and PSRR) are best demonstrated with a numerical example: Assume CMRRA = + 1.0V/V or 120dB, and CMRRB = + 0.75V/V or 122.5dB, then CMRR = 0.25V/V or 132dB; if CMRRB = - 0.75V/V which is still 122.5dB, then CMRR = 1.75V/V or 115dB. Clearly, the LT1002, by specifying and guaranteeing all of these matching parameters, can significantly improve the performance of matching dependent circuits. Three Op Amp Instrumentation Amplifier - 10 U W U U INPUT + A 1/2 LT1002 - R1 10k 1% R3 2.1k 1% R8 200 R4 100 1% R6 10k 1% - R10 100k C1 100pF LT1037 OUTPUT + - INPUT R2 10k 1% R5 100 1% R7 9.76k 1% GAIN = 1000 B 1/2 LT1002 + + R9 200 1002 TA07 Trim R8 for gain Trim R9 for DC common mode rejection Trim R10 for AC common mode rejection Typical performance of the instrumentation amplifier: Input offset voltage = 25V Input bias current = 0.7nA Input resistance = 200 G Input offset current = 0.6nA Input noise = 0.5V p-p Power bandwidth (V0 = 10V) = 80kHz 1002fb LT1002 APPLICATIONS INFORMATION Precision 10V Reference 15V 130k 5% 3.3k 1% 10k 4 + - 3 LM129A 1/2 LT1002 12 8.2k 1% 1k -15V 1002 TA08 The LT1002 contributes less than 5% of the total drift with temperature, noise and long term drift of the reference. Dual Limit Microvolt Comparator 15V 39.2 1% 1k 5% FLV117 15k 1% 13 20k 5% 1/4 CA3118 1/4 CA3118 14 UPPER LIMIT 3 - 1/2 LT1002 4 + 12 -15V INPUT 10 7 - 1/2 LT1002 LOWER LIMIT 11 + 5 -15V When the upper or lower limit is exceeded the LED lights up. Positive feedback to one of the nulling terminals creates 5 to 20V of hysteresis on both amplifiers. This U 14 W U U OUT 1 10.000V 13 10k 0.1% 0.1% 10 - + 7 1/2 LT1002 5 6 OUT 2 -10.000V 11 3.3k 1% The accuracy of the -10V output is limited by the matching of the two 10k resistors. 430k 1% 1 430k 1% 39.2 1% 8 15k 1% 6 1/4 CA3118 1/4 CA3118 1002 TA09 feedback changes the offset voltage of the LT1002 by less than 5V. Therefore, the basic accuracy of the comparator is limited only by the low offset voltage of the LT1002. 1002fb 11 LT1002 APPLICATIONS INFORMATION Two Op Amp Instrumentation Amplifier R5 2.2k R1 100k* R2 10k R4 100k - 1/2 LT1002 - INPUTS + + * TRIM FOR COMMON-MODE REJECTION TRIM FOR GAIN GAIN = R4 1 1+ R3 2 ( R2 R3 R2 + R3 + + 100 R1 R4 R5 Precision Amplifier Drives 500 Load to 10V 1.1Rf + 0.1RS 110k RS 100 RS 100 This application utilizes the guaranteed 10mA load driving capability of the LT1002. The offset voltage of amplifier A is the offset of the configuration. Amplifier B provides the additional 10mA load current. When load resistor RL is 12 U W U U R3 10k - 1/2 LT1002 OUTPUT + 1002 TA10 ) 15V - B 1/2 LT1002 + -15V Rf 100k 0.2RL 100 15V - A 1/2 LT1002 OUTPUT RL 500 1002 TA11 + -15V INPUT removed, amplifier A sinks this current without affecting accuracy. In the gain of 1000 configuration shown, approximately 0.3% gain accuracy can be realized. 1002fb LT1002 APPLICATIONS INFORMATION Dead Zone Generator INPUT Q4 100k** 100k** 2 10k* Q2 6 8 1 3 Q1 2N4393 30pF 4.7k 10k* 2k Q3 VSET DEAD ZONE CONTROL INPUT 0 to 5V BIPOLAR SYMMETRY IS EXCELLENT BECAUSE ONE DEVICE, Q2, SETS BOTH LIMITS - LM301A 3 100k + IN914 15V 100k 15pF 2 4.7k - LM301A 6 4.7k Q5 1k 3 + -15V Precision Absolute Value Circuit 10k 0.1% 10k 0.1% IN4148 13 INPUT -10 to 10V 3 - 1/2 LT1002 4 + IN4148 10k 0.1% U W U U 47pF - 1/2 LT1002 13 10k** 10k** 10 10k 10k Q6 2N4393 - 1/2 LT1002 6 VOUT 4 + 15pF 11 + 3.3k IN914 VSET VOUT VIN VSET * 1% FILM ** RATIO MATCH 0.05% Q2, 3, 4, 5 CA 3096 TRANSISTOR ARRAY 1002 TA12 10k 0.1% 10k 0.1% 10 - 1/2 LT1002 6 OUTPUT 0 to 10V 11 + 1002 TA13 1002fb 13 LT1002 APPLICATIONS INFORMATION 22k* 43k* 100 (SELECT) 3 - 1/2 LT1002 2k 13 IN914 2N2219 OUTPUT 1 0-10V 25mA 15V 4 8.2k + VN-46 LM399 KVD 00000 - 99999 + 1 -15V KELVIN-VARLEY DIVIDER ESI#DP311 VN-46 KVD = ESI#DP311 * = JULIE RSCH. LABS #R-44 25k 680pF 2 - LT301A 6 33k D CLK Q Q 3 + 74C74 33k 15V 33k 15V 1.8k CLAMP SET 5k 14 U W U U 15V 100 5W Dual Precision Power Supply (1) 0 to 10V in 100V Steps (2) 0 to 100V in 1mV Steps TRIAD TY-90 DIODES = SEMTECH # FF-15 + 4 90k* OUTPUT 2 0V-100V, 25mA 0.1F 2.2F + 10k* (SELECT) TRIM-100V 100 2N6533 2k 6 IN914 15 15V 2N2907 IN914 1/2 LT1002 - + 10 + 22F 11 1002 TA14 1002fb LT1002 SCHE ATIC DIAGRA V+ 6k 6k NULL 40k NULL 40k Q5 Q7 Q3 Q6 Q8 Q4 55pF + IN 500 Q1A Q1B Q2B - IN Q10 500 T1 2k 180 1/2 LT1002 V- Q9 Q19 Q20 Q17 Q15 PACKAGE DESCRIPTION J Package 14-Lead CERDIP (Narrow .300 Inch, Hermetic) (Reference LTC DWG # 05-08-1110) 0.785 (19.939) MAX 14 13 12 11 10 9 8 0.300 BSC (0.762 BSC) 0.008 - 0.018 (0.203 - 0.457) 0 - 15 1 0.045 - 0.065 (1.143 - 1.651) 0.100 (2.54) BSC 0.125 (3.175) MIN J14 1298 NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE OR TIN PLATE LEADS Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. U W Q27 Q28 1.5k Q11 Q13 Q14 3k Q31 20pF Q33 20 Q2A 30pF 3k Q21 Q16 Q34 Q26 OUT Q12 25k Q29 Q24 Q25 20 Q22 2k Q23 Q32 Q30 Q18 8k 120 240 1002 SS W 0.200 (5.080) MAX 0.015 - 0.060 (0.381 - 1.524) 0.005 (0.127) MIN 0.025 (0.635) RAD TYP 0.220 - 0.310 (5.588 - 7.874) 2 3 4 5 6 7 0.014 - 0.026 (0.360 - 0.660) OBSOLETE PACKAGE 1002fb 15 LT1002 PACKAGE DESCRIPTION N Package 14-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) 0.770* (19.558) MAX 14 13 12 11 10 9 8 0.300 - 0.325 (7.620 - 8.255) 0.009 - 0.015 (0.229 - 0.381) 0.005 (0.125) MIN 0.100 (2.54) *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. BSC MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm) +0.035 0.325 -0.015 +0.889 8.255 -0.381 ( ) RELATED PARTS PART NUMBER LT1001 LT1884/LT1885 DESCRIPTION Single LT1002 Dual/Quad Precision Op Amp with Rail-to-Rail Output COMMENTS 60V VOS, 1V/C Precision Op Amp 50V Max VOS, 400pA Max IB 16 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 q FAX: (408) 434-0507 q U 0.255 0.015* (6.477 0.381) 1 0.130 0.005 (3.302 0.127) 0.020 (0.508) MIN 2 3 4 5 6 7 0.045 - 0.065 (1.143 - 1.651) 0.065 (1.651) TYP 0.125 (3.175) MIN 0.018 0.003 (0.457 0.076) N14 1098 1002fb LT/CPI 1101 1.5K REV B * PRINTED IN USA www.linear.com (c) LINEAR TECHNOLOGY CORPORATION 1985 |
Price & Availability of LT1002A |
|
|
All Rights Reserved © IC-ON-LINE 2003 - 2022 |
[Add Bookmark] [Contact Us] [Link exchange] [Privacy policy] |
Mirror Sites : [www.datasheet.hk]
[www.maxim4u.com] [www.ic-on-line.cn]
[www.ic-on-line.com] [www.ic-on-line.net]
[www.alldatasheet.com.cn]
[www.gdcy.com]
[www.gdcy.net] |