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LT1077 Micropower, Single Supply, Precision Op Amp
FEATURES

DESCRIPTIO
60A Max Supply Current 40V Max Offset Voltage 350pA Max Offset Current 0.5VP-P 0.1Hz to 10Hz Voltage Noise 2.5pAP-P 0.1Hz to 10Hz Current Noise O.4V/C Offset Voltage Drift 250kHz Gain-Bandwidth Product 0.12V/s 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
The LT(R)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.
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.
TYPICAL APPLICATIO
3.6V TO 9V 2
Distribution of Input Offset Voltage
35 30
PERCENT OF UNITS
Self Buffered Micropower Reference
7 LT1077 3 6 OUTPUT 1.230V 1.2% MAX SUPPLY CURRENT = 60A MAX SOURCES UP TO 10mA LOAD REGULATION = 30V/mA TEMPERATURE DRIFT = 12ppm/C
LT1077 * TA01
25 20 15 10 5
- +
4 LT1034 1.2V
0.1F
750k
0 0 -40 -30 -20 -10 10 20 30 40 INPUT OFFSET VOLTAGE (V) LT1077 * TA02
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VS = 5V, 0V TA = 25C 1072 UNITS TESTED IN H, J8, N8 PACKAGES
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LT1077
ABSOLUTE
AXI U
RATI GS (Note 1)
Operating Temperature Range LT1077AM/LT1077M (OBSOLETE).... - 55C to 125C LT1077AI/LT1077I.............................. - 40C to 85C LT1077AC/LT1077C/LT1077S8 ............... 0C to 70C Storage Temperature Range ................. - 65C to 150C Lead Temperature (Soldering, 10 sec).................. 300C
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
PACKAGE/ORDER I FOR ATIO
TOP VIEW VOS TRIM 8 VOS TRIM 1 A -IN 2 +IN 3 - ++ B - 6 OUT 5 NC 7 V+ VOS TRIM 1 -IN 2 +IN 3 V
-
TOP VIEW 8 7 6 5 VOS TRIM V+ OUT NC VOS TRIM 1 -IN 2 +IN 3 V- 4
4 V- H PACKAGE 8-LEAD TO-5 METAL CAN TJMAX = 150C, JA = 150C/W, JC = 45C/W
4
J8 PACKAGE 8-LEAD CERDIP TJMAX = 150C, JA = 100C/W
ORDER PART NUMBER LT1077AMH LT1077MH LT1077ACH LT1077CH
ORDER PART NUMBER LT1077AMJ8 LT1077MJ8 LT1077ACJ8 LT1077CJ8
OBSOLETE PACKAGE
Consider the N8 or S8 Package for Alternate Source
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
SYMBOL VOS VOS Time IOS IB en PARAMETER Input Offset Voltage LT1077S8 Long Term Input Offset Voltage Stability Input Offset Current Input Bias Current Input Noise Voltage Input Noise Voltage Density in Input Noise Current CONDITIONS
VS = 5V, 0V, VCM = 0.1V, VO = 1.4V, TA = 25C unless noted.
LT1077AM/AI/AC MIN TYP MAX 9 0.4 0.06 7 0.35 9 1.1 43 35 4.5 40 MIN LT1077M/I/C/S8 TYP MAX 10 12 0.4 0.06 7 0.5 28 27 2.5 0.45 11 60 150 UNITS V V V/Mo nA nA VP-P nV/Hz nV/Hz pAP-P
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0.1Hz to 10Hz (Note3) fO = 10Hz (Note 3) fO = 1000Hz (Note3) 0.1Hz to 10Hz (Note3)
2
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TOP VIEW 8 7 6 5 VOS TRIM V+ OUT NC
N8 PACKAGE 8-LEAD PDIP TJMAX = 100C, JA = 130C/W
S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150C, JA = 190C/W
ORDER PART NUMBER LT1077S8 LT1077IS8 LT1077AIN8 LT1077IN8 LT1077ACN8 LT1077CN8
S8 PART MARKING 1077 1077I
LT1077 * POI01
0.5 28 27 2.5
LT1077
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER Input Noise Current Density Input Resistance Differential Mode Common Mode Input Voltage Range CMRR PSRR AVOL Common Mode Rejection Ratio Power Supply Rejection Ratio Large-Signal Voltage Gain Maximum Output Voltage Swing VCM = 0V to 3.5V VS = 2.3V to 12V CONDITIONS
VS = 5V, 0V, VCM = 0.1V, VO = 1.4V, TA = 25C unless noted.
LT1077AM/AI/AC MIN TYP MAX 0.065 0.02 350 3.5 0 97 102 300 250 700 6 3.8 - 0.3 106 118 1000 1000 3.5 0.7 90 4.4 3.9 0.08 230 48 60 500 2.3 6 1.1 130 4.2 3.5 0.05 0.11 MIN LT1077M/I/C/S8 TYP MAX 0.065 0.02 270 3.5 0 94 100 240 200 700 6 3.8 - 0.3 105 117 1000 1000 3.5 0.7 90 4.4 3.9 0.08 230 48 900 2.2 2.3 68 6 1.1 130 UNITS pA/Hz pA/Hz M G V V dB dB V/mV V/mV mV mV mV V V V/s kHz A V V
fO = 10Hz (Note 3) fO = 1000Hz (Note 4)
VO = 0.03V to 4V, No Load VO = 0.03V to 3.5V, RL = 50k Output Low, No Load Output Low, 2k to GND Output Low, lSINK = 100A Output High, No Load Output High, 2k to GND (Note 2) fO 20kHz = 10k, Wiper to V+
4.2 3.5 0.05
SR GBW IS
Slew Rate Gain Bandwidth Product Supply Current Offset Adjustment Range Minimum Supply Voltage
Rpot
500
900 2.2
(Note 5)
The denotes the specifications which apply over the temperature range of -55C TA 125C for AM/M grades, -40C TA 85C for AI/I grades. VS = 5V, 0V, VCM = 0.1V, VO = 1.4V unless otherwise noted.
SYMBOL VOS VOS/T IOS IB CMRR PSRR AVOL PARAMETER Input Offset Voltage Input Offset Voltage Drift Input Offset Current Input Bias Current Common Mode Rejection Ratio Power Supply Rejection Ratio Large-Signal Voltage Gain Maximum Output Voltage Swing VCM = 0.05V to 3.2V VS = 3.1V to 12V VO = 0.05V to 3.5V, RL = 50k Output Low, No Load Output Low, ISINK = 100A Output High, No Load Output High, 2k to GND LT1077IS8 (Note 6) CONDITIONS

MIN
LT1077AM/AI TYP MAX 50 200
MIN
LT1077M/I TYP MAX 60 1 260 2.5 0.80 13
UNITS V V/C nA nA dB dB V/mV
0.08 8 92 98 120 104 114 600 4.5 120 4.2 3.7 54
0.60 11 88 94 100 8 170 3.9 3 80
0.08 8 103 113 600 4.5 120 4.2 3.7 54
8 170
3.9 3
mV mV V V A
IS
Supply Current
90
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LT1077
The denotes the specifications which apply over the temperature range of 0C TA 70C otherwise, specifications are at TA = 25C. VS = 5V, 0V, VCM = 0.1V, VO = 1.4V unless noted.
SYMBOL VOS VOS/T IOS IB CMRR PSRR AVOL PARAMETER Input Offset Voltage LT1077S8 Input Offset Voltage Drift Input Offset Current Input Bias Current Common Mode Rejection Ratio Power Supply Rejection Ratio Large-Signal Voltage Gain Maximum Output Voltage Swing VCM = 0V to 3.4V VS = 2.6V to 12V VO = 0.05V to 3.5V, RL = 50k Output Low, No Load Output Low, ISINK = 100A Output High, No Load Output High, 2k to GND (Note 6) LT1077S8 (Note 6) CONDITIONS

ELECTRICAL CHARACTERISTICS
MIN
LT1077AC TYP MAX 30 0.4 0.07 7 110 1.6 0.45 10
MIN
LT1077C/S8 TYP MAX 35 40 0.5 0.7 0.07 7 150 280 2.0 3.0 0.60 12
UNITS V V V/C V/C nA nA dB dB V/mV

94 100 180
105 116 800 4.0 100 4.3 3.8 52 7 150
90 97 150
104 115 800 4.0 100 4.3 3.8 52 7 150
4.1 3.3
4.1 3.3 70
mV mV V V A
IS
Supply Current
80
VS = 15V, TA = 25C unless noted.
SYMBOL VOS IOS IB PARAMETER Input Offset Voltage LT1077S8 Input Offset Current Input Bias Current Input Voltage Range CMRR PSRR AVOL VOUT SR IS Common Mode Rejection Ratio Power Supply Rejection Ratio Large-Signal Voltage Gain Maximum Output Voltage Swing Slew Rate Supply Current VCM = 13.5V to -15V VS = 5V, 0V to 18V VO = 10V, RL = 50k VO = 10V, RL = 2k RL = 50k RL = 2k 13.5 - 15.0 100 106 1000 400 13.0 11.0 0.07 0.06 7 13.8 - 15.3 109 122 8000 1500 14.0 13.2 0.12 56 75 0.35 9 13.5 - 15.0 97 103 800 300 13.0 11.0 0.07 CONDITIONS LT1077AM/AI/AC MIN TYP MAX 20 150 MIN LT1077M/I/C/S8 TYP MAX 25 30 0.06 7 13.8 - 15.3 108 120 8000 1500 14.0 13.2 0.12 56 85 200 300 0.45 11 UNITS V V nA nA V V dB dB V/mV V/mV V V V/s A
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LT1077
The denotes the specifications which apply over the temperature range of -55C TA 125C for AM/M grades, - 40C TA 85C for AI/I grades. VS = 15V unless otherwise noted.
SYMBOL VOS VOS/T IOS IB AVOL CMRR PSRR PARAMETER Input Offset Voltage Input Offset Voltage Drift Input Offset Current Input Bias Current Large-Signal Voltage Gain Common Mode Rejection Ratio Power Supply Rejection Ratio Maximum Output Voltage Swing IS Supply Current VO = 10V, RL = 5k VCM = 13V, -14.9V VS = 5V, 0V to 18V RL = 5k LT1077IS8 (Note 6) CONDITIONS

ELECTRICAL CHARACTERISTICS
MIN
LT1077AM/AI TYP MAX 60 330
MIN
LT1077M/I TYP MAX 75 1.1 450 3 0.80 13
UNITS V V/C nA nA V/mV dB dB V
0.08 8 300 94 100 11 1000 107 118 13.5 60
0.60 11 250 90 97 11 95
0.08 8 1000 106 116 13.5 60
105
A
The denotes the specifications which apply over the temperature range of 0C TA 70C. VS = 15V unless otherwise noted.
SYMBOL VOS VOS/T IOS IB AVOL CMRR PSRR PARAMETER Input Offset Voltage LT1077S8 Input Offset Voltage Drift Input Offset Current Input Bias Current Large-Signal Voltage Gain Common Mode Rejection Ratio Power Supply Rejection Ratio Maximum Output Voltage Swing IS Supply Current VO = 10V, RL = 5k VCM = 13V, -15V VS = 5V, 0V to 18V RL = 5k (Note 6) LT1077S8 (Note 6) CONDITIONS

MIN
LT1077AC TYP MAX 40 0.4 0.07 7 230 1.8 0.45 10
MIN
LT1077C/S8 TYP MAX 50 65 0.5 0.8 0.07 7 320 450 2.5 3.5 0.60 12
UNITS V V V/C V/C nA nA V/mV dB dB V
500 97 103 11
2000 108 120 13.6 59 85
400 94 100 11
2000 107 118 13.6 59 95
A
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.
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 - 300V. Note 6: This parameter is not 100% tested.
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LT1077 TYPICAL PERFOR A CE CHARACTERISTICS
Supply Current vs Temperature
OFFSET CURRENT (pA)
60
SUPPLY CURRENT (A)
VS = 15V VS = 5V, 0V 50
50
INPUT BIAS CURRENT (nA)
BIAS CURRENT (nA)
40
-50 -25
50 25 75 0 TEMPERATURE (C)
0.1Hz to 10Hz Noise
VS = 2.5V TA = 2.5C NOISE VOLTAGE (0.4V/DIV) NOISE VOLTAGE (0.4V/DIV)
VOLTAGE NOISE DENSITY (nV/Hz) CURRNET NOISE DENSITY (fA/Hz)
0.4V
0
2
6 4 TIME (SECONDS)
10Hz Voltage Noise Distribution
35 30 VS = 2.5V TA = 2.5C
PERCENT OF UNITS 30
PERCENT OF UNITS
20 15 10 5 0 25 35 30 VOLTAGE NOISE DENSITY (nV/Hz) 40
20
PERCENT OF UNITS
25
6
UW
100 8
Input Bias and Offset Currents vs Temperature
-1
Input Bias Currents vs Common Mode Voltage
VS = 5V, 0V
100 75
VS = 5V, 0V TO 15V IOS
-3 -5 -7
TA = 25C
TA = 55C
-6 IB -7
TA = 125C -9 -11 -13 -1
125
-8 -50 -25
50 25 0 75 TEMPERATURE (C)
100
125
0 1 2 3 COMMON MODE VOLTAGE (V)
4
LT1077 * TPC03
LT1077 * TPC01
LT1077 * TPC02
0.01Hz to 10Hz Noise
VS = 2.5V TA = 2.5C 1000
Noise Spectrum
VS = 2.5V TA = 25C (AT VS = 15V VOLTAGE NOISE IS 4% LESS CURRENT NOISE IS UNCHANGED
300
CURRENT NOISE
100 VOLTAGE NOISE 30 1/f CORNER 0.7Hz 10 0.1 1 10 100 FREQUENCY (Hz) 1000
LT1077 * TPC06
10
0
20
60 40 TIME (SECONDS)
80
100
LT1077 * TPC04
LT1077 * TPC05
Distribution of Offset Voltage Drift with Temperature (In All Packages)
VS = 5V, 0V VCM = 0.1V
Distribution of Input Offset Voltage in Small Outline (S8) Package
70 60 50 40 30 20 10 VS = 5V, 0V TA = 25C 456 UNITS TESTED
400 UNITS TESTED (100 IN EACH PACKAGE)
10
0 -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 (V)
LT1077 * TPC09
LT1077 * TPC07
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LT1077 TYPICAL PERFOR A CE CHARACTERISTICS
Voltage Gain vs Frequency
140 TA = 25C 120
30
VOLTAGE GAIN (dB)
80 60 40 20 0 -20 0.01 0.1 1 10 100 1k 10k 100k 1M FREQUENCY (Hz)
LT1077 * TPC10
10
GAIN
PHASE MARGIN 54 15V 5V, 0V
15V 140 160 180 200
OVERSHOOT (%)
VS = 15V
VOLTAGE GAIN (dB)
100
20 5V, 0V
120
PHASE SHIFT (DEGREES)
VS = 5V, 0V
Slew Rate, Gain Bandwidth Product and Phase Margin vs Temperature
SLEW RATE (V/s)
0.14 0.12 0.10 0.08 0.06 fO = 20kHz
SLEW 15V SLEW 5V, 0V 80 M 15V M 5V, 0V 70 60 50 GBW 15V 40
PHASE MARGIN (DEGREES)
1V/DIV
0V
5V/DIV
GAIN BANDWIDTH PRODUCT (kHz)
260 240 220 200 180 -50 -25 GBW 5V, 0V 25 50 0 75 TEMPERATURE (C) 100
Small-Signal Transient Response VS = 5V, 0V
20mV/DIV
20mV/DIV
20mV/DIV
AV = 1 10s/DIV CL = 15pF INPUT 50mV TO 150mV
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LT1077 * TPC13
Gain, Phase vs Frequency
PHASE MARGIN 66 PHASE
Capacitive Load Handling
120
100
100 80
VS = 5V, 0V TA = 25C
AV = 1 60 40 20 0 10 100 1000 CAPACITIVE LOAD (pF) 10,000
LT1077 * TPC12
0 TA = 25C CL = 20pF -10 10k 30k 100k 300k FREQUENCY (Hz)
AV = 5
AV = 10
1M
LT1077 * TPC11
Large-Signal Transient Response VS = 5V, 0V
Large-Signal Transient Response VS = 15V
0V
100s/DIV 50s/DIV AV = 1 NO LOAD INPUT PULSE 0V TO 3.8V AV = 1 NO LOAD
125
Small-Signal Transient Response VS = 2.5V
Small-Signal Transient Response VS = 15V
0.1V
0V
0V
AV = 1 CL = 15pF
10s/DIV
AV = 1 CL = 15pF
10s/DIV
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LT1077 TYPICAL PERFOR A CE CHARACTERISTICS
Minimum Supply Voltage
100 0 125C -100 -200 -300 -400 -500 0 2 3 1 POSITIVE SUPPLY VOLTAGE (V)
LT1077 * TPC19
CHANGE IN OFFSET VOLTAGE (V)
V - = 0V - 0.1 VCM 0.4V
70C
INPUT OFFSET VOLTAGE (V)
VOLTAGE GAIN (V/V)
NON FUNCTIONAL
0C 25C
Output Saturation vs Temperature vs Sink Current
1000
VS = 5V, 0V
ISINK = 2mA OUTPUT VOLTAGE SWING (V) ISINK = 1mA
SHORT-CIRCUIT CURRENT (mA) SINKING SOURCING
SATURATION VOLTAGE (mV)
100
ISINK = 100A ISINK = 10A
10
ISINK = 1A NO LOAD RL = 5k TO GROUND
0 -50 -25
0
25
50
75
TEMPERATURE (C)
LT1077 * TPC22
Common Mode Range vs Temperature
V + = 2.5V TO 18V V - = 0V TO -18V
PEAK-TO-PEAK OUTPUT SWING, VS = 15V (V)
V+ V+ - 1
COMMON MODE RANGE (V)
OUTPUT IMPEDANCE ()
V+ - 2
V- + 1
V- V- - 1 - 50 -25
50 25 0 75 TEMPERATURE (C)
8
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-55C
100
Warm-Up Drift
0.8 VS = 15V TA = 25C
Voltage Gain vs Load Resistance
10M 1. 25C 2. -55C VS = 15V 3. 125C 1 2 3 4 5 6
WARM UP DRIFT 0.6 AT VS = 5V, 0V IS IMMEASURABLY LOW
0.4
1M
0.2
0
0
1
2
3
LT1077 * TPC20
100k 100
4. -55C 5. 25C VS = 5V, 0V 6. 125C 10k 1k 100k LOAD RESISTANCE TO GROUND () 1M
TIME AFTER POWER ON (MINUTES)
LT1077 * TPC21
Output Voltage Swing vs Load Current
V+ 125C V+ - 1 V+ - 2 -55C 25C
Short-Circuit Current vs Time
40 30 20 10 TA = 125C, VS = 5V, 0V 0 -10 TA = 125C, VS = 15V -20 -30
-55C
TA = 25C, VS = 5V, 0V TA = 25C, VS = 15V
TA = 125C, VS = 15V
V- + 2 V- + 1 V- 0.01 25C
125C
TA = 25C, VS = 15V
-40
10
125
0.1
1
SOURCING OR SINKING LOAD CURRENT (mA)
LT1077 * TPC23
1 2 3 0 TIME FROM OUTPUT SHORT TO GROUND (MINUTES)
LT1077 * TPC24
Undistorted Output Swing vs Frequency
30
Closed Loop Output Impedance
PEAK-TO-PEAK OUTPUT SIWNG, VS = 5V, 0V (V)
1k
TA = 25C LOAD RL, TO GROUND VS = 5V, 0V, RL 100k
5 4 3 2
20 VS = 5V, 0V RL 1k 10 VS = 15V RL = 30k 0 100 1k 10k FREQUENCY (Hz)
100
AV = 100
VS = 15V RL 100k
10
AV = 1 AV = 10
1
1 0 100k
LT1077 * TPC26
0.1 10 10k 100 1k FREQUENCY (Hz) 100k
LT1077 * TPC27
100
125
LT1077 * TPC25
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LT1077 TYPICAL PERFOR A CE CHARACTERISTICS
Common Mode Rejection Ratio vs Frequency
120 120
COMMON MODE REJECTION RATIO (dB)
POWER SUPPLY REJECTION RATIO (dB)
100 VS = 15V 80 60 40 20 0 10 100 1k 10k FREQUENCY (Hz) 100k 1M VS = 5V, 0V
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 ( = 2V/V), at 9V the offset voltage change will be 8V. Similarly, VS 2.5V, VCM = 0 is equivalent to a common mode voltage change of 2.4V or a V OS change of 7V if CMRR = 110dB (3V/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+.
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Power Supply Rejection Ratio vs Frequency
TA = 25C
100 80 60 NEGATIVE SUPPLY 40 20
POSITIVE SUPPLY
0 0.1
VS = 2.5V + 1VP-P SINE WAVE TA = 25C 1 10 100 1k 10k FREQUENCY (Hz) 100k
LT1077 * TPC29
LT1077 * TPC28
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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
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LT1077
APPLICATIO S I FOR ATIO
resistors.) When the output is high the pull-down resistor draws 80A 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 2A. 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
5V R 99R 100mV 1mV
Voltage Follower
5V
- +
-
1mV
+
Voltage Follower with Input Exceeding the Negative Common Mode Range (VS = 5V, 0V)
4V 2V 0
4V 2V 0
6VP-P INPUT -1.0 TO 5.0V
1ms/DIV
OP-90 1ms/DIV EXHIBITS OUTPUT PHASE REVERSAL
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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): 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. b) When the input is more than 400mV below ground (at 25C), 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
LT1077 * AI01
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4V 2V 0
LT1077 1ms/DIV NO PHASE REVERSAL
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LT1077
APPLICATIO S I FOR ATIO
Comparator Applications
The single supply operation of the LT1077 and its ability to swing close to ground while sinking current,
Comparator Rise Response Time to 10mV, 5mV, 2mV Overdrive
OUTPUT (V)
4 2 0 0 -100 VS = 5V, 0V 200s/DIV
OUTPUT (V) INPUT (mV)
INPUT (mV)
TYPICAL APPLICATIO S
Megaohm Input Impedance Gain of 10 Difference Amplifier
10M
-
INPUT
1M
+
1M
10M
BANDWIDTH = 20KHZ OUTPUT OFFSET = 0.7mV OUTPUT NOISE = 80VPP (0.1Hz TO 10Hz) 260VRMS OVER FULL BANDWIDTH SUPPLY CURRENT = 45A 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
U
lends itself to use as a precision comparator with TTL compatible output.
Comparator Fall Response Time to 10mV, 5mV, 2mV Overdrive
4 2 0 100 0 VS = 5V, 0V 200s/DIV
W
U
UU
2
3V 7 6 OUTPUT 0.005 TO 2.4V
3 4
1077fa
11
LT1077
TYPICAL APPLICATIO S
250V Common Mode Range Difference Amplifier (AV = 1)
R1 1M - IN 3 R2 20k 2 R3 1M + IN 7 6 4 3V TO 18V 7 6 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) = 500V OUTPUT OFFSET DRIFT = 25V/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 R6 25k 2 OUT R5 975k 1 50k OPTIONAL CMRR TRIM
COMMON MODE INPUT 250V
Two Terminal Current Source
3.6V TO 40V 2
- +
7 LT1077 6
3
4 IS + VR1 -
750k
R1 LT1034 1.2V
LT1077 * TA05
IO VR1 + IS R1 1.230V + 50A R1
RL
IO = =
MINIMUM CURRENT = 50A (R1 ) MAXIMUM CURRENT = 10.3mA (R1 = 120)
12
U
Half-Wave Rectifier
2M
1M INPUT 1M
3V
-
LT1077 OUTPUT V0MIN = 6mV NO DISTORTION TO 100Hz 1.8V -1.8V 0
LT1077 * TA06
+
1.8V
1077fa
V+
700 2.2k 5.6k 1.3k 3.6k 5k 11.5k 12.5k Q53 2 Q52 Q54 1 1 Q16 Q14 Q15 Q32 Q47 Q37 Q3 Q24 Q30 C1 50pF 1 3 Q25 Q35 V+ Q26 2.9k 30 Q44 C4 4pF C5 2.5pF Q27 OUT Q31 J1 Q36 Q33 Q50 Q39 Q23 V+ Q20 10k Q34 1.35k 6.2k 6.2k 30 Q38 5.35k Q45 Q51 Q55 Q43 9.1k Q42 Q48 Q49 Q28 Q18 V+ Q19 C3 40pF 150k 3k Q40 Q41 8.6k Q12 4 1 Q4 Q29 V- Q46
700
NULL
NULL
SI PLIFIED SCHE ATIC W
LT1077
Q5
Q6
Q1
600
Q1
-IN
Q21
600
Q2
+IN
Q22
Q9 Q10 Q17 Q7 Q8
700k
C2 175pF
700k
V-
LT1077 * S01
W
9k
9k
13
1077fa
LT1077
PACKAGE DESCRIPTIO
.335 - .370 (8.509 - 9.398) DIA .305 - .335 (7.747 - 8.509) .040 (1.016) MAX .050 (1.270) MAX GAUGE PLANE .165 - .185 (4.191 - 4.699)
SEATING PLANE .010 - .045* (0.254 - 1.143) .016 - .021** (0.406 - 0.533)
CORNER LEADS OPTION (4 PLCS)
.045 - .068 (1.143 - 1.650) FULL LEAD OPTION .300 BSC (7.62 BSC)
.008 - .018 (0.203 - 0.457)
NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE OR TIN PLATE LEADS
14
U
H Package 8-Lead TO-5 Metal Can (.200 Inch PCD)
(Reference LTC DWG # 05-08-1320)
45TYP .028 - .034 (0.711 - 0.864) .200 (5.080) TYP .027 - .045 (0.686 - 1.143) PIN 1 REFERENCE PLANE .500 - .750 (12.700 - 19.050) .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)
.405 (10.287) MAX 8 7 6 5
.005 (0.127) MIN
.023 - .045 (0.584 - 1.143) HALF LEAD OPTION
.025 (0.635) RAD TYP 1 2 3
.220 - .310 (5.588 - 7.874)
4
.200 (5.080) MAX .015 - .060 (0.381 - 1.524)
0 - 15
.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
LT1077
PACKAGE DESCRIPTIO
.300 - .325 (7.620 - 8.255)
.009 - .015 (0.229 - 0.381) +.035 .325 -.015
(
8.255
+0.889 -0.381
)
INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)
NOTE: 1. DIMENSIONS ARE
Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
U
N8 Package 8-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510)
.400* (10.160) MAX 8 7 6 5 .255 .015* (6.477 0.381) 1 2 3 4 .130 .005 (3.302 0.127) .045 - .065 (1.143 - 1.651) .065 (1.651) TYP .125 (3.175) .020 MIN (0.508) MIN .018 .003 (0.457 0.076)
N8 0502
.100 (2.54) BSC
1077fa
15
LT1077
PACKAGE DESCRIPTIO
.050 BSC
8 N N .245 MIN .160 .005 .228 - .244 (5.791 - 6.197) 1 2 3 N/2
.030 .005 TYP
RECOMMENDED SOLDER PAD LAYOUT
.010 - .020 x 45 (0.254 - 0.508) .008 - .010 (0.203 - 0.254) 0- 8 TYP
.016 - .050 (0.406 - 1.270) NOTE: 1. DIMENSIONS IN
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)
16
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 FAX: (408) 434-0507
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S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
.045 .005
.189 - .197 (4.801 - 5.004) NOTE 3 7 6 5 .150 - .157 (3.810 - 3.988) NOTE 3 N/2 1 2 3 4 .053 - .069 (1.346 - 1.752) .004 - .010 (0.101 - 0.254) .014 - .019 (0.355 - 0.483) TYP .050 (1.270) BSC
SO8 0502
1077fa LW/TP 1002 1K REV A * PRINTED IN USA
www.linear.com
LINEAR TECHNOLOGY CORPORATION 1989

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