LT1097 Low Cost, Low Power Precision Op Amp U DESCRIPTION FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Offset Voltage 50µV Max Offset Voltage Drift 1µV/°C Max Bias Current 250pA Max Offset Current 250pA Max Bias and Offset Current Drift 4pA/°C Max Supply Current 560µA Max 0.1Hz to 10Hz Noise 0.5µVp-p, 2.2pAp-p CMRR 115dB Min Voltage Gain 117dB Min PSRR 114dB Min Guaranteed Operation on Two NiCad Batteries U APPLICATIONS ■ ■ ■ ■ ■ ■ Replaces OP-07/OP-77/OP-97/OP-177/AD707/ LT1001 with Improved Price/Performance High Impedance Difference Amplifiers Logarithmic Amplifiers (Wide Dynamic Range) Thermocouple Amplifiers Precision Instrumentation Active Filters (with Small Capacitors) LT®1097 achieves a new standard in combining low price and outstanding precision performance. On all operational amplifier data sheets, the specifications listed on the front page are for highly selected, expensive grades, while the specs for the low cost grades are buried deep in the data sheet. The LT1097 does not have any selected grades, the outstanding specifications shown in the Features section are for its only grade. The design effort of the LT1097 concentrated on optimizing the performance of all precision specs—at only 350µA of supply current. Typical values are 10µV offset voltage, 40pA bias and offset currents, 0.2µV/°C and 0.4pA/°C drift. Common mode and power supply rejections, voltage gain are typically in excess of 128dB. All parameters that are important for precision, low power op amps have been optimized. Consequently, using the LT1097 error budget calculations in most applications is unnecessary. , LTC and LT are registered trademarks of Linear Technology Corporation. U TYPICAL APPLICATION Input Offset Voltage Distribution Saturated Standard Cell Amplifier 9V 50 2N3609 + 7 LT1097 2 + 1.018235V SATURATED STANDARD CELL #101 EPPLEY LABS NEWPORT, R. I. R1 20k – 40 6 OUT = 1.1V TO 8.0V AS 1.8k ≤ R2 ≤ 135k 4 PERCENT OF UNITS 3 30 6,500 UNITS IN SO PACKAGE 6,680 UNITS IN PLASTIC VS = ±15V DIP TA = 25°C 13,180 UNITS TESTED 20 10 R2 THE TYPICAL 40pA BIAS CURRENT OF THE LT1097 WILL DEGRADE THE STANDARD CELL BY ONLY 1ppm/YEAR. NOISE IS A FRACTION OF A ppm. UNPROTECTED GATE MOSFET ISOLATES STANDARD CELL ON POWER DOWN. 0 –50 –40 –30 –20 –10 0 10 20 30 40 50 INPUT OFFSET VOLTAGE (µV) LT1097 • G01 LT1097•TA01 1 LT1097 U W W W ABSOLUTE MAXIMUM RATINGS Supply Voltage ...................................................... ±20V Differential Input Current (Note 1) ...................... ±10mA Input Voltage ......................................................... ±20V Output Short Circuit Duration .......................... Indefinite Operating Temperature Range .................–40°C to 85°C Storage Temperature Range ..................–65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C U W U PACKAGE/ORDER INFORMATION TOP VIEW VOS TRIM 1 8 VOS TRIM –IN 2 7 V+ +IN 3 6 OUT V– 4 5 OVER COMP ORDER PART NUMBER LT1097CN8 TOP VIEW VOS TRIM 1 8 VOS TRIM –IN 2 7 V+ +IN 3 6 OUT V– 4 5 OVER COMP N8 PACKAGE 8-LEAD PLASTIC DIP LT1097S8 S8 PACKAGE 8-LEAD PLASTIC SO ELECTRICAL CHARACTERISTICS VS = ±15V, VCM = 0V, TA = 25°C, unless otherwise noted. CONDITIONS MIN LT1097CN8 TYP MAX SYMBOL PARAMETER VOS Input Offset Voltage 10 Long Term Input Offset Voltage Stability 0.3 ∆VOS ∆TIME ORDER PART NUMBER MIN 50 LT1097S8 TYP MAX 10 60 UNITS µV µV/Mo 0.3 IOS Input Offset Current 40 250 60 350 pA IB Input Bias Current ±40 ±250 ±50 ±350 pA en Input Noise Voltage 0.1Hz to 10Hz 0.5 0.5 µVp-p Input Noise Voltage Density fO = 10Hz fO = 1000Hz 16 14 16 14 nV/√Hz nV/√Hz Input Noise Current 0.1Hz to 10Hz 2.2 2.4 pAp-p Input Noise Current Density fO = 10Hz fO = 1000Hz 0.03 0.008 0.035 0.008 pA/√Hz pA/√Hz Input Resistance Differential Mode Common Mode (Note 2) in Input Voltage Range CMRR Common Mode Rejection Ratio VCM = ±13.5V 30 80 1012 25 70 8•1011 MΩ Ω ±13.5 ±14.3 ±13.5 ±14.3 V 115 130 115 130 dB PSRR Power Supply Rejection Ratio VS = ±1.2V to ±20V 114 130 114 130 dB AVOL Large Signal Voltage Gain VO = ±12V, RL = 10k VO = ±10V, RL = 2k 700 250 2500 1000 700 250 2500 1000 V/mV V/mV VOUT Output Voltage Swing RL = 10k RL = 2k ±13 ±11.5 ±13.8 ±13 ±13 ±11.5 ±13.8 ±13 V V SR Slew Rate 0.1 0.2 0.1 0.2 V/µs GBW Gain Bandwidth Product 700 kHz IS Supply Current 2 700 350 Offset Adjustment Range RPOT = 10k, Wiper to V+ Minimum Supply Voltage (Note 3) 560 350 ±600 ±1.2 — ±1.2 560 µA ±600 µV — V LT1097 ELECTRICAL CHARACTERISTICS VS = ±15V, VCM = 0V, 0°C ≤ TA ≤ 70°C, unless otherwise noted. LT1097S8 TYP MAX UNITS 100 20 130 µV 0.2 1 0.2 1.4 µV/°C ● 60 430 75 570 pA Average Temperature Coefficient of (Note 4) Input Offset Current ● 0.4 4 0.5 5 Input Bias Current ● ±60 ±430 ±75 ±570 Average Temperature Coefficient of (Note 4) Input Bias Current ● 0.4 4 0.5 5 PARAMETER VOS Input Offset Voltage ● 20 Average Temperature Coefficient of (Note 4) Input Offset Voltage ● Input Offset Current IOS IB CONDITIONS MIN LT1097CN8 TYP MAX SYMBOL MIN pA/°C pA pA/°C AVOL Large Signal Voltage Gain VOUT = ±12V, RL ≥ 10k VOUT = ±10V, RL ≥ 2k ● ● 450 180 2000 800 450 180 2000 800 V/mV V/mV CMRR Common Mode Rejection Ratio VCM = ±13.5V ● 112 128 112 128 dB PSRR Power Supply Rejection Ratio VS = ±1.3V to ±20V ● 111 128 111 128 dB ● ±13.5 ±14.2 ±13.5 ±14.2 V ● ±13 ±13.7 ±13 ±13.7 Input Voltage Range VOUT Output Voltage Swing IS Supply Current RL = 10k 380 ● ELECTRICAL CHARACTERISTICS V 700 µA LT1097S8 TYP MAX UNITS 130 30 170 µV 0.3 1.2 0.3 1.6 µV/°C ● 70 600 85 750 pA Average Temperature Coefficient of Input Offset Current ● 0.5 5 0.6 6 Input Bias Current ● ±70 ±600 ±85 ±750 Average Temperature Coefficient of Input Bias Current ● 0.5 5 0.6 6 CONDITIONS MIN LT1097CN8 TYP MAX PARAMETER VOS Input Offset Voltage ● 25 Average Temperature Coefficient of Input Offset Voltage ● Input Offset Current IB 380 VS = ±15V, VCM = 0V, –40°C ≤ TA ≤ 85°C, unless otherwise noted. (Note 5) SYMBOL IOS 700 MIN pA/°C pA pA/°C AVOL Large Signal Voltage Gain VOUT = ±12V, RL ≥ 10k VOUT = ±10V, RL ≥ 2k ● ● 300 1700 700 300 1700 700 V/mV V/mV CMRR Common Mode Rejection Ratio VCM = ±13.5V ● 108 127 108 127 dB PSRR Power Supply Rejection Ratio VS = ±1.5V to ±20V ● 108 127 108 127 dB ● ±13.5 ±14 ±13.5 ±14 V ● ±13 ±13.6 ±13 ±13.6 Input Voltage Range VOUT Output Voltage Swing IS Supply Current RL = 10k The ● denotes specifications which apply over the full operating temperature range. Note 1: Differential input voltages greater than 1V will cause excessive current to flow through the input protection diodes unless limiting resistance is used. Note 2: This parameter is guaranteed by design and is not tested. ● 400 800 400 V 800 µA Note 3: Power supply rejection ratio is measured at the minimum supply voltage. Note 4: This parameter is not 100% tested. Note 5: The LT1097 is designed, characterized and expected to meet these extended temperature limits, but is not tested at –40°C and 85°C. Guaranteed I grade parts are available; consult factory. 3 LT1097 U W TYPICAL PERFORMANCE CHARACTERISTICS Distribution to Offset Voltage Drift with Temperature 50 VS = ±15V 240 UNITS TESTED IN N8 PACKAGES FROM SIX RUNS PERCENT OF UNITS 40 30 20 10 0 –1.5 –1.2 –0.9 –0.6 –0.3 0 0.3 0.6 0.9 1.2 1.5 OFFSET VOLTAGE DRIFT WITH TEMPERATURE (µV/°C) LT1097 • G02 Minimum Supply Voltage, Common Mode Range and Voltage Swing at VMIN INPUT BIAS CURRENT (pA) 200 100 UNDERCANCELLED UNIT 0 –100 OVERCANCELLED UNIT –200 –300 –50 –25 0 25 50 TEMPERATURE (°C) 75 V+ ±1.4 V+ –0.2 ±1.2 V+ –0.4 V+ –0.6 ±1.0 CM RANGE ±0.8 V+ –0.8 SWING V– +0.8 SWING RL = 10k V– +0.6 CM RANGE V– +0.4 V– +0.2 100 V– –40 –10 20 50 TEMPERATURE (°C) 80 1097 • G03 Input Bias Current Over Common Mode Range 120 VS = ±15V TA = 25°C 80 INPUT BIAS CURRENT (pA) CHANGE IN OFFSET VOLTAGE (µV) 5 3 2 PLASTIC-IN-LINE PACKAGE PLASTIC (N) OR SO (S) 1 0 1 2 3 4 TIME AFTER POWER ON (MINUTES) 5 1097 • G05 4 VS = ±15V TA = 25°C DEVICE WITH POSITIVE INPUT CURRENT 40 RIN CM = 1012Ω 0 DEVICE WITH NEGATIVE INPUT CURRENT –40 – –80 0 110 1097 • G04 Warm-Up Drift 4 MINIMUM SUPPLY VOLTAGE, VMIN (V) COMMON MODE RANGE OR OUTPUT SWING (V) Input Bias Current vs Temperature –120 –15 VCM IB + –10 –5 0 5 10 COMMON MODE INPUT VOLTAGE 15 1097 • G06 LT1097 U W TYPICAL PERFORMANCE CHARACTERISTICS Output Short Circuit Current vs Time SHORT CIRCUIT CURRENT (mA) SINKING SOURCING 20 15 10 5 VS = ±15V TA = 25°C 0 –5 –10 –15 –20 0 1 2 TIME FROM OUTPUT SHORT (MINUTES) 3 1097 • G07 0.1Hz to 10Hz Noise 0.01Hz to 10Hz Noise 0 2 4 6 TIME (SECONDS) 8 VS = ±1.2V TO ±20V TA = 25°C 0.4µV NOISE VOLTAGE (0.4µV/DIV) NOISE VOLTAGE (0.4µV/DIV) VS = ±1.2V TO ±20V TA = 25°C 10 0 20 40 60 TIME (SECONDS) 80 1097 • G08 1097 • G09 Voltage Gain Noise Spectrum 1000 –30 TA = 25°C VS = ±1.2V TO ±20V 100 CURRENT NOISE VOLTAGE NOISE 10 1/f CORNER 2.5Hz 1/f CORNER 140Hz 1 1 10 100 FREQUENCY (Hz) 1000 1097 • G10 CHANGE IN OFFSET VOLTAGE (µV) VOLTAGE NOISE DENSITY (nV√Hz) CURRENT NOISE DENSITY (fA√Hz) 100 –20 Vs = ±15 V TA = 25°C –10 RL = 10k 0 10 RL = 10k RL = 2k RL = 2k 20 30 –15 –10 –5 0 5 OUTPUT VOLTAGE (V) 10 15 1097 • G11 5 LT1097 U W TYPICAL PERFORMANCE CHARACTERISTICS Voltage Gain vs Frequency 140 VS = ±15V TA = 25°C 120 VOLTAGE GAIN (dB) 100 80 60 40 20 0 –20 0.01 0.1 1 10 100 1k 10k 100k 1M 10M FREQUENCY (Hz) 1097 • G12 Common Mode Rejection vs Frequency Gain, Phase Shift vs Frequency PHASE 120 GAIN (dB) GAIN 20 140 10 160 0 180 PHASE MARGIN = 70°C 0.1 1 FREQUENCY (MHz) 10 PHASE SHIFT (DEGREES) 30 –10 0.01 140 100 VS = ±15V TA = 25°C COMMON MODE REJCTION RATIO (dB) 40 VS = ±15V TA = 25°C 120 100 80 60 40 20 0 200 1 10 100 1k 10k FREQUENCY (Hz) 100k 1097 • G13 1097 • G14 Slew Rate, Gain Bandwidth Product vs Overcompensation Capacitor Power Supply Rejection vs Frequency 1 SLEW RATE (V/µs) 120 100 NEGATIVE SUPPLY 80 POSITIVE SUPPLY 60 SLEW 0.1 GBW 0.01 100 10 40 VS = ±15V TA = 25°C 0.001 1 10 100 1k 10k 100k FREQUENCY (Hz) 1M 1097 • G15 6 1000 VS = ±15V TA = 25°C 1 1 10 100 1000 10000 OVERCOMPENSATION CAPACITOR (pF) 1097 • G16 GAIN BANDWIDTH PRODUCT (kHz) POWER SUPPLY REJECTION RATIO (dB) 140 20 0.1 1M LT1097 U W TYPICAL PERFORMANCE CHARACTERISTICS Large Signal Transient Response 2V/DIV 20mV/DIV Small Signal Transient Response AV = 1, CLOAD = 100pF, 5µs/DIV 1097 G17 AV = 1, 20µs/DIV 1097 G18 Capacitive Load Handling 70 TA = 25°C VS = ±15V CS: PIN 5 TO GROUND 60 OVERSHOOT (%) 50 AV = 1 CS = 0 40 30 AV = 1 CS = 200pF 20 10 AV = 10 CS = 0 0 10 100 1000 CAPACITIVE LOAD (pF) 10,000 1097 G19 7 LT1097 W W SCHEMATIC DIAGRAM TRIM 1 TRIM 8 V+ 5 OVER COMP 7 800Ω 800Ω 30k 30k 20µA 35µA 80µA 1.3k 30pF Q19 Q22 1.5k 2.5k 1.5k Q33 Q25 Q21 Q27 Q6 Q5 Q29 S Q8 Q24 Q4 40Ω Q7 – IN S S Q1 2 Q2 100Ω 3k Q13 S OUT 6 Q11 Q23 1.5k 40Ω Q3 Q20 50k Q28 J1 1.5k Q26 Q9 Q32 Q18 Q12 Q16 +IN Q10 Q17 3 3.7k 15µA 80µA Q30 5µA Q31 Q14 Q15 5µA 3.7k 3.7k 16k 40Ω 330Ω V– 4 Q1–Q4 ARE SUPERGAIN TRANSISTORS 8 1097 BD LT1097 U U W U APPLICATIONS INFORMATION The LT1097 is pin compatible to and directly replaces such precision op amps as the OP-07, OP-77, AD707, OP-97, OP177, LM607 and LT1001 with improved price/performance. Compatibility includes externally nulling the offset voltage, as all of the above devices are trimmed with a potentiometer between Pin 1 and Pin 8 and the wiper tied to V+. The simple difference amplifier can be used to illustrate the all-around excellence of the LT1097. The 50k input resistance is selected to be large enough compared to input signal source resistance. Simultaneously, the 50k resistors should not dominate the precision and noise error budget. Assuming perfect matching between the four resistors, the following table summarizes the input ±27V Common Mode Range Difference Amplifier referred performance obtained using the LT1097 and other popular, low cost precision op amps. Input offset voltage can be adjusted over a ±600µV range with a 10k potentiometer. The LT1097 is internally compensated for unity gain stability. As shown on the Capacitive Load Handling plot, the LT1097 is stable with any capacitive load. However, the overcompensation capacitor, CS, can be used to reduce overshoot with heavy capacitive loads, to narrow noise bandwidth or to stabilize circuits with gain in the feedback loop. Frequency Compensation and Optional Offset Nulling 50k 15V 50k –IN 50k +IN 2 – 3 50k + 1 2 7 LT1097 V+ 10k POT 6 – 8 LT1097 OUT 3 4 + 4 –15V 7 6 OUT 5 CS V– LT1097•F02 LT1097•F01 Guaranteed Perfomance, VS = ±15V, TA = 25°C PARAMETER LT1097CN8 OP-77GP AD707JN OP-177GP OP-97FP Error Terms VOS Max IOS Max•25k Gain Min, 10V Out CMRR, Min, ±25V In PSRR, Min, VS = ±15V ±10% UNITS 50 6 14 22 6 100 70 5 20 9 90 50 3 13 9 60 70 5 22 9 75 4 50 39 9 µV µV µV µV µV Sum of All Error Terms 98 204 165 166 177 µV 0.1Hz to 10Hz Noise Voltage Noise Current Noise•50k Resistor Noise 0.5 0.11 0.55 0.38 0.75 0.55 0.23 0.7 0.55 0.38 0.75 0.55 0.5 0.1 0.55 µVp-p Typ µVp-p Typ µVp-p Typ RMS sum 0.75 1 0.92 1 0.75 µVp-p Drift with Temp TCVOS Max TCIOS Max•25k 1 0.1 1.2 2.1 1 1 1.2 2.1 2 0.2 µV/°C µV/°C Sum of Drift Terms 1.1 3.3 2 3.3 2.2 µV/°C Supply Current Max 0.56 2 3 2 0.6 mA 9 LT1097 U U W U APPLICATIONS INFORMATION The availability of the compensation terminal permits the use of feedforward frequency compensation to enhance slew rate. The voltage follower feedforward scheme bypasses the amplifier’s gain stages and slews at nearly 10V/µs. The inputs of the LT1097 are protected with back-to-back diodes. In the voltage follower configuration, when the input is driven by a fast, large signal pulse (>1V), the input Follower Feedforward Compensation protection diodes effectively short the output to the input during slewing, and a current, limited only by the output short circuit protection will flow through the diodes. The use of a feedback resistor, as shown in the voltage follower feedforward diagram, is recommended because this resistor keeps the current below the short circuit limit, resulting in faster recovery and settling of the output. Pulse Response of Feedforward Compensation Test Circuit for Offset Voltage and its Drift with Temperature 50pF 50k* 15V 10k 5k IN 5V/DIV 2 – LT1097 3 2 + 6 100Ω* OUT 5 50k* 1097 G20 5µs/DIV 7 LT1097 3 0.01µF + 6 VO 4 –15V VO = 1000VOS *RESISTORS MUST HAVE LOW THERMOELECTRIC POTENTIAL LT1097•F03 U TYPICAL APPLICATIO Low Power Comparator with <10µV Hysteresis 5V 330k 7 10k +IN 10k –IN 2 1 LT1097 3 + 1k 100k OUT – 620k 6 2N3904 100k 4 –5V 10 – LT1097•TA02 LT1097•F04 LT1097 U PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. N8 Package 8-Lead PDIP (Narrow 0.300) (LTC DWG # 05-08-1510) 0.400* (10.160) MAX 8 7 6 5 1 2 3 4 0.255 ± 0.015* (6.477 ± 0.381) 0.300 – 0.325 (7.620 – 8.255) 0.065 (1.651) TYP 0.009 – 0.015 (0.229 – 0.381) ( +0.035 0.325 –0.015 8.255 +0.889 –0.381 0.130 ± 0.005 (3.302 ± 0.127) 0.045 – 0.065 (1.143 – 1.651) ) 0.125 (3.175) 0.020 MIN (0.508) MIN 0.018 ± 0.003 (0.457 ± 0.076) N8 1197 0.100 ± 0.010 (2.540 ± 0.254) *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm) S8 Package 8-Lead Plastic Small Outline (Narrow 0.150) (LTC DWG # 05-08-1610) 0.189 – 0.197* (4.801 – 5.004) 8 7 5 6 0.150 – 0.157** (3.810 – 3.988) 0.228 – 0.244 (5.791 – 6.197) 1 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0.053 – 0.069 (1.346 – 1.752) 2 3 4 0.004 – 0.010 (0.101 – 0.254) 0°– 8° TYP 0.016 – 0.050 0.406 – 1.270 0.014 – 0.019 (0.355 – 0.483) *DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE **DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE 0.050 (1.270) TYP 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. SO8 0996 11 LT1097 U TYPICAL APPLICATIO Input Amplifier for 4 1/2 Digit Voltmeter 0.1V 15V IN 2 0.1V 100k 5% 1V – 7 3 4 + 5 9M 10V 1V 6 LT1097 9k* 10V 1k* 1000V 100V –5V 1000pF 900k 100V *RATIO MATCH ±0.01% TO 1V FULL SCALE ANALOG DIGITAL CONVERTER 90k 1000V FN507 10k ALLEN BRADLEY DECADE VOLTAGE DIVIDER THIS APPLICATION REQUIRES LOW BIAS CURRENT AND OFFSET VOLTAGE, LOW NOISE, AND LOW DRIFT WITH TIME AND TEMPERATURE. LT1097•TA03 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1490/LT1491 Dual/Quad General Purpose Micropower Rail-to-Rail Op Amps Over-The-TopTM Inputs, 50µA Supply Current Per Amplifier, 2V to 44V Supply Range, 180kHz GBW LT1492/LT1493 Dual/Quad 5MHz Low Power Single Supply Op Amps 180µV VOS Max, 3V/µs Slew Rate, 550µA Supply Per Amplifier LT1077 Single Micropower Low VOS Op Amp 60µV VOS Max, 68µA Supply Current, 230kHz GBW, Optimized for 5V Supplies Over-The-Top is a trademark of Linear Technology Corporation. 12 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417● (408) 432-1900 FAX: (408) 434-0507● TELEX: 499-3977 ● www.linear-tech.com 1097fas sn1097 LT/TP 0398 2K REV A • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 1989