LT1125

LT1124/LT1125 Dual/Quad Low Noise, High Speed Precision Op Amps DESCRIPTIO The LT®1124 dual and LT1125 quad are high performance op amps that offer higher gain, slew rate and bandwidth than the industry standard OP-27 and competing OP-270/ OP-470 op amps. In addition, the LT1124/LT1125 have lower IB and IOS than the OP-27; lower VOS and noise than the OP-270/OP-470. 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. Slew rate, gain bandwidth and 1kHz noise are 100% tested for each individual amplifier. Consequently, the specifications of even the lowest cost grades (the LT1124C and the LT1125C) have been spectacularly improved compared to equivalent grades of competing amplifiers. Power consumption of the LT1124 is one half of two OP-27s. Low power and high performance in an 8-pin SO package make the LT1124 a first choice for surface mounted systems and where board space is restricted. For a decompensated version of these devices, with three times higher slew rate and bandwidth, please see the LT1126/LT1127 data sheet. FEATURES s s s s s s s s s 100% Tested Low Voltage Noise: 2.7nV/√Hz Typ 4.2nV/√Hz Max Slew Rate: 4.5V/µs Typ Gain Bandwidth Product: 12.5MHz Typ Offset Voltage, Prime Grade: 70µV Max Low Grade: 100µV Max High Voltage Gain: 5 Million Min Supply Current Per Amplifier: 2.75mA Max Common Mode Rejection: 112dB Min Power Supply Rejection: 116dB Min Available in 8-Pin SO Package APPLICATIO S s s s s s s s s Two and Three Op Amp Instrumentation Amplifiers Low Noise Signal Processing Active Filters Microvolt Accuracy Threshold Detection Strain Gauge Amplifiers Direct Coupled Audio Gain Stages Tape Head Preamplifiers Infrared Detectors , LTC and LT are registered trademarks of Linear Technology Corporation. Protected by U.S. patents 4,775,884 and 4,837,496. TYPICAL APPLICATIO 3 Instrumentation Amplifier with Shield Driver + 1/4 LT1125 1 1k RF 3.4k 5 30k Input Offset Voltage Distribution (All Packages, LT1124 and LT1125) VS = ± 15V TA = 25°C 758 DUALS 200 QUADS 2316 UNITS TESTED 2 – 15V 30 GUARD INPUT + – GUARD + 8 1/4 LT1125 10 OUTPUT 30k 6 RG 100Ω – PERCENT OF UNITS RG 100Ω + 4 1/4 LT1125 11 –15V 7 20 – 9 10 13 – 1/4 LT1125 14 RF 3.4k 1k GAIN = 30 (1 + RF/RG) ≈ 1000 POWER BW = 170kHz SMALL-SIGNAL BW = 400kHz NOISE = 3.8µV/√Hz AT OUTPUT VOS = 35µV 0 –100 12 + 1124/25 TA01 U U U 20 60 – 60 – 20 INPUT OFFSET VOLTAGE (µV) 100 1124/25 TA02 1 LT1124/LT1125 ABSOLUTE AXI U RATI GS (Note 1) Operating Temperature Range LT1124AC/LT1124C LT1125AC/LT1125C (Note 10) .......... – 40°C to 85°C LT1124AI/LT1124I ............................ – 40°C to 85°C LT1124AM/LT1124M LT1125AM/LT1125M ...................... – 55°C to 125°C Supply Voltage ..................................................... ± 22V Input Voltages ......................... Equal to Supply Voltage Output Short-Circuit Duration ......................... Indefinite Differential Input Current (Note 6) ..................... ± 25mA Lead Temperature (Soldering, 10 sec)................. 300°C Storage Temperature Range ................ – 65°C to 150°C PACKAGE/ORDER I FOR ATIO TOP VIEW +IN A 1 V– 2 +IN B 3 B –IN B 4 5 OUT B A 8 7 6 –IN A OUT A V+ ORDER PART NUMBER LT1124CS8 LT1124AIS8 LT1124IS8 S8 PART MARKING 1124 1124AI 1124I LT1125CS OUT A –IN A +IN A V+ +IN B –IN B OUT B 1 2 3 4 5 6 7 OUT A 1 –IN A 2 +IN A 3 V – S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 140°C, θJA = 190°C NOTE: THIS PIN CONFIGURATION DIFFERS FROM THE 8-PIN PDIP CONFIGURATION. INSTEAD, IT FOLLOWS THE INDUSTRY STANDARD LT1013DS8 SO PACKAGE PIN LOCATIONS TOP VIEW OUT A 1 A D 16 OUT D 15 –IN D 14 +IN D 13 V – B C 12 +IN C 11 –IN C 10 OUT C 9 NC –IN A 2 +IN A 3 V+ 4 +IN B 5 –IN B 6 OUT B 7 NC 8 SW PACKAGE 16-LEAD PLASTIC (WIDE) SO TJMAX = 140°C, θJA = 130°C ELECTRICAL CHARACTERISTICS SYMBOL VOS ∆VOS ∆Time IOS PARAMETER Input Offset Voltage Long Term Input Offset Voltage Stability Input Offset Current LT1124 LT1125 LT1124 LT1125 TA = 25°C, VS = ± 15V, unless otherwise noted. LT1124AC/AI/AM LT1125AC/AM MIN TYP MAX 20 25 0.3 5 6 15 20 70 90 LT1124/C/I/M LT1125/C/M MIN TYP MAX 25 30 0.3 6 7 20 30 100 140 CONDITIONS (Note 2) 2 U U W WW U W TOP VIEW 8 A B 4 5 7 6 V+ OUT B –IN B +IN B ORDER PART NUMBER LT1124CJ8 LT1124ACN8 LT1124CN8 LT1124AMJ8 LT1124MJ8 J8 PACKAGE 8-LEAD CERDIP N8 PACKAGE 8-LEAD PDIP TJMAX = 160°C, θJA = 100°C (J8) TJMAX = 140°C, θJA = 130°C (N8) TOP VIEW 14 OUT D A D 13 –IN D 12 +IN D 11 V – B C 10 +IN C 9 8 –IN C OUT C LT1125CJ LT1125ACN LT1125CN LT1125AMJ LT1125MJ J PACKAGE N PACKAGE 14-LEAD CERDIP 14-LEAD PDIP TJMAX = 160°C, θJA = 80°C (J) TJMAX = 140°C, θJA = 110°C (N) UNITS µV µV µV/Mo nA nA LT1124/LT1125 ELECTRICAL CHARACTERISTICS SYMBOL IB en PARAMETER Input Bias Current Input Noise Voltage Input Noise Voltage Density in VCM CMRR PSRR AVOL VOUT SR GBW ZO IS Input Noise Current Density Input Voltage Range Common Mode Rejection Ratio Power Supply Rejection Ratio Large-Signal Voltage Gain Maximum Output Voltage Swing Slew Rate Gain Bandwidth Product Open-Loop Output Resistance Supply Current per Amplifier Channel Separation f ≤ 10Hz (Note 9) VOUT = ±10V, RL = 2k 134 VCM = ±12V VS = ± 4V to ±18V RL ≥ 10k, VOUT = ±10V RL ≥ 2k, VOUT = ±10V RL ≥ 2k RL ≥ 2k (Notes 3, 7) fO = 100kHz (Note 3) VOUT = 0, IOUT = 0 0.1Hz to 10Hz (Notes 8, 9) fO = 10Hz (Note 4) fO = 1000Hz (Note 3) fO = 10Hz fO = 1000Hz ±12 112 116 5 2 ±13 3 9 TA = 25°C, VS = ±15V, unless otherwise noted. LT1124AC/AI/AM LT1125AC/AM MIN TYP MAX ±7 70 3.0 2.7 1.3 0.3 ±12.8 126 126 17 4 ±13.8 4.5 12.5 75 2.3 150 2.75 130 ±12 106 110 3.0 1.5 ±12.5 2.7 8 ± 20 200 5.5 4.2 LT1124C/I/M LT1125C/M MIN TYP MAX ±8 70 3.0 2.7 1.3 0.3 ±12.8 124 124 15 3 ±13.8 4.5 12.5 75 2.3 150 2.75 5.5 4.2 ± 30 CONDITIONS (Note 2) UNITS nA nVP-P nV/√Hz nV/√Hz pA/√Hz pA/√Hz V dB dB V/µV V/µV V V/µs MHz Ω mA dB The q denotes the specifications which apply over the –55°C ≤ TA ≤ 125°C temperature range, VS = ± 15V, unless otherwise noted. LT1124AM LT1125AM MIN TYP MAX q q q q q q q SYMBOL VOS ∆VOS ∆Temp IOS IB VCM CMRR PSRR AVOL VOUT SR IS PARAMETER 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 Maximum Output Voltage Swing Slew Rate Supply Current per Amplifier CONDITIONS (Note 2) LT1124 LT1125 (Note 5) LT1124 LT1125 LT1124M LT1125M MIN TYP MAX 60 70 0.4 20 20 ± 20 ±11.3 100 104 2.0 0.7 ±12 2 ±12 120 120 10 2 ±13.6 3.8 2.5 3.25 250 290 1.5 60 70 ± 70 UNITS µV µV µV/°C nA nA nA V dB dB V/µV V/µV V V/µs mA 50 55 0.3 18 18 ± 18 ±11.3 106 110 3 1 ±12.5 2.3 ±12 122 122 10 3 ±13.6 3.8 2.5 170 190 1.0 45 55 ± 55 VCM = ±11.3V VS = ±4V to ±18V RL ≥ 10k, VOUT = ±10V RL ≥ 2k, VOUT = ±10V RL ≥ 2k RL ≥ 2k (Notes 3, 7) q q q q q q q 3.25 3 LT1124/LT1125 temperature range, VS = ±15V, unless otherwise noted. SYMBOL VOS ∆VOS ∆Temp IOS IB VCM CMRR PSRR AVOL VOUT SR IS PARAMETER 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 Maximum Output Voltage Swing Slew Rate Supply Current per Amplifier ELECTRICAL CHARACTERISTICS The q denotes the specifications which apply over the 0°C ≤ TA ≤ 70°C LT1124AC LT1125AC MIN TYP MAX 35 120 40 140 0.3 1 6 7 ±8 ±12.4 125 125 15 3.5 ±13.7 4 2.4 25 35 ± 35 ±11.5 102 107 2.5 1.0 ±12 2.4 3 LT1124C LT1125C MIN TYP MAX 45 170 50 210 0.4 1.5 7 8 ±9 ±12.4 122 122 14 2.5 ±13.7 4 2.4 35 45 ± 45 CONDITIONS (Note 2) LT1124 LT1125 (Note 5) LT1124 LT1125 q q q q q q q UNITS µV µV µV/°C nA nA nA V dB dB V/µV V/µV V V/µs mA VCM = ±11.5V VS = ±4V to ±18V RL ≥ 10k, VOUT = ±10V RL ≥ 2k, VOUT = ±10V RL ≥ 2k RL ≥ 2k (Notes 3, 7) q q q q q q q ±11.5 109 112 4.0 1.5 ±12.5 2.6 3 The q denotes the specifications which apply over the –40°C ≤ TA ≤ 85°C temperature range, VS = ±15V, unless otherwise noted. (Note 10) LT1124AC/AI LT1125AC MIN TYP MAX 40 140 45 160 0.3 1 15 15 ± 15 ±12.2 124 124 12 3.2 ±13.6 3.9 2.4 40 50 ± 50 ±11.4 101 106 2.2 0.8 ±12 2.1 3.25 LT1124C/I LT1125C MIN TYP 50 55 0.4 17 17 ± 17 ±12.2 121 121 12 2.3 ±13.6 3.9 2.4 SYMBOL VOS ∆VOS ∆Temp IOS IB VCM CMRR PSRR AVOL VOUT SR IS PARAMETER 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 Maximum Output Voltage Swing Slew Rate Supply Current per Amplifier CONDITIONS (Note 2) LT1124 LT1125 (Note 5) LT1124 LT1125 q q q q q q q MAX 200 240 1.5 55 65 ± 65 UNITS µV µV µV/°C nA nA nA V dB dB V/µV V/µV V V/µs mA VCM = ±11.4V VS = ±4V to ±18V RL ≥ 10k, VOUT = ±10V RL ≥ 2k, VOUT = ±10V RL ≥ 2k RL ≥ 2k (Notes 3, 7) q q q q q q q ±11.4 107 111 3.5 1.2 ±12.5 2.4 3.25 Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: Typical parameters are defined as the 60% yield of parameter distributions of individual amplifiers; i.e., out of 100 LT1125s (or 100 LT1124s) typically 240 op amps (or 120) will be better than the indicated specification. Note 3: This parameter is 100% tested for each individual amplifier. Note 4: This parameter is sample tested only. Note 5: This parameter is not 100% tested. Note 6: The inputs are protected by back-to-back diodes. Current limiting resistors are not used in order to achieve low noise. If differential input voltage exceeds ±1.4V, the input current should be limited to 25mA. Note 7: Slew rate is measured in AV = –1; input signal is ±7.5V, output measured at ± 2.5V. Note 8: 0.1Hz to 10Hz noise can be inferred from the 10Hz noise voltage density test. See the test circuit and frequency response curve for 0.1Hz to 10Hz tester in the Applications Information section of the LT1007 or LT1028 data sheets. Note 9: This parameter is guaranteed but not tested. Note 10: The LT1124C/LT1125C and LT1124AC/LT1125AC are guaranteed to meet specified performance from 0°C to 70°C and are designed, characterized and expected to meet these extended temperature limits, but are not tested at –40°C and 85°C. The LT1124AI and LT1124I are guaranteed to meet the extended temperature limits. 4 LT1124/LT1125 TYPICAL PERFOR A CE CHARACTERISTICS 0.1Hz to 10Hz Voltage Noise 0.01Hz to 1Hz Voltage Noise 100 RMS VOLTAGE NOISE DENSITY (nV/√Hz) VOLTAGE NOISE (40nV/DIV) VOLTAGE NOISE (40nV/DIV) 0 2 4 6 TIME (SECONDS) Current Noise vs Frequency 10.0 RMS CURRENT NOISE DENSITY (pA/√Hz) INPUT BIAS OR OFFSET CURRENT (nA) SOURCING VS = ± 15V TA = 25°C SHORT-CIRCUIT CURRENT (mA) 3.0 1.0 MAXIMUM 0.3 1/f CORNER 100Hz 0.1 10 100 1k FREQUENCY (Hz) 10k 1124 G04 SINKING TYPICAL Input Bias Current Over the Common Mode Range COMMON MODE REJECTION RATIO (dB) VS = ± 15V 15 TA = 25°C 20 160 140 120 100 80 60 40 20 0 POWER SUPPLY REJECTION RATIO (dB) INPUT BIAS CURRENT (nA) 10 5 0 –5 – 10 –15 –20 –15 –10 –5 5 10 0 COMMON MODE INPUT VOLTAGE (V) 15 DEVICE WITH NEGATIVE INPUT CURRENT DEVICE WITH POSITIVE INPUT CURRENT UW 8 10 1124/25 G01 1124/25 G07 Voltage Noise vs Frequency VS = ± 15V TA = 25°C 30 10 MAXIMUM 3 1/f CORNER 2.3Hz 1 0.1 1.0 TYPICAL 0 20 40 60 TIME (SECONDS) 80 100 10 100 FREQUENCY (Hz) 1000 1124/25 G03 1124/25 G02 Input Bias or Offset Current vs Temperature 30 VS = ± 15V 50 40 30 20 10 0 –10 –20 –30 –40 –50 Output Short-Circuit Current vs Time VS = ± 15V 25°C – 55°C 125°C 20 10 125°C 25°C –55°C 1 0 2 3 4 TIME FROM OUTPUT SHORT TO GND (MINUTES) LT1124 G06 LT1124M/LT1125M LT1124AM/LT1125AM 0 –75 –50 –25 0 25 50 75 TEMPERATURE (°C) 100 125 1124/25 G05 Common Mode Rejection Ratio vs Frequency TA = 25°C VS = ±15V VCM = ±10V 160 140 120 100 80 Power Supply Rejection Ratio vs Frequency TA = 25°C – PSRR 60 +PSRR 40 20 0 102 103 104 105 106 FREQUENCY (Hz) 107 108 1124/25 G09 1k 10k 100k 1M FREQUENCY (Hz) 10M 1124/25 G08 1 10 5 LT1124/LT1125 TYPICAL PERFOR A CE CHARACTERISTICS Voltage Gain vs Frequency 180 VS = ± 15V TA = 25°C VOLTAGE GAIN (V/ µV) 140 VOLTAGE GAIN (dB) VOLTAEG GAIN (dB) 100 60 20 – 20 0.01 1 100 10k FREQUENCY (Hz) Input Offset Voltage Drift Distribution 40 VS = ± 15V 50 200 N8 100 S8 96 J8 396 UNITS TESTED 40 30 SUPPLY CURRENT PER AMPLIFIER (mA) OFFSET VOLTAGE (µV) 30 PERCENT OF UNITS 20 10 0 –0.4 0 –0.8 0.4 0.8 INPUT OFFSET VOLTAGE DRIFT (µV/°C) 1124/25 G13 Small-Signal Transient Response OUTPUT VOLTAGE SWING (V) 50mV 0 – 50mV AVCL = + 1 VS = ±15V or ± 5V CL = 15pF 6 UW 1M 1124/25 G10 1124/25 G16 Voltage Gain vs Temperature 20 18 16 14 12 10 8 6 4 2 100M LT1124M/LT1125M –10 100 125 1124/25 G11 Gain, Phase Shift vs Frequency 50 VS = ± 15V TA = 25°C CL = 10pF 80 100 LT1124AM/LT1125AM 40 RL = 10k LT1124M/LT1125M VS = ±15V VOUT = ± 10V RL = 2k 30 20 10 0 GAIN Ø PHASE SHIFT (DEGREES) 120 140 160 180 200 100 1124/25 G12 LT1124AM/LT1125AM 0 –75 –50 –25 0 25 50 75 TEMPERATURE (°C) 0.1 1 10 FREQUENCY (MHz) Offset Voltage Drift with Temperature of Representative Units VS = ± 15V 3 Supply Current vs Supply Voltage 125°C 2 25°C –55°C 20 10 0 –10 –20 –30 –40 –50 –50 –25 75 0 25 50 TEMPERATURE (°C) 100 125 1 0 0 ±5 ± 10 ± 15 SUPPLY VOLTAGE (V) ± 20 1124/25 G15 1124/25 G14 Large-Signal Transient Response V + –0.8 –1.0 10V –1.2 –1.4 –1.6 Output Voltage Swing vs Load Current VS = ± 3V TO ± 18V 125°C 25°C –55°C 0 – 10V 1.2 1.0 0.8 0.6 125°C –55°C 25°C AVCL = – 1 VS = ±15V 1124/25 G17 V – 0.4 –10 –8 –6 –4 –2 0 2 4 6 8 10 ISINK ISOURCE OUTPUT CURRENT (mA) 1124/25 G18 LT1124/LT1125 TYPICAL PERFOR A CE CHARACTERISTICS V + –0.5 –1.0 Common Mode Limit vs Temperature 180 160 CHANNEL SEPARATION (dB) V + = 3V TO 18V –1.5 –2.0 –2.5 CHANGE IN OFFSET VOLTAGE (µV) COMMON MODE LIMIT (V) REFERRED TO POWER SUPPLY 2.5 2.0 1.5 1.0 V – = – 3V TO –18V V – 0.5 –60 –20 20 60 100 TEMPERATURE (°C) Total Harmonic Distortion and Noise vs Frequency for Noninverting Gain TOTAL HARMONIC DISTORTION + NOISE (%) TOTAL HARMONIC DISTORTION + NOISE (%) TOTAL HARMONIC DISTORTION + NOISE (%) 0.1 0.010 ZL = 2k/15pF VO = 20VP-P AV = +1, +10, +100 MEASUREMENT BANDWIDTH = 10Hz TO 80kHz AV = +100 AV = +10 0.001 AV = +1 0.0001 20 100 1k FREQUENCY (Hz) Total Harmonic Distortion and Noise vs Output Amplitude for Noninverting Gain TOTAL HARMONIC DISTORTION + NOISE (%) ZL = 2k/15pF fO = 1kHz AV = +1, +10, +100 0.1 MEASUREMENT BANDWIDTH = 10Hz TO 22kHz AV = +100 0.010 AV = +10 0.001 TOTAL HARMONIC DISTORTION + NOISE (%) 1 INTERMODULATION DISTORTION (IMD)(%) AV = +1 0.0001 0.3 1 10 OUTPUT SWING (VP-P) *See LT1115 data sheet for definition of CCIF testing UW 1124/25 G22 1124/25 G25 Channel Separation vs Frequency 10 LIMITED BY THERMAL INTERACTION Warm-Up Drift VS = ± 15V TA = 25°C SO PACKAGE 6 140 120 100 80 60 40 20 0 VS = ± 15V RL = 2k VOUT = 7VP-P TA = 25°C LIMITED BY PIN TO PIN CAPACITANCE 8 4 N, J PACKAGES 2 0 0 100 1k 10k 100k FREQUENCY (Hz) 1M 10M 0 4 1 2 3 TIME AFTER POWER ON (MINUTES) 5 140 1124/25 G19 1124/25 G20 1124/25 G21 Total Harmonic Distortion and Noise vs Frequency for Inverting Gain 0.1 0.1 ZL = 2k/15pF VO = 20Vp-p AV = –1, –10, –100 MEASUREMENT BANDWIDTH = 10Hz TO 80kHz Total Harmonic Distortion and Noise vs Frequency for Competitive Devices ZL = 2k/15pF VO = 20Vp-p AV = –10 MEASUREMENT BANDWIDTH = 10Hz TO 80kHz 0.010 0.010 AV = –100 0.001 AV = –10 AV = –1 OP270 OP27 0.001 LT1124 10k 20k 0.0001 20 100 1k FREQUENCY (Hz) 10k 20k 1124/25 G23 0.0001 20 100 1k FREQUENCY (Hz) 10k 20k 1124/25 G24 Total Harmonic Distortion and Noise vs Output Amplitude for Inverting Gain ZL = 2k/15pF fO = 1kHz AV = –1, –10, –100 0.1 MEASUREMENT BANDWIDTH = 10Hz TO 22kHz 1 0.010 Intermodulation Distortion (CCIF Method)* vs Frequency LT1124 and OP270 ZL = 2k/15pF f (IM) = 1kHz fO = 13.5kHz VO = 20Vp-p AV = –10 MEASUREMENT BANDWIDTH = 10Hz TO 80kHz 0.010 AV = –100 AV = –10 0.001 OP270 0.001 AV = –1 LT1124 30 0.0001 0.3 1 10 OUTPUT SWING (Vp-p) 30 1124/25 G26 0.0001 3k 10k FREQUENCY (Hz) 20k 1124/25 G27 7 LT1124/LT1125 APPLICATI S I FOR ATIO The LT1124 may be inserted directly into OP-270 sockets. The LT1125 plugs into OP-470 sockets. Of course, all standard dual and quad bipolar op amps can also be replaced by these devices. Matching Specifications In many applications the performance of a system depends on the matching between two op amps, rather than the individual characteristics of the two devices. The three op amp instrumentation amplifier configuration shown in this data sheet is an example. Matching characteristics are not 100% tested on the LT1124/LT1125. Some specifications are guaranteed by definition. For example, 70µV maximum offset voltage implies that mismatch cannot be more than 140µV. 112dB (= 2.5µV/V) CMRR means that worst case CMRR match is 106dB 50k* 15V 100Ω* 50k* VOUT = 1000VOS *RESISTORS MUST HAVE LOW THERMOELECTRIC POTENTIAL Figure 1. Test Circuit for Offset Voltage and Offset Voltage Drift with Temperature Table 1. Expected Match LT1124AC/AM LT1125AC/AM PARAMETER VOS Match, ∆VOS LT1124 LT1125 Temperature Coefficient Match Average Noninverting IB Match of Noninverting IB CMRR Match PSRR Match 50% YIELD 20 30 0.35 6 7 126 127 98% YIELD 110 150 1.0 18 22 115 118 50% YIELD 30 50 0.5 7 8 123 127 LT1124C/M LT1125C/M 98% YIELD 130 180 1.5 25 30 112 114 UNITS µV µV µV/°C nA nA dB dB 8 U (5µV/V). However, Table 1 can be used to estimate the expected matching performance between the two sides of the LT1124, and between amplifiers A and D, and between amplifiers B and C of the LT1125. Offset Voltage and Drift Thermocouple effects, caused by temperature gradients across dissimilar metals at the contacts to the input terminals, can exceed the inherent drift of the amplifier unless proper care is exercised. Air currents should be minimized, package leads should be short, the two input leads should be close together and maintained at the same temperature. The circuit shown in Figure 1 to measure offset voltage is also used as the burn-in configuration for the LT1124/ LT1125, with the supply voltages increased to ±16V. – VOUT W U UO + –15V 1124/25 F01 LT1124/LT1125 APPLICATI S I FOR ATIO High Speed Operation When the feedback around the op amp is resistive (RF), a pole will be created with RF, the source resistance and capacitance (RS, CS), and the amplifier input capacitance (CIN ≈ 2pF). In low closed loop gain configurations and with RS and RF in the kilohm range, this pole can create excess phase shift and even oscillation. A small capacitor (CF) in parallel with RF eliminates this problem (see Figure 2). With RS (CS + CIN) = RF CF, the effect of the feedback pole is completely removed. CF RF – RS CS CIN OUTPUT + 1124/25 F02 Figure 2. High Speed Operation Unity Gain Buffer Applications When R F ≤ 100Ω and the input is driven with a fast, large signal pulse (>1V), the output waveform will look as shown in Figure 3. RF – + OUTPUT 4.5V/µs 1124/25 F03 Figure 3. Unity-Gain Buffer Applications U During the fast feedthrough-like portion of the output, the input protection diodes effectively short the output to the input and a current, limited only by the output short circuit protection, will be drawn by the signal generator. With RF ≥ 500Ω, the output is capable of handling the current requirements (IL ≤ 20mA at 10V) and the amplifier stays in its active mode and a smooth transition will occur. Noise Testing Each individual amplifier is tested to 4.2nV/√Hz voltage noise; i.e., for the LT1124 two tests, for the LT1125 four tests are performed. Noise testing for competing multiple op amps, if done at all, may be sample tested or tested using the circuit shown in Figure 4. en OUT = √(enA)2 + (enB)2 + (enC)2 + (enD)2 If the LT1125 were tested this way, the noise limit would be √ 4 • (4.2nV/√Hz)2 = 8.4nV/√Hz. But is this an effective screen? What if three of the four amplifiers are at a typical 2.7nV/√Hz, and the fourth one was contaminated and has 6.9nV/√Hz noise? RMS Sum = √(2.7)2 + (2.7)2 + (2.7)2 + (6.9)2 = 8.33nV/√Hz This passes an 8.4nV/√Hz spec, yet one of the amplifiers is 64% over the LT1125 spec limit. Clearly, for proper noise measurement, the op amps have to be tested individually. – + A W U UO – + B – + C – + D OUT 1124/25 F04 Figure 4. Competing Quad Op Amp Noise Test Method 9 LT1124/LT1125 PERFOR A CE CO PARISO Table 2 summarizes the performance of the LT1124/ LT1125 compared to the low cost grades of alternate approaches. The comparison shows how the specs of the LT1124/ LT1125 not only stand up to the industry standard OP-27, Table 2. Guaranteed Performance, VS = ± 15V, TA = 25°C, Low Cost Devices PARAMETER/UNITS Voltage Noise, 1kHz Slew Rate Gain Bandwidth Product Offset Voltage Offset Current Bias Current Supply Current/Amp Voltage Gain, RL = 2k Common Mode Rejection Ratio Power Supply Rejection Ratio SO-8 Package LT1124 LT1125 LT1124 LT1125 LT1124CN8 LT1125CN 4.2 100% Tested 2.7 100% Tested 8.0 100% Tested 100 140 20 30 30 2.75 1.5 106 110 Yes - LT1124 OP-27 GP 4.5 Sample Tested 1.7 Not Tested 5.0 Not Tested 100 – 75 – 80 5.67 0.7 100 94 Yes OP-270 GP – No Limit 1.7 – No Limit 250 – 20 – 60 3.25 0.35 90 104 No OP-470 GP 5.0 Sample Tested 1.4 – No Limit – 1000 – 30 60 2.75 0.4 100 105 – UNITS nV/√Hz V/µs MHz µV µV nA nA nA mA V/µV dB dB TYPICAL APPLICATI S Gain Error vs Frequency Closed-Loop Gain = 1000 1.0 TYPICAL PRECISION OP AMP 0.1 Gain 1000 Amplifier with 0.01% Accuracy, DC to 1Hz 340k 1% 15k 5% 15V 2 20k TRIM 365Ω 1% – + 6 (S0-8) 8 (N8) 7 (SO-8) 1 (N8) OUTPUT 1/2 LT1124 3 4 –15V GAIN ERROR (PERCENT) RN60C FILM RESISTORS INPUT THE HIGH GAIN AND WIDE BANDWIDTH OF THE LT1124/LT1125, IS USEFUL IN LOW FREQUENCY HIGH CLOSED-LOOP GAIN AMPLIFIER APPLICATIONS. A TYPICAL PRECISION OP AMP MAY HAVE AN OPEN-LOOP GAIN OF ONE MILLION WITH 500kHz BANDWIDTH. AS THE GAIN ERROR PLOT SHOWS, THIS DEVICE IS CAPABLE OF 0.1% AMPLIFYING ACCURACY UP TO 0.3Hz ONLY. EVEN INSTRUMENTATION RANGE SIGNALS CAN VARY AT A FASTER RATE. THE LT1124/LT1125 “GAIN PRECISION — BANDWIDTH PRODUCT” IS 75 TIMES HIGHER, AS SHOWN. 1124/25 TA03 10 U but in most cases are superior. Normally dual and quad performance is degraded when compared to singles, for the LT1124/LT1125 this is not the case. LT1124/LT1125 0.01 GAIN ERROR = 0.001 0.1 CLOSED-LOOP GAIN OPEN-LOOP GAIN 100 1124/25 TA04 UO W UW 1 10 FREQUENCY (Hz) LT1124/LT1125 SCHE ATIC DIAGRA Q7 200pF 21k Q9 Q10 Q13 Q8 NONINVERTING INPUT (+) V– Q1A Q1B Q2B 67pF V+ V+ Q23 Q24 200µA 200µA 100µA 200Ω 6k 200Ω 6k 50Ω 20pF Q2A 400Ω Q30 INVERTING INPUT (–) Q3 W W (1/2 LT1124, 1/4 LT1125) V+ 360µA 570µA 100µA Q28 21k 3.6k 3.6k Q18 Q25 Q17 Q19 Q20 900Ω 20Ω Q26 35pF Q27 20Ω OUTPUT Q29 Q22 Q11 Q12 Q15 Q16 V– 1124/25 SS 11 LT1124/LT1125 PACKAGE DESCRIPTIO U Dimensions in inches (millimeters) unless otherwise noted. J8 Package 8-Lead CERDIP (Narrow 0.300, Hermetic) (LTC DWG # 05-08-1110) CORNER LEADS OPTION (4 PLCS) 0.005 (0.127) MIN 0.405 (10.287) MAX 8 7 6 5 0.023 – 0.045 (0.584 – 1.143) HALF LEAD OPTION 0.045 – 0.068 (1.143 – 1.727) FULL LEAD OPTION 0.300 BSC (0.762 BSC) 0.025 (0.635) RAD TYP 1 2 3 0.220 – 0.310 (5.588 – 7.874) 4 0.200 (5.080) MAX 0.015 – 0.060 (0.381 – 1.524) 0.008 – 0.018 (0.203 – 0.457) 0 ° – 1 5° NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE OR TIN PLATE LEADS 0.045 – 0.068 (1.143 – 1.727) 0.014 – 0.026 (0.360 – 0.660) 0.125 3.175 0.100 ± 0.010 MIN (2.540 ± 0.254) J8 1197 N8 Package 8-Lead PDIP (Narrow 0.300) (LTC DWG # 05-08-1510) 0.400* (10.160) MAX 8 7 6 5 0.255 ± 0.015* (6.477 ± 0.381) 1 0.300 – 0.325 (7.620 – 8.255) 2 3 4 0.130 ± 0.005 (3.302 ± 0.127) 0.045 – 0.065 (1.143 – 1.651) 0.009 – 0.015 (0.229 – 0.381) 0.065 (1.651) TYP 0.125 (3.175) 0.020 MIN (0.508) MIN 0.018 ± 0.003 (0.457 ± 0.076) N8 1197 ( +0.035 0.325 –0.015 8.255 +0.889 –0.381 ) 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) 12 LT1124/LT1125 PACKAGE DESCRIPTIO U Dimensions in inches (millimeters) unless otherwise noted. 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 6 5 0.228 – 0.244 (5.791 – 6.197) 0.150 – 0.157** (3.810 – 3.988) 1 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0°– 8° TYP 0.053 – 0.069 (1.346 – 1.752) 2 3 4 0.004 – 0.010 (0.101 – 0.254) 0.016 – 0.050 0.406 – 1.270 0.014 – 0.019 (0.355 – 0.483) 0.050 (1.270) TYP *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 SO8 0996 13 LT1124/LT1125 PACKAGE DESCRIPTIO U Dimensions in inches (millimeters) unless otherwise noted. J Package 14-Lead CERDIP (Narrow 0.300, Hermetic) (LTC DWG # 05-08-1110) 0.785 (19.939) MAX 14 13 12 11 10 9 8 0.005 (0.127) MIN 0.025 (0.635) RAD TYP 0.220 – 0.310 (5.588 – 7.874) 1 0.300 BSC (0.762 BSC) 2 3 4 5 6 7 0.200 (5.080) MAX 0.015 – 0.060 (0.381 – 1.524) 0.008 – 0.018 (0.203 – 0.457) 0° – 15° 0.045 – 0.068 (1.143 – 1.727) NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE OR TIN PLATE LEADS 0.014 – 0.026 (0.360 – 0.660) 0.100 ± 0.010 (2.540 ± 0.254) 0.125 (3.175) MIN J14 1197 N Package 14-Lead PDIP (Narrow 0.300) (LTC DWG # 05-08-1510) 0.770* (19.558) MAX 14 13 12 11 10 9 8 0.255 ± 0.015* (6.477 ± 0.381) 1 0.300 – 0.325 (7.620 – 8.255) 0.130 ± 0.005 (3.302 ± 0.127) 0.020 (0.508) MIN 0.009 – 0.015 (0.229 – 0.381) 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 1197 0.005 (0.125) MIN 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) ( +0.035 0.325 –0.015 8.255 +0.889 –0.381 ) 14 LT1124/LT1125 PACKAGE DESCRIPTIO U Dimensions in inches (millimeters) unless otherwise noted. SW Package 16-Lead Plastic Small Outline (Wide 0.300) (LTC DWG # 05-08-1620) 0.398 – 0.413* (10.109 – 10.490) 16 15 14 13 12 11 10 9 NOTE 1 0.394 – 0.419 (10.007 – 10.643) 0.291 – 0.299** (7.391 – 7.595) 0.010 – 0.029 × 45° (0.254 – 0.737) 0° – 8° TYP 1 2 3 4 5 6 7 8 0.093 – 0.104 (2.362 – 2.642) 0.037 – 0.045 (0.940 – 1.143) 0.009 – 0.013 (0.229 – 0.330) NOTE 1 0.016 – 0.050 (0.406 – 1.270) 0.050 (1.270) TYP 0.004 – 0.012 (0.102 – 0.305) NOTE: 1. PIN 1 IDENT, NOTCH ON TOP AND CAVITIES ON THE BOTTOM OF PACKAGES ARE THE MANUFACTURING OPTIONS. THE PART MAY BE SUPPLIED WITH OR WITHOUT ANY OF THE OPTIONS *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 0.014 – 0.019 (0.356 – 0.482) TYP S16 (WIDE) 0396 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. 15 LT1124/LT1125 TYPICAL APPLICATION Strain Gauge Signal Conditioner with Bridge Excitation 15V 5k 3 2.5V LT1009 2 1k + 1/4 LT1125 1 – –15V 350Ω BRIDGE 15V 13 – 1/4 LT1125 14 1k *RN60C FILM RESISTORS –15V 12 + RELATED PARTS PART NUMBER LT1007 LT1028/LT1128 LT1112/LT1114 LT1113 LT1126/LT1127 LT1169 LT1792 LT1793 DESCRIPTION Single Low Noise, Precision Op Amp Single Low Noise, Precision Op Amps Dual/Quad Precision Picoamp Input Dual Low Noise JFET Op Amp Decompensated LT1124/LT1125 Dual Low Noise JFET Op Amp Single LT1113 Single LT1169 COMMENTS 2.5nV/√Hz 1kHz Voltage Noise 0.85nV/√Hz Voltage Noise 250pA Max IB 4.5nV/√Hz Voltage Noise, 10fA/√Hz Current Noise 11V/µs Slew Rate 6nV/√Hz Voltage Noise, 1fA/√Hz Current Noise, 10pA Max IB 4.2nV/√Hz Voltage Noise, 10fA/√Hz Current Noise 6nV/√Hz Voltage Noise, 1fA/√Hz Current Noise, 10pA Max IB 16 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408)432-1900 q FAX: (408) 434-0507 q www.linear-tech.com U THE LT1124/LT1125 IS CAPABLE OF PROVIDING EXCITATION CURRENT DIRECTLY TO BIAS THE 350Ω BRIDGE AT 5V WITH ONLY 5V ACROSS THE BRIDGE (AS OPPOSED TO THE USUAL 10V) TOTAL POWER DISSIPATION AND BRIDGE WARM-UP DRIFT IS REDUCED. THE BRIDGE OUTPUT SIGNAL IS HALVED, BUT THE LT1124/LT1125 CAN AMPLIFY THE REDUCED SIGNAL ACCURATELY. REFERENCE OUTPUT 15V 5 301k* 10k ZERO TRIM + – 4 1/4 LT1125 13 –15V 50k GAIN TRIM 499Ω* 7 0V TO 10V OUTPUT 1µF 301k* 6 1124/25 TA05 11245fas, sn11245 LT/TP 0699 REV A 2K • PRINTED IN USA © LINEAR TECHNOLOGY CORPORATION 1992