LT1112CN8

LT1112/LT1114 Dual/Quad Low Power Precision, Picoamp Input Op Amps FEATURES s s s DESCRIPTIO s s s s s s s s s S8 Package – Standard Pinout Offset Voltage – Prime Grade: 60µV Max Offset Voltage – Low Cost Grade (Including Surface Mount Dual/Quad): 75µV Max Offset Voltage Drift: 0.5µV/°C Max Input Bias Current: 250pA Max 0.1Hz to 10Hz Noise: 0.3µVP-P, 2.2pAP-P Supply Current per Amplifier: 400µA Max CMRR: 120dB Min Voltage Gain: 1 Million Min Guaranteed Specs with ± 1.0V Supplies Guaranteed Matching Specifications LT1114 in Narrow Surface Mount Package The LT1112 dual and LT1114 quad op amps achieve a new standard in combining low cost and outstanding precision specifications. The performance of the selected prime grades matches or exceeds competitive devices. In the design of the LT1112/ LT1114 however, particular emphasis has been placed on optimizing performance in the low cost plastic and SO packages. For example, the 75µV maximum offset voltage in these low cost packages is the lowest on any dual or quad non-chopper op amp. The LT1112/LT1114 also provide a full set of matching specifications, facilitating their use in such matching dependent applications as two and three op amp instrumentation amplifiers. Another set of specifications is furnished at ± 1V supplies. This, combined with the low 320µA supply current per amplifier, allows the LT1112/LT1114 to be powered by two nearly discharged AA cells. Protected by U.S. Patents 4,575,685; 4,775,884 and 4,837,496 APPLICATI s s s s s s S Picoampere/Microvolt Instrumentation Two and Three Op Amp Instrumentation Amplifers Thermocouple and Bridge Amplifiers Low Frequency Active Filters Photo Current Amplifiers Battery-Powered Systems Dual Output, Buffered Reference (On Single 3V Supply) TOTAL SUPPLY CURRENT = 700µA 2V REFERENCE: SOURCES 1.7mA, SINKS 5mA RX OPTIONAL RX = 300Ω INCREASES SOURCE CURRENT TO 5mA 0.765V REFERENCE: SOURCES 5mA, SINKS 0.5mA TEMPERATURE COEFFICIENT LIMITED BY REFERENCE = 20ppm/°C 2.000V MINIMUM SUPPLY = 2.7V 3V 30 25 15k PERCENT OF UNITS 75k 0.1% LT1004-1.2 46.4k 0.1% + 5 – 6 + 3 – 2 8 1 20 15 10 5 1/2 LT1112 1/2 LT1112 4 7 0.765V 0 –70 –50 LT1112/14 • TA01 U Distribution of Input Offset Voltage (In All Packages) VS = ±15V TA = 25°C 50 30 –30 –10 10 INPUT OFFSET VOLTAGE (µV) 70 LT1112/14 • TA02 UO 1 LT1112/LT1114 ABSOLUTE AXI U RATI GS Operating Temperature Range LT1112AM/LT1112M LT1114AM/LT1114M ...................... – 55°C to 125°C LT1112AC/LT1112C/LT1112S8 LT1114AC/LT1114C/LT1114S .......... – 40°C to 85°C Supply Voltage ..................................................... ± 20V Differential Input Current (Note 1) ..................... ±10mA Input Voltage (Equal to Supply Voltage) ............... ± 20V Output Short-Circuit Duration ......................... Indefinite Storage Temperature Range ................ – 65°C to 150°C Lead Temperature (Soldering, 10 sec)................ 300°C PACKAGE/ORDER I FOR ATIO TOP VIEW OUT A 1 –IN A 2 +IN A 3 V– 4 J8 PACKAGE 8-LEAD CERAMIC DIP B 5 +IN B A 8 7 6 V + ORDER PART NUMBER LT1112AMJ8 LT1112MJ8 LT1112ACN8 LT1112CN8 OUT B –IN B N8 PACKAGE 8-LEAD PLASTIC DIP TJMAX = 160°C, θJA = 100°C/W (J8) TJMAX = 140°C, θJA = 130°C/W (N8) TOP VIEW OUT A –IN A +IN A V+ +IN B –IN B OUT B 1 2 3 4 5 6 7 B C A D 14 OUT D 13 –IN D 12 +IN D 11 V – 10 +IN C 9 8 –IN C OUT C ORDER PART NUMBER LT1114AMJ LT1114MJ LT1114ACN LT1114CN J PACKAGE N PACKAGE 14-LEAD CERAMIC DIP 14-LEAD PLASTIC DIP TJMAX = 160°C, θJA = 80°C/W (J) TJMAX = 140°C, θJA = 110°C/W (N) ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER VOS ∆VOS ∆Time IOS IB en Input Offset Voltage Long Term Input Offset Voltage Stability Input Offset Current LT1114S Input Bias Current LT1114S Input Noise Voltage VS = ±15V, VCM = 0V, TA = 25°C, unless otherwise noted. LT1112AM/AC LT1114AM/AC MIN TYP MAX 20 40 0.3 50 ± 70 180 ± 250 0.9 60 110 CONDITIONS (Note 2) VS = ± 1.0V 0.1Hz to 10Hz (Note 9) 2 U U W WW U W TOP VIEW OUT A 1 –IN A 2 +IN A 3 V– 4 B 5 +IN B A 8 7 6 V+ OUT B –IN B ORDER PART NUMBER LT1112S8 PART MARKING 1112 ORDER PART NUMBER LT1114S S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 140° C, θJA = 190°C/W TOP VIEW OUT A 1 –IN A 2 +IN A 3 V+ 4 +IN B 5 –IN B 6 OUT B 7 NC 8 B C A D 16 OUT D 15 –IN D 14 +IN D 13 V – 12 +IN C 11 –IN C 10 OUT C 9 NC S PACKAGE 16-LEAD PLASTIC SO (NARROW) TJMAX = 140°C, θJA = 150°C/W LT1112M/C/S8 LT1114M/C/S MIN TYP MAX 25 45 0.3 60 75 ± 80 ± 100 0.3 230 330 ± 280 ± 450 0.9 75 130 UNITS µV µV µV/Mo pA pA pA pA µVP-P 0.3 LT1112/LT1114 ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER Input Noise Voltage Density in Input Noise Current Input Noise Current Density VCM CMRR PSRR RIN Input Voltage Range Common-Mode Rejection Ratio Power Supply Rejection Ratio Minimum Supply Voltage Input Resistance Differential Mode Common Mode Large-Signal Voltage Gain Output Voltage Swing Slew Rate Gain-Bandwidth Product Supply Current per Amplifier VS = ±1.0V Channel Separation ∆VOS ∆ IB + VS = ±15V, VCM = 0V, TA = 25°C, unless otherwise noted. LT1112AM/AC LT1114AM/AC MIN TYP MAX 16 14 2.2 0.030 0.008 ± 13.5 ± 14.3 136 126 ± 13.5 115 114 ± 1.0 50 800 5000 1500 ± 14.0 ± 12.4 0.30 750 350 320 150 35 100 100 450 113 112 400 370 15 800 600 ± 13.0 ± 11.0 0.16 450 40 700 5000 1300 ± 14.0 ± 12.4 0.30 750 350 320 150 40 100 120 136 130 130 500 680 450 420 120 116 ± 1.0 20 1000 800 ± 13.0 ± 11.0 0.16 450 28 18 CONDITIONS (Note 2) fO = 10Hz (Note 9) fO = 1000Hz (Note 9) 0.1Hz to 10Hz fO = 10Hz fO = 1000Hz VCM = ± 13.5V VS = ±1.0V to ± 20V (Note 4) (Note 3) VO = ±12V, RL = 10kΩ VO = ±10V, RL = 2kΩ RL = 10kΩ RL = 2kΩ fO = 10kHz LT1112M/C/S8 LT1114M/C/S MIN TYP MAX 16 14 2.2 0.030 0.008 ± 14.3 136 126 28 18 UNITS nV/√Hz nV/√Hz pAP-P pA/√Hz pA/√Hz V dB dB V MΩ GΩ V/mV V/mV V V V/µs kHz µA µA dB µV pA pA dB dB AVOL VOUT SR GBW IS fO = 10Hz (Note 5) LT1114S (Notes 5, 7) (Notes 5, 7) 117 114 Offset Voltage Match Noninverting Bias Current Match (Notes 5, 6) Common-Mode Rejection Match Power Supply Rejection Match ∆CMRR ∆PSRR 136 130 ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER VOS ∆VOS ∆Temp IOS IB VCM CMRR PSRR AVOL Input Offset Voltage Average Input Offset Voltage Drift Input Offset Current Input Bias Current Input Voltage Range Common-Mode Rejection Ratio Power Supply Rejection Ratio Large-Signal Voltage Gain VCM = ± 13.5V VS = ± 1.2V to ± 20V VS = ±15V, – 55°C ≤ TA ≤ 125°C, unless otherwise noted. LT1112AMJ8 LT1114AMJ MIN TYP MAX q q q q q q q q q q CONDITIONS (Note 2) VS = ±1.2V (Note 8) LT1112MJ8 LT1114MJ MIN TYP MAX 45 70 0.20 100 ± 170 ± 13.5 111 110 400 170 ± 14.1 130 124 2500 500 150 260 0.75 500 ± 700 UNITS µV µV µV/°C pA pA V dB dB V/mV V/mV 35 60 0.15 80 ± 150 ± 13.5 116 112 500 200 ± 14.1 130 124 2500 600 120 220 0.5 400 ± 600 VO = ± 12V, RL = 10kΩ VO = ± 10V, RL = 2kΩ 3 LT1112/LT1114 ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER VOUT SR IS ∆VOS ∆IB+ ∆CMRR ∆PSRR Output Voltage Swing Slew Rate Supply Current per Amplifier Offset Voltage Match Offset Voltage Match Drift Noninverting Bias Current Match Common-Mode Rejection Ratio Power Supply Rejection Ratio (Note 5) (Notes 5, 8) (Notes 5, 6) (Notes 5, 7) (Notes 5, 7) RL = 10kΩ VS = ±15V, – 55°C ≤ TA ≤ 125°C, unless otherwise noted. LT1112AMJ8 LT1114AMJ MIN TYP MAX q q q q q q q q CONDITIONS (Note 2) LT1112MJ8 LT1114MJ MIN TYP MAX ± 13.0 ± 13.85 0.12 0.22 380 70 0.3 170 106 106 130 126 530 240 1.0 850 UNITS V V/µs µA µV µV/°C pA dB dB ± 13.0 ± 13.85 0.12 0.22 380 55 0.2 150 112 109 130 126 460 200 0.7 750 ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER VOS ∆VOS ∆Temp IOS IB VCM CMRR PSRR AVOL VOUT SR IS ∆VOS Input Offset Voltage VS = ±15V, 0°C ≤ TA ≤ 70°C, unless otherwise noted. LT1112ACN8 LT1114ACN MIN TYP MAX q q q q q q q q q q CONDITIONS (Note 2) LT1112N8 LT1112S8, LT1114N/S VS = ± 1.2V LT1112N8 LT1112S8, LT1114N/S LT1114S LT1112N8/S8 LT1114CN/S MIN TYP MAX 30 45 65 0.2 0.4 70 90 ± 90 ± 115 ± 13.5 113 112 650 400 ± 13.0 0.14 ± 14.2 133 125 4000 1000 ± 13.9 0.27 370 55 70 0.3 0.5 135 160 109 108 134 128 500 210 270 1.0 1.9 620 880 125 150 210 0.75 1.3 290 420 ± 350 ± 550 UNITS µV µV µV µV/°C µV/°C pA pA pA pA V dB dB V/mV V/mV V V/µs µA µV µV µV/°C µV/°C pA pA dB dB 27 35 50 0.15 0.3 60 ± 80 ± 13.5 118 114 800 500 ± 13.0 0.14 ± 14.2 133 125 4000 1300 ± 13.9 0.27 370 45 55 0.2 0.4 120 114 110 134 128 100 125 175 0.5 1.1 220 ± 300 Average Input Offset Voltage Drift (Note 8) Input Offset Current Input Bias Current LT1114S Input Voltage Range Common-Mode Rejection Ratio Power Supply Rejection Ratio Large-Signal Voltage Gain Output Voltage Swing Slew Rate Supply Current per Amplifier Offset Voltage Match (Note 5) Offset Voltage Match Drift (Notes 5, 8) ∆IB+ ∆CMRR ∆PSRR Noninverting Bias Current Match (Notes 5, 6) Common-Mode Rejection Ratio Power Supply Rejection Ratio LT1112N8 LT1112S8, LT1114N/S LT1112N8 LT1112S8, LT1114N/S LT1114S (Notes 5, 7) (Notes 5, 7) VCM = ± 13.5V VS = ± 1.2V to ± 20V VO = ± 12V, RL = 10kΩ VO = ± 10V, RL = 2kΩ RL = 10kΩ q q q q q q q q q q q q q q q 440 170 220 0.7 1.6 530 4 LT1112/LT1114 ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER VOS ∆VOS ∆Temp IOS IB VCM CMRR PSRR AVOL VOUT SR IS ∆VOS Input Offset Voltage VS = ±15V, – 40°C ≤ TA ≤ 85°C, (Note 10) LT1112ACN8 LT1114ACN MIN TYP MAX q q q q q q q q q q CONDITIONS (Note 2) LT1112N8 LT1112S8, LT1114N/S VS = ± 1.2V LT1112N8 LT1112S8, LT1114N/S LT1114S LT1112N8/S8 LT1114CN/S MIN TYP MAX 35 45 60 0.20 0.40 85 110 ± 120 ± 150 ± 13.5 112 111 600 300 0.13 ± 14.1 132 125 3300 900 0.24 370 60 70 0.3 0.5 155 190 109 107 133 127 510 225 270 1.0 1.9 770 1300 135 160 240 0.75 1.30 400 600 ± 550 ± 800 UNITS µV µV µV µV/°C µV/°C pA pA pA pA V dB dB V/mV V/mV V V/µs µA µV µV µV/°C µV/°C pA pA dB dB 30 40 55 0.15 0.30 70 ± 110 ± 13.5 117 113 700 400 0.13 ± 14.1 132 125 3300 1100 0.24 370 50 60 0.2 0.4 140 113 110 133 127 110 135 200 0.50 1.10 330 ± 500 Average Input Offset Voltage Drift Input Offset Current Input Bias Current LT1114S Input Voltage Range Common-Mode Rejection Ratio Power Supply Rejection Ratio Large-Signal Voltage Gain Output Voltage Swing Slew Rate Supply Current per Amplifier Offset Voltage Match (Note 5) Offset Voltage Match Drift (Notes 5) ∆ IB + ∆CMRR ∆PSRR Noninverting Bias Current Match (Notes 5, 6) Common-Mode Rejection Ratio Power Supply Rejection Ratio LT1112N8 LT1112S8, LT1114N/S LT1112N8 LT1112S8, LT1114N/S LT1114S (Notes 5, 7) (Notes 5, 7) VCM = ± 13.5V VS = ± 1.2V to ± 20V VO = ± 12V, RL = 10kΩ VO = ± 10V, RL = 2kΩ RL = 10kΩ q q q q q q q q q q q q q q q ± 13.0 ± 13.85 450 180 230 0.7 1.6 660 ± 13.0 ± 13.85 The q denotes specifications which apply over the 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: Typical parameters are defined as the 60% yield of parameter distributions of individual amplifiers; i.e., out of 100 LT1114s (or 100 LT1112s) typically 240 op amps (or 120) will be better than the indicated specification. Note 3: This parameter is guaranteed by design and is not tested. Note 4: Offset voltage, supply current and power supply rejection ratio are measured at the minimum supply voltage. Note 5: Matching parameters are the difference between amplifiers A and D and between B and C on the LT1114; between the two amplifiers on the LT1112. Note 6: This parameter is the difference between two noninverting input bias currents. Note 7: ∆CMRR and ∆PSRR are defined as follows: (1) CMRR and PSRR are measured in µV/V on the individual amplifiers. (2) The difference is calculated between the matching sides in µV/V. (3) The result is converted to dB. Note 8: This parameter is not 100% tested. Note 9: These parameters are not tested. More than 99% of the op amps tested during product characterization have passed the maximum limits. 100% passed at 1kHz. Note 10: The LT1112/LT1114 are not tested and are not quality assurance sampled at – 40°C and at 85°C. These specifications are guaranteed by design, correlation and/or inference from – 55°C, 0°C, 25°C, 70°C and/or 125°C tests. 5 LT1112/LT1114 TYPICAL PERFOR A CE CHARACTERISTICS Input Bias and Offset Current, Noninverting Bias Current Match vs Temperature INPUT BIAS, OFFSET, MATCH CURRENT (pA) 200 ∆IB+ IOS 0 IB (UNDERCANCELLED) 100 INPUT BIAS CURRENT (pA) 50 0 –50 PERCENT OF UNITS –100 –100 –200 –75 –50 –25 0 25 50 75 TEMPERATURE (°C) VS = ± 15V VCM 100 125 –150 –15 10 –5 0 5 –10 COMMON-MODE INPUT VOLTAGE (V) LT1112/14 • TPC01 Drift with Temperature LT1112N8/J8, LT1114J 20 850 OP AMPS TESTED 100 LT1112J8 165 LT1112N8 80 LT1114J VS = ± 15V Drift with Temperature LT1112S8, LT1114N/S 25 960 OP AMPS TESTED 240 LT1112S8 80 LT1114N 40 LT1114S VS = ± 15V 30 20 PERCENT OF INPUTS PERCENT OF UNITS 15 PERCENT OF UNITS 15 10 10 5 5 0 –0.8 –0.6 –0.4 –0.2 0 0.2 0.4 0.6 0.8 OFFSET VOLTAGE DRIFT WITH TEMPERATURE (µV/°C) LT1112/14 • TPC04 0 0.6 1.0 1.4 –1.4 –1.0 –0.6 –0.2 0.2 OFFSET VOLTAGE DRIFT WITH TEMPERATURE (µV/°C) LT1112/14 • TPC05 Distribution of Offset Voltage Match 25 VS = ±15V TA = 25°C 20 PERCENT ON UNITS PERCENT OF UNITS Distribution of Offset Voltage Match Drift (LT1112J8, LT1112N8, LT1114J Packages) 30 25 20 15 10 5 0 –0.8 –0.6 –0.4 –0.2 0 0.2 0.4 0.6 0.8 OFFSET VOLTAGE MATCH DRIFT (µV/°C) LT1112/14 • TPC08 VS = ±15V 342 PAIRS TESTED 15 PERCENT OF UNITS 15 10 5 0 –100 –80 –60 – 40 –20 0 20 40 60 80 100 ∆VOS, OFFSET VOLTAGE MATCH (µV) LT1112/14 • TPC07 6 + IB – IB (OVERCANCELLED) UW Input Bias Current Over Common-Mode Range 150 100 VS = ±15V TA = 25°C RINCM = 800GΩ DEVICE WITH POSITIVE INPUT CURRENT DEVICE WITH NEGATIVE INPUT CURRENT 20 30 Distribution of Input Bias Current (In All Packages Except LT1114S) VS = ± 15V TA = 25°C 10 15 0 0 100 200 –300 –200 –100 INPUT BIAS CURRENT (pA) 300 LT1112/14 • TPC02 LT1112/14 • TPC03 Distribution of Offset Voltage at VS = ± 1.0V (In All Packages) TA = 25°C 25 20 15 10 5 0 –80 –60 –40 –20 0 20 40 60 80 100 INPUT OFFSET VOLTAGE (µV) LT1112/14 • TPC06 Distribution of Offset Voltage Match Drift (LT1112S8, LT1114N, LT1114S Packages) 20 VS = ±15V 364 PAIRS TESTED 10 5 0 –1.6 –1.2 –0.8 –0.4 0 0.4 0.8 1.2 1.6 OFFSET VOLTAGE MATCH DRIFT (µV/°C) LT1112/14 • TPC09 LT1112/LT1114 TYPICAL PERFOR A CE CHARACTERISTICS Noise Spectrum 1000 VOLTAGE NOISE DENSITY (nV/√Hz) CURRENT NOISE DENSITY (fA/√Hz) VS = ±1V TO ±20V TA = 25°C NOISE VOLTAGE (0.2µV/DIV) 100 CURRENT NOISE VOLTAGE NOISE 10 1/fCORNER 2.5Hz 1/fCORNER 140Hz 10 100 FREQUENCY (Hz) 1000 LT1112/14 • TPC10 1 1 0 2 6 4 TIME (SEC) NOISE VOLTAGE (0.2µV/DIV) Warm-Up Drift 3 CHANGE IN OFFSET VOLTAGE (µV) CHANGE IN OFFSET VOLTAGE (µV) 2A 4 2 0 –2 –4 –6 SUPPLY CURRENT PER AMPLIFIER (µA) VS = ±15V TA = 25°C 2 LT1112S8, LT1114N/S PACKAGES 1 LT1114J PACKAGE LT1112J8, N8 PACKAGES 0 0 0.5 1.0 1.5 2.0 TIME AFTER POWER ON (MINUTES) 2.5 MINIMUM SUPPLY (V) Minimum Supply Voltage vs Temp Voltage Gain at Minimum Supply Voltage COMMON-MODE RANGE OR OUTPUT SWING (V) ±1.2 ±1.1 ±1.0 ±0.9 V + – 0.8 V + – 1.0 V – + 0.8 V – + 0.6 V – + 0.4 V – + 0.2 V– –75 OUTPUT SWING (V) VOLTAGE GAIN (V/mV) 100 80 60 40 –50 –25 50 25 0 75 TEMPERATURE (°C) UW LT1112/14 • TPC13 0.1Hz to 10Hz Noise VS = ± 15V TA = 25°C 0.01Hz to 1Hz Noise VS = ±15V TA = 25°C 8 10 0 20 60 40 TIME (SEC) 80 100 LT1112/14 • TPC11 LT1112/14 • TPC12 Long Term Stability of Three Representative Units 6 VS = ±15V TA = 25°C 600 Supply Current per Amplifier vs Supply Voltage 500 3A 2B 1A 3B 1B 400 TA = 125°C TA = 25°C TA = – 55°C 300 0 1 2 3 4 TIME (MONTHS) 5 6 200 0 ±10 ±15 ±5 SUPPLY VOLTAGE (V) ±20 LT1112/14 • TPC14 LT1112/14 • TPC15 Common-Mode Range and Voltage Swing with Respect to Supply Voltages V+ V + – 0.2 V + – 0.4 V + – 0.6 SWING CM RANGE VS = ±1V TO ±20V IL < 100µA V+ V+ – 1 V+ – 2 V+ – 3 V– + 3 V– + 2 V– + 1 Output Voltage Swing vs Load Current VS = ±1V TO ± 20V TA = 25°C MAX IL AT ±1V = 1.3mA AT ±1.5V = 3mA SWING CM RANGE 100 125 –25 25 75 TEMPERATURE (°C) 125 V– –9 –6 SINK 6 SOURCE OUTPUT CURRENT (mA) –3 0 3 9 LT1112/14 • TPC16 LT1112/14 • TPC17 LT1112/14 • TPC18 7 LT1112/LT1114 TYPICAL PERFOR A CE CHARACTERISTICS Voltage Gain –15 VS = ±15V TA = 25°C VOLTAGE GAIN (dB) CHANGE IN OFFSET VOLTAGE (µV) –10 –5 RL = 10k 0 RL = 2k 5 10 GAIN (dB) 15 –15 –10 –5 0 5 OUTPUT VOLTAGE (V) Common-Mode Rejection vs Frequency 140 140 COMMON-MODE REJECTION RATIO (dB) 120 100 80 60 40 20 0 1 10 10k 1k 100 FREQUENCY (Hz) POWER SUPPLY REJECTION RATIO (dB) VS = ±15V TA = 25°C NEGATIVE SUPPLY CHANNEL SEPARATION (dB) Slew Rate, Gain-Bandwidth Product and Phase Margin vs Temperature GAIN-BANDWIDTH PRODUCT (kHz) SLEW RATE (V/µs) 0.4 SLEW 80 0.2 OUTPUT IMPEDANCE (Ω) 0.3 φm AV = 100 1 0.1 0.01 AV = + 1 70 OVERSHOOT (%) 800 GBW 700 60 600 –50 –25 50 25 0 75 TEMPERATURE (°C) 8 UW 10 15 LT1112/14 • TPC19 Voltage Gain vs Frequency 140 120 100 VS = ±15V TA = 25°C 30 40 Gain, Phase Shift vs Frequency 100 VS = ±15V TA = 25°C 120 PHASE SHIFT (DEG) PHASE 80 60 40 20 0 –20 0.01 0.1 1 10 100 1k 10k 100k 1M 10M FREQUENCY (Hz) LT1112/14 • TPC20 20 GAIN 10 140 160 0 PHASE MARGIN = 70°C 180 –10 0.01 200 0.1 1 10 LT1112/14 • TPC21 FREQUENCY (MHz) Power Supply Rejection vs Frequency 160 VS = ±15V TA = 25°C Channel Separation vs Frequency VS = ±15V TA = 25°C 140 120 100 80 POSITIVE SUPPLY 60 40 120 100 AMP 1 IN UNITY-GAIN 20VP-P, RL = 2k AMP 2 IN GAIN = 1000 RS = 100Ω, RF = 100k 1 10 1k 100 10k FREQUENCY (Hz) 100k 1M 80 20 0.1 1 10 100 1k 10k FREQUENCY (Hz) 100k 1M 100k 1M LT1112/14 • TPC22 LT1112/14 • TPC23 LT1112/14 • TPC24 Closed-Loop Output Impedance 1000 100 PHASE MARGIN (DEG) 120 Capacitive Loading Handling VS = ±15V TA = 25°C VS = ±15V TA = 25°C 100 80 60 10 AV = + 1 40 AV = 10 20 0 0.1 0.00001 0.0001 0.001 0.01 CAPACITIVE LOAD (µF) 100 125 0.001 1 10 100 1k 10k FREQUENCY (Hz) 100k 1M 1 10 LT1112/14 • TPC25 LT1112/14 • TPC26 LT1112/14 • TPC27 LT1112/LT1114 TYPICAL PERFOR A CE CHARACTERISTICS Small-Signal Transient Response Large-Signal Transient Response 28 PEAK-TO-PEAK OUTPUT VOLTAGE (V) 20mV/DIV 5V/DIV 2µs/DIV AV = +1 CL = 500pF VS = ±15V AV = +1 RF = 10k CF = 100pF VS = ±15V APPLICATI S I FOR ATIO The LT1112 dual and LT1114 quad in the plastic and ceramic DIP packages are pin compatible to and directly replace such precision op amps as the OP-200, OP-297, AD706 duals and OP-400, OP-497, AD704 quads with improved price/performance. The LT1112 in the S8 surface mount package has the standard pin configuration, i.e., the same configuration as the plastic and ceramic DIP packages. The LT1114 quad is offered in the narrow 16-pin surface mount package. All competitors are in the wide 16-pin package which occupies 1.8 times the area of the narrow package. The wide package is also 1.8 times thicker than the narrow package. The inputs of the LT1112/1114 are protected with back-toback diodes. In the voltage follower configuration, when Voltage Follower with Input Exceeding the Common-Mode Range (VS = ± 5V) INPUT: ± 5.2V Sine Wave U W UW Undistorted Output Voltage vs Frequency TA = 25°C RL = 10k VS = ±15V 20 16 12 8 4 0 1 10 100 FREQUENCY (kHz) 1000 LT1112/14 • TPC30 24 VS = ± 5V 50µs/DIV U UO the input is driven by a fast large-signal pulse (>1V), the input 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 is recommended because this resistor keeps the current below the short-circuit limit, resulting in faster recovery and settling of the output. The input voltage of the LT1112/1114 should never exceed the supply voltages by more than a diode drop. However, the example below shows that as the input voltage exceeds the common-mode range, the LT1112’s output clips cleanly, without any glitches or phase reversal. The OP297 exhibits phase reversal. The photos also illustrate that both the input and output ranges of the LT1112 are within LT1112 Output OP-297 Output 9 LT1112/LT1114 APPLICATI S I FOR ATIO U Input offset current = 100pA Input resistance = 800GΩ Input noise = 0.42µVP-P Three Op Amp Instrumentation Amplifier IN– 1/2 LT1112 OR 1/4 LT1114 –A 800mV of the supplies. The effect of input and output overdrive on the other amplifiers in the LT1112 or LT1114 packages is negligible, as each amplifier is biased independently. Advantages of Matched Dual and Quad 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 LT1112. 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 noninverting input currents (IB+). The difference between these two currents (∆IB+) is the offset current of the instrumentation amplifier. Common-mode 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 = + 1µV/V or 120dB, and CMRRB = + 0.75µV/V or 122.5dB, then ∆CMRR = 0.25µV/V or 132dB; if CMRRB = – 0.75µV/V which is still 122.5dB, then ∆CMRR = 1.75µV/V or 115dB. Clearly the LT1112/LT1114, by specifying and guaranteeing all of these matching parameters, can significantly improve the performance of matching-dependent circuits. Typical performance of the instrumentation amplifier: Input offset voltage = 35µV Offset voltage drift = 0.3µV/°C Input bias current = 80pA R8 200Ω R2 R5 10k 100Ω 1% 0.5% IN+ 1/2 LT1112 OR 1/4 LT1114 D R7 9.88k 0.5% R9 200Ω When the instrumentation amplifier is used with high impedance sources, the LT1114 is recommended because its CMRR vs frequency performance is better than the LT1112’s. For example, with two matched 1MΩ source resistors, CMRR at 100Hz is 100dB with the LT1114, 76dB with the LT1112. This difference is explained by the fact that capacitance between adjacent pins on an IC package is about 0.25pF (including package, socket and PC board trace capacitances). On the dual op amp package, positive input A is next to the V – pin (AC ground), while positive input B has no AC ground pin adjacent to it, resulting in a 0.25pF input capacitance mismatch. At 100Hz, 0.25pF represents a 6.4 × 109 input impedance mismatch, which is only 76dB higher than the 1MΩ source resistors. On the quad package, all four inputs are adjacent to a power supply terminal–therefore, there is no mismatch. 10 + C1 33pF R10 1M LT1097 OR 1/4LT1114 B OR C – + – W U UO + R4 100Ω 0.5% R1 10k 1% R3 2.1k 1% R6 10k 0.5% OUTPUT GAIN = 1000 TRIM R8 FOR GAIN TRIM R9 FOR DC COMMON-MODE REJECTION TRIM R10 FOR AC COMMON-MODE REJECTION LT1112/14 • AI02 LT1112/LT1114 TYPICAL APPLICATI Dual Buffered ± 0.617V Reference Powered by Two AA Batteries +1.5V 15k RX* LT1004-1.2 100pF 1/2 LT1112 RY* *OPTIONAL –1.5V SCHE ATIC DIAGRA 12pF 30k Q35 Q34 30k (1/2 LT1112, 1/4 LT1114) V+ 20µA 35µA Q19 1.5k Q21 Q33 Q25 S Q27 Q29 Q24 28Ω 3k Q11 Q23 2.5k Q20 Q26 Q28 Q32 90Ω 30Ω OUT 80µA Q22 800Ω 30pF 4k Q5 Q6 Q8 Q7 Q13 Q4 INVERTING INPUT S Q1 Q2 S S Q3 50k 1.5k Q12 J1 Q16 10k Q18 460Ω 15µA 5µA 5µA V– 460Ω 460Ω Q14 Q15 200Ω Q17 Q30 – Q9 NONINVERTING INPUT Q10 + 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 circuits as described herein will not infringe on existing patent rights. – + W UO + 1/2 LT1112 *OPTIONAL +0.617V – 20k 0.1% TOTAL SUPPLY CURRENT = 700µA WORKS WITH BATTERIES DISCHARGED TO ±1.3V AT ±1.5V: MAXIMUM LOAD CURRENT = 800µA; CAN BE INCREASED WITH OPTIONAL RX, RY; AT RX = RY = 750Ω LOAD CURRENT = 2mA TEMPERATURE COEFFICIENT LIMITED BY REFERENCE = 20ppm/°C 20k 0.1% –0.617V LT1112/14 • TA03 W Q31 200Ω Q1 TO Q4 ARE SUPERGAIN TRANSISTORS LT1112/14 • SD01 11 LT1112/LT1114 PACKAGE DESCRIPTIO 0.290 – 0.320 (7.366 – 8.128) J8 Package 8-Lead Ceramic DIP 0.008 – 0.018 (0.203 – 0.460) 0.385 ± 0.025 (9.779 ± 0.635) 0° – 15° 0.300 – 0.320 (7.620 – 8.128) N8 Package 8-Lead Plastic DIP 0.009 – 0.015 (0.229 – 0.381) +0.025 0.325 –0.015 8.255 +0.635 –0.381 ( ) 0.010 – 0.020 × 45° (0.254 – 0.508) S8 Package 8-Lead Plastic SOIC 0°– 8° TYP 0.016 – 0.050 0.406 – 1.270 0.008 – 0.010 (0.203 – 0.254) 0.290 – 0.320 (7.366 – 8.128) J Package 14-Lead Ceramic DIP 0.008 – 0.018 (0.203 – 0.460) 0.385 ± 0.025 (9.779 ± 0.635) 0° – 15° 0.300 – 0.325 (7.620 – 8.255) N Package 14-Lead Plastic DIP 0.009 – 0.015 (0.229 – 0.381) +0.025 0.325 –0.015 8.255 +0.635 –0.381 ( ) S Package 16-Lead Plastic SOIC 0° – 8° TYP 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0.016 – 0.050 0.406 – 1.270 12 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7487 (408) 432-1900 q FAX: (408) 434-0507 q TELEX: 499-3977 U Dimensions in inches (millimeters) unless otherwise noted. 0.200 (5.080) MAX 0.015 – 0.060 (0.381 – 1.524) 0.005 (0.127) MIN 0.405 (10.287) MAX 8 7 6 5 0.025 (0.635) RAD TYP 1 2 3 0.220 – 0.310 (5.588 – 7.874) 4 0.038 – 0.068 (0.965 – 1.727) 0.014 – 0.026 (0.360 – 0.660) 0.125 3.175 0.100 ± 0.010 MIN (2.540 ± 0.254) 0.055 (1.397) MAX 0.045 – 0.065 (1.143 – 1.651) 0.130 ± 0.005 (3.302 ± 0.127) 0.400 (10.160) MAX 8 7 6 5 0.065 (1.651) TYP 0.125 (3.175) MIN 0.020 (0.508) MIN 0.250 ± 0.010 (6.350 ± 0.254) 0.045 ± 0.015 (1.143 ± 0.381) 0.100 ± 0.010 (2.540 ± 0.254) 1 2 3 4 0.018 ± 0.003 (0.457 ± 0.076) 0.189 – 0.197 (4.801 – 5.004) 0.053 – 0.069 (1.346 – 1.752) 0.004 – 0.010 (0.101 – 0.254) 0.228 – 0.244 (5.791 – 6.197) 8 7 6 5 0.014 – 0.019 (0.355 – 0.483) 0.050 (1.270) BSC 0.150 – 0.157 (3.810 – 3.988) 1 2 3 4 0.200 (5.080) MAX 0.015 – 0.060 (0.381 – 1.524) 0.005 (0.127) MIN 0.785 (19.939) MAX 14 13 12 11 10 9 8 0.025 (0.635) RAD TYP 0.220 – 0.310 (5.588 – 7.874) 1 0.038 – 0.068 (0.965 – 1.727) 0.014 – 0.026 (0.360 – 0.660) 0.100 ± 0.010 (2.540 ± 0.254) 0.125 (3.175) MIN 0.098 (2.489) MAX 2 3 4 5 6 7 0.015 (0.380) MIN 0.130 ± 0.005 (3.302 ± 0.127) 0.045 – 0.065 (1.143 – 1.651) 0.065 (1.651) TYP 14 13 12 0.770 (19.558) MAX 11 10 9 8 0.260 ± 0.010 (6.604 ± 0.254) 0.075 ± 0.015 (1.905 ± 0.381) 0.018 ± 0.003 (0.457 ± 0.076) 0.100 ± 0.010 (2.540 ± 0.254) 0.125 (3.175) MIN 1 2 3 4 5 6 7 0.386 – 0.394 (9.804 – 10.008) 0.053 – 0.069 (1.346 – 1.752) 0.004 – 0.010 (0.101 – 0.254) 16 15 14 13 12 11 10 9 0.014 – 0.019 (0.355 – 0.483) 0.050 (1.270) TYP 0.228 – 0.244 (5.791 – 6.197) 0.150 – 0.157 (3.810 – 3.988) 1 2 3 4 5 6 7 8 LT/GP 1292 10K REV 0 © LINEAR TECHNOLOGY CORPORATION 1992