LT1077 Micropower, Single Supply, Precision Op Amp U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO 60µA Max Supply Current 40µV Max Offset Voltage 350pA Max Offset Current 0.5µVP-P 0.1Hz to 10Hz Voltage Noise 2.5pAP-P 0.1Hz to 10Hz Current Noise O.4µV/°C Offset Voltage Drift 250kHz Gain-Bandwidth Product 0.12V/µs Slew Rate Single Supply Operation Input Voltage Range Includes Ground Output Swings to Ground while Sinking Current No Pull-Down Resistors are Needed Output Sources and Sinks 5mA Load Current U APPLICATIO S ■ ■ ■ ■ ■ Replaces OP-07, OP-77, AD707, LT1001, LT1O12 at 10 to 60 Times Lower Power Battery or Solar Powered Systems 4mA to 2OmA Current Loops Two Terminal Current Source Megaohm Source Resistance Difference Amplifier , LTC and LT are registered trademarks of Linear Technology Corporation. The LT®1077 is a micropower precision operational amplifier optimized for single supply operation at 5V. In addition, ±15V specifications are provided. Micropower performance of competing devices is achieved at the expense of seriously degrading precision, noise, speed, and output drive specifications. The LT1077 reduces supply current without sacrificing other parameters. The offset voltage achieved is the lowest of any micropower op amp. Offset current, voltage and current noise, slew rate and gain-bandwidth product are all two to ten times better than on previous micropower op amps. The 1/f corner of the voltage noise spectrum is at 0.7Hz. This results in low frequency (0.1Hz to 10Hz) noise performance which can only be found on devices with an order of magnitude higher supply current. The LT1077 is completely plug-in compatible (including nulling) with all industry standard precision op amps. Thus, it can replace these precision op amps in many applications without sacrificing performance, yet with significant power savings. The LT1077 can be operated from one lithium cell or two Ni-Cad batteries. The input range goes below ground. The all-NPN output stage swings to ground while sinking current—no pull-down resistors are needed. For dual and quad op amps with similar specifications please see the LT1078/LT1079 datasheet. U TYPICAL APPLICATIO Distribution of Input Offset Voltage 35 Self Buffered Micropower Reference 30 – 7 LT1077 3 0.1µF 750k + 6 4 LT1034 1.2V OUTPUT 1.230V ±1.2% MAX SUPPLY CURRENT = 60µA MAX SOURCES UP TO 10mA LOAD REGULATION = 30µV/mA TEMPERATURE DRIFT = 12ppm/°C LT1077 • TA01 PERCENT OF UNITS 3.6V TO 9V 2 25 20 VS = 5V, 0V TA = 25°C 1072 UNITS TESTED IN H, J8, N8 PACKAGES 15 10 5 0 0 –40 –30 –20 –10 10 20 30 40 INPUT OFFSET VOLTAGE (µV) LT1077 • TA02 1077fa 1 LT1077 W W W AXI U U ABSOLUTE RATI GS (Note 1) Operating Temperature Range LT1077AM/LT1077M (OBSOLETE).... – 55°C to 125°C LT1077AI/LT1077I.............................. – 40°C to 85°C LT1077AC/LT1077C/LT1077S8 ............... 0°C to 70°C Storage Temperature Range ................. – 65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C Supply Voltage ...................................................... ±22V Differential Input Voltage ....................................... ±30V Input Voltage ............... Equal to Positive Supply Voltage Input Voltage ............5V Below Negative Supply Voltage Output Short-Circuit Duration .......................... Indefinite U U W PACKAGE/ORDER I FOR ATIO TOP VIEW VOS TRIM 8 A –IN 2 +IN 3 – TOP VIEW 7 V+ VOS TRIM 1 B + + 6 OUT – 5 NC 4 V– H PACKAGE 8-LEAD TO-5 METAL CAN TJMAX = 150°C, θJA = 150°C/W, θJC = 45°C/W ORDER PART NUMBER LT1077AMH LT1077MH LT1077ACH LT1077CH TOP VIEW VOS TRIM 1 8 VOS TRIM VOS TRIM 1 8 VOS TRIM –IN 2 7 V+ –IN 2 7 V+ +IN 3 6 OUT +IN 3 6 OUT 5 NC V – 4 5 V– NC J8 PACKAGE 8-LEAD CERDIP TJMAX = 150°C, θJA = 100°C/W ORDER PART NUMBER LT1077AMJ8 LT1077MJ8 LT1077ACJ8 LT1077CJ8 OBSOLETE PACKAGE Consider the N8 or S8 Package for Alternate Source 4 N8 PACKAGE 8-LEAD PDIP TJMAX = 100°C, θJA = 130°C/W S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 190°C/W ORDER PART NUMBER LT1077S8 LT1077IS8 LT1077AIN8 LT1077IN8 LT1077ACN8 LT1077CN8 S8 PART MARKING 1077 1077I LT1077 • POI01 Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER VOS Input Offset Voltage VS = 5V, 0V, VCM = 0.1V, VO = 1.4V, TA = 25°C unless noted. CONDITIONS LT1077AM/AI/AC MIN TYP MAX 9 40 LT1077S8 MIN LT1077M/I/C/S8 TYP MAX 10 12 60 150 µV µV ∆VOS ∆Time Long Term Input Offset Voltage Stability 0.4 IOS Input Offset Current 0.06 0.35 0.06 0.45 nA IB Input Bias Current 7 9 7 11 nA en Input Noise Voltage 0.1Hz to 10Hz (Note3) 0.5 1.1 0.5 µVP-P Input Noise Voltage Density fO = 10Hz (Note 3) fO = 1000Hz (Note3) 28 27 43 35 28 27 nV/√Hz nV/√Hz Input Noise Current 0.1Hz to 10Hz (Note3) 2.5 4.5 2.5 pAP-P in 0.4 UNITS µV/Mo 1077fa 2 LT1077 ELECTRICAL CHARACTERISTICS SYMBOL VS = 5V, 0V, VCM = 0.1V, VO = 1.4V, TA = 25°C unless noted. PARAMETER CONDITIONS Input Noise Current Density fO = 10Hz (Note 3) fO = 1000Hz Input Resistance Differential Mode Common Mode (Note 4) Input Voltage Range LT1077AM/AI/AC MIN TYP MAX 0.065 0.02 MIN LT1077M/I/C/S8 TYP MAX 0.11 0.065 0.02 UNITS pA/√Hz pA/√Hz 350 700 6 270 700 6 MΩ GΩ 3.5 0 3.8 – 0.3 3.5 0 3.8 – 0.3 V V CMRR Common Mode Rejection Ratio VCM = 0V to 3.5V 97 106 94 105 dB PSRR Power Supply Rejection Ratio VS = 2.3V to 12V 102 118 100 117 dB AVOL Large-Signal Voltage Gain VO = 0.03V to 4V, No Load VO = 0.03V to 3.5V, RL = 50k 300 250 1000 1000 240 200 1000 1000 V/mV V/mV Maximum Output Voltage Swing Output Low, No Load Output Low, 2k to GND Output Low, lSINK = 100µA Output High, No Load Output High, 2k to GND 4.2 3.5 3.5 0.7 90 4.4 3.9 4.2 3.5 3.5 0.7 90 4.4 3.9 0.05 0.08 0.05 0.08 V/µs 230 kHz SR Slew Rate (Note 2) GBW Gain Bandwidth Product fO ≤ 20kHz IS Supply Current 6 1.1 130 230 48 = 10k, Wiper to V+ Offset Adjustment Range Rpot Minimum Supply Voltage (Note 5) ±500 60 48 ±900 ±500 2.2 6 1.1 130 2.3 68 ±900 2.2 mV mV mV V V µA µV 2.3 V The ● denotes the specifications which apply over the temperature range of –55°C ≤ TA ≤ 125°C for AM/M grades, –40°C ≤ TA ≤ 85°C for AI/I grades. VS = 5V, 0V, VCM = 0.1V, VO = 1.4V unless otherwise noted. VOS Input Offset Voltage ∆VOS/∆T Input Offset Voltage Drift IOS Input Offset Current ● 0.08 IB Input Bias Current ● 8 CMRR Common Mode Rejection Ratio VCM = 0.05V to 3.2V ● 92 104 88 103 dB PSRR Power Supply Rejection Ratio VS = 3.1V to 12V ● 98 114 94 113 dB AVOL Large-Signal Voltage Gain VO = 0.05V to 3.5V, RL = 50k ● 120 600 100 600 V/mV Maximum Output Voltage Swing Output Low, No Load Output Low, ISINK = 100µA Output High, No Load Output High, 2k to GND ● ● ● ● 8 170 3.9 3 4.5 120 4.2 3.7 8 170 3.9 3 4.5 120 4.2 3.7 mV mV V V 54 80 54 90 µA Supply Current MIN 50 ● LT1077IS8 (Note 6) MIN LT1077M/I TYP MAX PARAMETER IS CONDITIONS LT1077AM/AI TYP MAX SYMBOL 200 60 260 µV 1 2.5 µV/°C 0.60 0.08 0.80 nA 11 8 13 nA ● ● UNITS 1077fa 3 LT1077 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the temperature range of 0°C ≤ TA ≤ 70°C otherwise, specifications are at TA = 25°C. VS = 5V, 0V, VCM = 0.1V, VO = 1.4V unless noted. SYMBOL PARAMETER VOS Input Offset Voltage CONDITIONS LT1077S8 LT1077AC TYP MAX MIN LT1077C/S8 TYP MAX UNITS ● ● 30 110 35 40 150 280 µV µV ● 0.4 1.6 0.5 0.7 2.0 3.0 µV/°C µV/°C ∆VOS/∆T Input Offset Voltage Drift IOS Input Offset Current ● 0.07 0.45 0.07 0.60 nA IB Input Bias Current ● 7 10 7 12 nA CMRR Common Mode Rejection Ratio VCM = 0V to 3.4V ● 94 105 90 104 dB PSRR Power Supply Rejection Ratio VS = 2.6V to 12V ● 100 116 97 115 dB AVOL Large-Signal Voltage Gain VO = 0.05V to 3.5V, RL = 50k ● 180 800 150 800 V/mV Maximum Output Voltage Swing Output Low, No Load Output Low, ISINK = 100µA Output High, No Load Output High, 2k to GND ● ● ● ● 7 150 4.1 3.3 4.0 100 4.3 3.8 7 150 4.1 3.3 4.0 100 4.3 3.8 mV mV V V 52 70 52 80 µA IS (Note 6) LT1077S8 (Note 6) MIN Supply Current ● VS = ±15V, TA = 25°C unless noted. SYMBOL PARAMETER VOS Input Offset Voltage CONDITIONS LT1077AM/AI/AC MIN TYP MAX MIN LT1077M/I/C/S8 TYP MAX 20 150 25 30 200 300 µV µV 0.06 0.35 0.06 0.45 nA 7 9 7 11 nA LT1077S8 IOS Input Offset Current IB Input Bias Current Input Voltage Range UNITS 13.5 – 15.0 13.8 – 15.3 13.5 – 15.0 13.8 – 15.3 V V CMRR Common Mode Rejection Ratio VCM = 13.5V to –15V 100 109 97 108 dB PSRR Power Supply Rejection Ratio VS = 5V, 0V to ±18V 106 122 103 120 dB AVOL Large-Signal Voltage Gain VO = ±10V, RL = 50k VO = ±10V, RL = 2k 1000 400 8000 1500 800 300 8000 1500 V/mV V/mV VOUT Maximum Output Voltage Swing RL = 50k RL = 2k ±13.0 ±11.0 ±14.0 ±13.2 ±13.0 ±11.0 ±14.0 ±13.2 V V SR Slew Rate 0.07 0.12 0.07 0.12 V/µs IS Supply Current 56 75 56 85 µA 1077fa 4 LT1077 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the temperature range of –55°C ≤ TA ≤ 125°C for AM/M grades, – 40°C ≤ TA ≤ 85°C for AI/I grades. VS = ±15V unless otherwise noted. MIN VOS Input Offset Voltage ∆VOS/∆T Input Offset Voltage Drift IOS Input Offset Current ● 0.08 IB Input Bias Current ● 8 AVOL Large-Signal Voltage Gain VO = ±10V, RL = 5k ● 300 1000 250 1000 V/mV CMRR Common Mode Rejection Ratio VCM = 13V, –14.9V ● 94 107 90 106 dB PSRR Power Supply Rejection Ratio VS = 5V, 0V to ±18V ● 100 118 97 116 dB Maximum Output Voltage Swing RL = 5k ● ±11 ±13.5 ±11 ±13.5 V 60 ● LT1077IS8 (Note 6) Supply Current MIN LT1077M/I TYP MAX PARAMETER IS CONDITIONS LT1077AM/AI TYP MAX SYMBOL 330 75 450 1.1 3 0.60 0.08 0.80 nA 11 8 13 nA ● 60 ● UNITS 95 60 µV µV/°C 105 µA LT1077C/S8 TYP MAX UNITS The ● denotes the specifications which apply over the temperature range of 0°C ≤ TA ≤ 70°C. VS = ±15V unless otherwise noted. SYMBOL PARAMETER VOS Input Offset Voltage CONDITIONS MIN LT1077AC TYP MAX MIN ● ● 40 230 LT1077S8 50 65 320 450 µV µV (Note 6) LT1077S8 (Note 6) ● ● 0.4 1.8 0.5 0.8 2.5 3.5 µV/°C µV/°C ∆VOS/∆T Input Offset Voltage Drift IOS Input Offset Current ● 0.07 0.45 0.07 0.60 nA IB Input Bias Current ● 7 10 7 12 nA AVOL Large-Signal Voltage Gain VO = ±10V, RL = 5k ● 500 2000 400 2000 V/mV CMRR Common Mode Rejection Ratio VCM = 13V, –15V ● 97 108 94 107 dB PSRR Power Supply Rejection Ratio VS = 5V, 0V to ±18V ● 103 120 100 118 dB Maximum Output Voltage Swing RL = 5k ● ±11 ±13.6 ±11 ±13.6 V IS Supply Current Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impared. Note 2: Slew rate at 5V, 0V is guaranteed by inference from the slew rate measurement at ±15V. Note 3: This parameter is tested on a sample basis only. All noise parameters are tested with VS = ± 2.5V, VO = 0V. ● 59 85 59 95 µA Note 4: This parameter is guaranteed by design and is not tested. Note 5: Power supply rejection ratio is measured at the minimum supply voltage. The op amps actually work at 1.8V supply but with a typical offset skew of – 300µV. Note 6: This parameter is not 100% tested. 1077fa 5 LT1077 U W TYPICAL PERFOR A CE CHARACTERISTICS Input Bias and Offset Currents vs Temperature VS = ±15V VS = 5V, 0V –1 40 50 25 75 0 TEMPERATURE (˚C) –50 –25 100 125 VS = 5V, 0V VS = 5V, 0V TO ±15V 100 –3 IOS 75 50 50 BIAS CURRENT (nA) SUPPLY CURRENT (µA) 60 Input Bias Currents vs Common Mode Voltage INPUT BIAS CURRENT (nA) OFFSET CURRENT (pA) Supply Current vs Temperature –6 IB –7 –5 TA = 25°C TA = 55°C –7 TA = 125°C –9 –11 –8 –50 –25 50 25 0 75 TEMPERATURE (°C) 100 –13 –1 125 4 0 1 2 3 COMMON MODE VOLTAGE (V) LT1077 • TPC03 LT1077 • TPC01 LT1077 • TPC02 0.01Hz to 10Hz Noise 0.1Hz to 10Hz Noise 8 0 10 20 LT1077 • TPC04 VS = ± 2.5V TA = 2.5°C 30 PERCENT OF UNITS 25 20 15 10 CURRENT NOISE VOLTAGE NOISE 30 1/f CORNER 0.7Hz 10 0.1 100 VS = 5V, 0V VCM = 0.1V 1 1000 Distribution of Input Offset Voltage in Small Outline (S8) Package 70 10 10 100 FREQUENCY (Hz) LT1077 • TPC06 400 UNITS TESTED (100 IN EACH PACKAGE) 20 VS = ± 2.5V TA = 25°C (AT VS = ±15V VOLTAGE NOISE IS 4% LESS CURRENT NOISE IS UNCHANGED 100 Distribution of Offset Voltage Drift with Temperature (In All Packages) 35 PERCENT OF UNITS 80 300 LT1077 • TPC05 10Hz Voltage Noise Distribution 30 60 40 TIME (SECONDS) 60 PERCENT OF UNITS 6 4 TIME (SECONDS) 0.4µV NOISE VOLTAGE (0.4µV/DIV) NOISE VOLTAGE (0.4µV/DIV) 2 VOLTAGE NOISE DENSITY (nV/√Hz) CURRNET NOISE DENSITY (fA/√Hz) VS = ± 2.5V TA = 2.5°C VS = ± 2.5V TA = 2.5°C 0 Noise Spectrum 1000 VS = 5V, 0V TA = 25°C 456 UNITS TESTED 50 40 30 20 10 5 0 0 25 35 30 VOLTAGE NOISE DENSITY (nV/√Hz) 40 LT1077 • TPC07 –1.0 1.0 2.0 0 –2.0 OFFSET VOLTAGE DRIFT WITH TEMPERATURE (nV/°C) LT1077 • TPC08 0 –150 –120 –90 –60 –30 0 30 60 90 120 150 INPUT OFFSET VOLTAGE (µV) LT1077 • TPC09 1077fa 6 LT1077 U W TYPICAL PERFOR A CE CHARACTERISTICS Voltage Gain vs Frequency VS = 5V, 0V 5V, 0V GAIN 10 ±15V 140 PHASE MARGIN 54° 160 ±15V 180 5V, 0V 0 20 200 TA = 25°C CL = 20pF 0 1 –10 10k 10 100 1k 10k 100k 1M FREQUENCY (Hz) 30k 100k 300k FREQUENCY (Hz) 70 φM ±15V 60 50 GBW ±15V 40 220 180 –50 –25 10 100 1000 CAPACITIVE LOAD (pF) 10,000 LT1077 • TPC12 Large-Signal Transient Response VS = ±15V 25 50 0 75 TEMPERATURE (°C) 100 0V 0V 100µs/DIV GBW 5V, 0V 200 125 50µs/DIV AV = 1 NO LOAD INPUT PULSE 0V TO 3.8V AV = 1 NO LOAD Small-Signal Transient Response VS = ± 2.5V Small-Signal Transient Response VS = ±15V 0.1V AV = 1 10µs/DIV CL = 15pF INPUT 50mV TO 150mV 20mV/DIV Small-Signal Transient Response VS = 5V, 0V 0V AV = 1 CL = 15pF 10µs/DIV 20mV/DIV LT1077 • TPC13 20mV/DIV GAIN BANDWIDTH PRODUCT (kHz) φM ±5V, 0V 260 240 0 1M 1V/DIV 80 0.08 0.06 AV = 10 AV = 5 SLEW ±15V SLEW 5V, 0V 0.10 40 Large-Signal Transient Response VS = 5V, 0V PHASE MARGIN (DEGREES) SLEW RATE (V/µs) fO = 20kHz AV = 1 60 LT1077 • TPC11 Slew Rate, Gain Bandwidth Product and Phase Margin vs Temperature 0.12 80 20 LT1077 • TPC10 0.14 VS = 5V, 0V TA = 25°C 5V/DIV –20 0.01 0.1 OVERSHOOT (%) 60 100 120 PHASE SHIFT (DEGREES) VS = ±15V 80 100 PHASE 20 VOLTAGE GAIN (dB) VOLTAGE GAIN (dB) 100 120 PHASE MARGIN 66° TA = 25°C 120 40 Capacitive Load Handling Gain, Phase vs Frequency 30 140 0V AV = 1 CL = 15pF 10µs/DIV 1077fa 7 LT1077 U W TYPICAL PERFOR A CE CHARACTERISTICS Minimum Supply Voltage Warm-Up Drift 0.8 –200 0°C –300 –55°C 25°C –400 0.4 0.2 0 –500 0 2 3 1 POSITIVE SUPPLY VOLTAGE (V) 1 0 2 125°C OUTPUT VOLTAGE SWING (V) SATURATION VOLTAGE (mV) ISINK = 100µA ISINK = 10µA ISINK = 1µA 10 NO LOAD V+ – 1 0 25 50 75 100 –55°C 125°C 25°C 0.1 1 TA = 25°C, VS = ±15V 10 TA = 125°C, VS = 5V, 0V 0 –10 TA = 125°C, VS = ±15V –20 PEAK-TO-PEAK OUTPUT SWING, VS = ±15V (V) V+ – 2 V– + 1 V– 100 125 LT1077 • TPC25 TA = 25°C, VS = ±15V LT1077 • TPC24 Undistorted Output Swing vs Frequency V+ – 1 TA = 125°C, VS = ±15V LT1077 • TPC23 30 Closed Loop Output Impedance TA = 25°C LOAD RL, TO GROUND 5 VS = 5V, 0V, RL ≥ 100k 20 4 VS = ±15V RL ≥ 100k VS = 5V, 0V RL ≥ 1k 3 2 10 1 VS = ±15V RL = 30k 0 100 1k 10k FREQUENCY (Hz) 0 100k LT1077 • TPC26 PEAK-TO-PEAK OUTPUT SIWNG, VS = 5V, 0V (V) COMMON MODE RANGE (V) 20 1 2 3 0 TIME FROM OUTPUT SHORT TO GROUND (MINUTES) SOURCING OR SINKING LOAD CURRENT (mA) Common Mode Range vs Temperature 50 25 0 75 TEMPERATURE (°C) TA = 25°C, VS = 5V, 0V –40 10 LT1077 • TPC22 V– – 1 – 50 –25 30 –30 –55°C V– 0.01 1M 40 25°C V– + 1 125 V + = 2.5V TO 18V V – = 0V TO –18V 10k 1k 100k LOAD RESISTANCE TO GROUND (Ω) Short-Circuit Current vs Time V– + 2 TEMPERATURE (°C) V+ 4. –55°C 5. 25°C VS = 5V, 0V 6. 125°C LT1077 • TPC21 V+ – 2 RL = 5k TO GROUND 0 –50 –25 6 Output Voltage Swing vs Load Current V+ 100 4 LT1077 • TPC20 ISINK = 2mA ISINK = 1mA 2 5 TIME AFTER POWER ON (MINUTES) Output Saturation vs Temperature vs Sink Current VS = 5V, 0V 1 1M 100k 100 3 LT1077 • TPC19 1000 1. 25°C 2. –55°C VS = ±15V 3. 125°C 3 VOLTAGE GAIN (V/V) –100 WARM UP DRIFT 0.6 AT VS = 5V, 0V IS IMMEASURABLY LOW SHORT-CIRCUIT CURRENT (mA) SINKING SOURCING INPUT OFFSET VOLTAGE (µV) 125°C NON FUNCTIONAL VS = ±15V TA = 25°C 70°C 0 Voltage Gain vs Load Resistance 10M 1k OUTPUT IMPEDANCE (Ω) V – = 0V – 0.1 ≤ VCM ≤ 0.4V CHANGE IN OFFSET VOLTAGE (µV) 100 AV = 100 100 10 AV = 1 AV = 10 1 0.1 10 10k 100 1k FREQUENCY (Hz) 100k LT1077 • TPC27 1077fa 8 LT1077 U W TYPICAL PERFOR A CE CHARACTERISTICS Common Mode Rejection Ratio vs Frequency 120 120 TA = 25°C POWER SUPPLY REJECTION RATIO (dB) COMMON MODE REJECTION RATIO (dB) Power Supply Rejection Ratio vs Frequency 100 VS = ±15V 80 VS = 5V, 0V 60 40 20 100 1k 10k FREQUENCY (Hz) 100k 80 60 NEGATIVE SUPPLY 40 20 VS = ± 2.5V + 1VP-P SINE WAVE TA = 25°C 0 0.1 0 10 POSITIVE SUPPLY 100 1M 1 10 100 1k 10k FREQUENCY (Hz) 100k LT1077 • TPC29 LT1077 • TPC28 U W U U APPLICATIO S I FOR ATIO The LT1077 is fully specified with V+ = 5V, V – = 0V, VCM = 0.1V. This set of operating conditions appears to be the most representative for battery powered micropower circuits. Offset voltage is internally trimmed to a minimum value at these supply voltages. When 9V or 3V batteries, or ±2.5V dual supplies are used, bias and offset current changes will be minimal. Offset voltage changes will be just a few microvolts as given by the PSRR and CMRR specifications. For example, if PSRR = 114dB ( = 2µV/V), at 9V the offset voltage change will be 8µV. Similarly, VS ±2.5V, VCM = 0 is equivalent to a common mode voltage change of 2.4V or a V OS change of 7µV if CMRR = 110dB (3µV/V). A full set of specifications is also provided at ±15V supply voltages for comparison with other devices and for completeness. The LT1077 is pin compatible to, and directly replaces, such precision op amps as the OP-07, OP-77, AD7O7 and LT1001 with 30 to 60 times savings in supply current. The LT1077 is also a direct plug-in replacement for LT1012 and OP-97 devices with 10 times lower dissipation. Compatibility includes externally nulling the offset voltage, as all of the devices above are trimmed with a potentiometer between Pins 1 and 8 and the wiper tied to V+. The LT1077 replaces and upgrades such micropower op amps as the OP-20, LM4250, and OP-90, provided that the external nulling circuitry (and set resistor in the case of the LM4250) are removed. Since the offset voltage of the LT1077 is extremely low, nulling will be unnecessary in most applications. Single Supply Operation The LT1077 is fully specified for single supply operation, (i.e., when the negative supply is 0V). Input common mode range goes below ground and the output swings within a few millivolts of ground while sinking current. All competing micropower op amps either cannot swing to within 600mV of ground (OP-20, OP-220, OP-420) or need a pull-down resistor connected to the output to swing to ground (OP-90, OP-290, OP-490, HA5141/42/ 44). This difference is critical because in many applications these competing devices cannot be operated as micropower op amps and swing to ground simultaneously. Consider the difference amplifiers shown in Typical Applications as an example. When the common mode signal is high and the output low, the amplifier has to sink current. In the gain of 10 circuit, the competing devices require a 30k pull-down resistor at the output to handle the specified signals. (The LT1077 does not need pull-down 1077fa 9 LT1077 U W U U APPLICATIO S I FOR ATIO resistors.) When the output is high the pull-down resistor draws 80µA which dominates the micropower current budget. This situation is much worse in the gain of one circuit with V –=0V. At 100V common mode, the output has to sink 2µA. At a minimum output voltage of 20mV competing devices require a 10k pull-down resistor. As the output now swings to 10V, this resistor draws 1mA of current. Since the output of the LT1077 cannot go exactly to ground, but can only approach ground to within a few millivolts, care should be exercised to ensure that the output is not saturated. For example, a 1mV input signal will cause the amplifier to set up in its linear region in the gain 100 configuration shown below; however, it is not enough to make the amplifier function properly in the voltage follower mode. Gain 100 Amplifier Voltage Follower 5V R – + b) When the input is more than 400mV below ground (at 25°C), the input stage saturates and phase reversal occurs at the output (this can cause lock-up in servo systems). Due to a unique phase reversal protection circuitry, the LT1077’s output does not reverse, as illustrated below, even when the input is at – 1.0V. OUTPUT SATURATED ≈ 3.5mV 100mV 1mV a) When the input is more than a diode drop below ground, unlimited current will flow from the substrate (V – terminal) to the input (this can destroy the unit). On the LT1077, resistors in series with the input protect the device even when the input is 5V below ground. 5V 99R – Single supply operation can also create difficulties at the input. The driving signal can fall below 0V—inadvertently or on a transient basis. If the input is more than a few hundred millivolts below ground, two distinct problems can occur on previous single supply designs, such as the LM124, LM158, OP-20, OP-21, OP-220, OP-221, OP-420 (a and b), OP-90/290/490 (b only): 1mV + LT1077 • AI01 Voltage Follower with Input Exceeding the Negative Common Mode Range (VS = 5V, 0V) 4V 4V 4V 2V 2V 2V 0 0 0 6VP-P INPUT –1.0 TO 5.0V 1ms/DIV OP-90 1ms/DIV EXHIBITS OUTPUT PHASE REVERSAL LT1077 1ms/DIV NO PHASE REVERSAL 1077fa 10 LT1077 U W U U APPLICATIO S I FOR ATIO The single supply operation of the LT1077 and its ability to swing close to ground while sinking current, lends itself to use as a precision comparator with TTL compatible output. Comparator Rise Response Time to 10mV, 5mV, 2mV Overdrive Comparator Fall Response Time to 10mV, 5mV, 2mV Overdrive OUTPUT (V) 4 OUTPUT (V) 4 INPUT (mV) 0 0 INPUT (mV) Comparator Applications 0 100 2 –100 200µs/DIV 0 VS = 5V, 0V 200µs/DIV U VS = 5V, 0V 2 TYPICAL APPLICATIO S Megaohm Input Impedance Gain of 10 Difference Amplifier 10M – 1M 2 1M 3 3V 7 6 INPUT + OUTPUT 0.005 TO 2.4V 4 10M BANDWIDTH = 20KHZ OUTPUT OFFSET = 0.7mV OUTPUT NOISE = 80µVPP (0.1Hz TO 10Hz) 260µVRMS OVER FULL BANDWIDTH SUPPLY CURRENT = 45µA THE USEFULNESS OF DIFFERENCE AMPLIFIERS IS LIMITED BY THE FACT THAT THE INPUT RESISTANCE IS EQUAL TO THE SOURCE RESISTANCE. THE PICO-AMPERE OFFSET CURRENT AND LOW CURRENT NOISE OF THE LT1077 ALLOWS THE USE OF 1M SOURCE RESISTORS WITHOUT DEGRADATION IN PERFORMANCE. IN ADDITION, WITH MEGAOHM RESISTORS MICROPOWER OPERATION CAN BE MAINTAINED LT1077 • TA03 1077fa 11 LT1077 U TYPICAL APPLICATIO S ±250V Common Mode Range Difference Amplifier (AV = 1) R1 1M R5 975k – IN 3 4 1 R2 20k 3V TO 18V 2 COMMON MODE INPUT ± 250V 7 6 OPTIONAL CMRR TRIM 2 6 R3 1M + IN 7 50k R6 25k OUT 3 4 R4 19.608k 5 OV TO –18V R1 TO R6: VISHAY 444 ACCUTRACT THIN FILM SIP NETWORK X :VISHAY 444 PIN NUMBERS VISHAY INTERTECHNOLOGY, INC. 63 LINCOLN HIGHWAY MALVERN, PA 19355 COMMON MODE REJECTION RATIO = 74dB (RESISTOR LIMITED) WITH OPTIONAL TRIM = 108dB OUTPUT OFFSET (TRIMMABLE TO ZERO) = 500µV OUTPUT OFFSET DRIFT = 25µV/°C INPUT RESISTANCE = 1M COMMON MODE RANGE = ± 250V, V + = 6.2V TO 18V, V – = –4.7V TO –18V = ± 100V, V ++≥ 3.2V, V – ≤ –1.8V LT1077 • TA04 = 100V, –13V, V + ≥ 3.2V, V – = 0V Two Terminal Current Source Half-Wave Rectifier 2M 3.6V TO 40V 2 – 7 1M 6 LT1077 3 + INPUT 1M 4 IS 750k + VR1 – R1 3V – LT1077 + V0MIN = 6mV NO DISTORTION TO 100Hz 1.8V 1.8V –1.8V LT1034 1.2V OUTPUT 0 LT1077 • TA06 LT1077 • TA05 IO RL IO = = VR1 + IS R1 1.230V + 50µA R1 MINIMUM CURRENT = 50µA (R1 → ∞) MAXIMUM CURRENT = 10.3mA (R1 = 120Ω) 1077fa 12 +IN –IN 600Ω 600Ω NULL Q5 Q21 Q1 9k 700Ω Q9 Q22 Q2 Q1 Q6 9k NULL C2 175pF 700Ω Q7 6.2k 1 4 Q12 V+ Q39 Q28 Q27 Q3 Q16 2.2k 8.6k Q24 6.2k Q8 Q4 Q14 Q15 Q18 Q10 Q17 C5 2.5pF C1 50pF Q29 5.6k Q19 1.3k Q20 C3 40pF Q37 Q32 1.35k 2.9k Q34 Q23 Q31 Q25 3 Q30 C4 4pF 1 3.6k 3k Q26 Q36 30Ω 10k OUT 30Ω Q35 1 1 LT1077 • S01 Q38 V+ 150k Q33 Q54 5k Q50 Q47 2 Q53 Q45 11.5k Q42 V– Q46 5.35k Q51 Q55 Q44 V+ V+ Q43 Q48 9.1k Q40 Q41 Q49 J1 Q52 12.5k 700k 700k W W SI PLIFIED SCHE ATIC V– LT1077 1077fa 13 LT1077 U PACKAGE DESCRIPTIO H Package 8-Lead TO-5 Metal Can (.200 Inch PCD) (Reference LTC DWG # 05-08-1320) .335 – .370 (8.509 – 9.398) DIA .305 – .335 (7.747 – 8.509) .027 – .045 (0.686 – 1.143) PIN 1 45°TYP .028 – .034 (0.711 – 0.864) .040 (1.016) MAX .050 (1.270) MAX SEATING PLANE .200 (5.080) TYP .165 – .185 (4.191 – 4.699) GAUGE PLANE .010 – .045* (0.254 – 1.143) REFERENCE PLANE .500 – .750 (12.700 – 19.050) .016 – .021** (0.406 – 0.533) .110 – .160 (2.794 – 4.064) INSULATING STANDOFF *LEAD DIAMETER IS UNCONTROLLED BETWEEN THE REFERENCE PLANE AND THE SEATING PLANE .016 – .024 **FOR SOLDER DIP LEAD FINISH, LEAD DIAMETER IS (0.406 – 0.610) H8(TO-5) 0.200 PCD 0801 J8 Package 8-Lead CERDIP (Narrow .300 Inch, Hermetic) (Reference LTC DWG # 05-08-1110) CORNER LEADS OPTION (4 PLCS) .023 – .045 (0.584 – 1.143) HALF LEAD OPTION .045 – .068 (1.143 – 1.650) FULL LEAD OPTION .005 (0.127) MIN .405 (10.287) MAX 8 7 6 5 .025 (0.635) RAD TYP .220 – .310 (5.588 – 7.874) 1 2 .300 BSC (7.62 BSC) 3 4 .200 (5.080) MAX .015 – .060 (0.381 – 1.524) .008 – .018 (0.203 – 0.457) 0° – 15° NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE OR TIN PLATE LEADS .045 – .065 (1.143 – 1.651) .014 – .026 (0.360 – 0.660) .100 (2.54) BSC .125 3.175 MIN J8 0801 OBSOLETE PACKAGES 1077fa 14 LT1077 U PACKAGE DESCRIPTIO N8 Package 8-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) .400* (10.160) MAX 8 7 6 5 1 2 3 4 .255 ± .015* (6.477 ± 0.381) .300 – .325 (7.620 – 8.255) .009 – .015 (0.229 – 0.381) +.035 .325 –.015 ( 8.255 +0.889 –0.381 ) .045 – .065 (1.143 – 1.651) .130 ± .005 (3.302 ± 0.127) .065 (1.651) TYP .100 (2.54) BSC .125 (3.175) .020 MIN (0.508) MIN .018 ± .003 (0.457 ± 0.076) N8 0502 NOTE: 1. DIMENSIONS ARE INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm) 1077fa 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 LT1077 U PACKAGE DESCRIPTIO S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch) (Reference LTC DWG # 05-08-1610) .189 – .197 (4.801 – 5.004) NOTE 3 .045 ±.005 .050 BSC 8 7 6 5 N N .245 MIN .160 ±.005 1 .030 ±.005 TYP .150 – .157 (3.810 – 3.988) NOTE 3 .228 – .244 (5.791 – 6.197) 2 3 N/2 N/2 RECOMMENDED SOLDER PAD LAYOUT .010 – .020 × 45° (0.254 – 0.508) .008 – .010 (0.203 – 0.254) 1 .053 – .069 (1.346 – 1.752) 0°– 8° TYP .016 – .050 (0.406 – 1.270) NOTE: 1. DIMENSIONS IN .014 – .019 (0.355 – 0.483) TYP INCHES (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) 2 3 4 .004 – .010 (0.101 – 0.254) .050 (1.270) BSC SO8 0502 1077fa 16 Linear Technology Corporation LW/TP 1002 1K REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 1989