Transcript
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
