LT1097
Low Cost, Low Power
Precision Op Amp
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DESCRIPTION
FEATURES
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■
■
■
■
■
■
Offset Voltage
50µV Max
Offset Voltage Drift
1µV/°C Max
Bias Current
250pA Max
Offset Current
250pA Max
Bias and Offset Current Drift
4pA/°C Max
Supply Current
560µA Max
0.1Hz to 10Hz Noise
0.5µVp-p, 2.2pAp-p
CMRR
115dB Min
Voltage Gain
117dB Min
PSRR
114dB Min
Guaranteed Operation on Two NiCad Batteries
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APPLICATIONS
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Replaces OP-07/OP-77/OP-97/OP-177/AD707/
LT1001 with Improved Price/Performance
High Impedance Difference Amplifiers
Logarithmic Amplifiers (Wide Dynamic Range)
Thermocouple Amplifiers
Precision Instrumentation
Active Filters (with Small Capacitors)
LT®1097 achieves a new standard in combining low price
and outstanding precision performance.
On all operational amplifier data sheets, the specifications
listed on the front page are for highly selected, expensive
grades, while the specs for the low cost grades are buried
deep in the data sheet.
The LT1097 does not have any selected grades, the
outstanding specifications shown in the Features section
are for its only grade.
The design effort of the LT1097 concentrated on optimizing the performance of all precision specs—at only 350µA
of supply current. Typical values are 10µV offset voltage,
40pA bias and offset currents, 0.2µV/°C and 0.4pA/°C
drift. Common mode and power supply rejections, voltage
gain are typically in excess of 128dB.
All parameters that are important for precision, low power
op amps have been optimized. Consequently, using the
LT1097 error budget calculations in most applications is
unnecessary.
, LTC and LT are registered trademarks of Linear Technology Corporation.
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TYPICAL APPLICATION
Input Offset Voltage Distribution
Saturated Standard Cell Amplifier
9V
50
2N3609
+
7
LT1097
2
+
1.018235V
SATURATED
STANDARD
CELL #101
EPPLEY LABS
NEWPORT, R. I.
R1
20k
–
40
6
OUT = 1.1V TO 8.0V
AS 1.8k ≤ R2 ≤ 135k
4
PERCENT OF UNITS
3
30
6,500 UNITS IN SO PACKAGE
6,680 UNITS IN
PLASTIC
VS = ±15V
DIP
TA = 25°C
13,180 UNITS
TESTED
20
10
R2
THE TYPICAL 40pA BIAS CURRENT OF THE LT1097
WILL DEGRADE THE STANDARD CELL BY ONLY
1ppm/YEAR. NOISE IS A FRACTION OF A ppm.
UNPROTECTED GATE MOSFET ISOLATES
STANDARD CELL ON POWER DOWN.
0
–50 –40 –30 –20 –10 0 10 20 30 40 50
INPUT OFFSET VOLTAGE (µV)
LT1097 • G01
LT1097•TA01
1
LT1097
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ABSOLUTE MAXIMUM RATINGS
Supply Voltage ...................................................... ±20V
Differential Input Current (Note 1) ...................... ±10mA
Input Voltage ......................................................... ±20V
Output Short Circuit Duration .......................... Indefinite
Operating Temperature Range .................–40°C to 85°C
Storage Temperature Range ..................–65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
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PACKAGE/ORDER INFORMATION
TOP VIEW
VOS TRIM 1
8
VOS TRIM
–IN 2
7
V+
+IN 3
6
OUT
V– 4
5
OVER COMP
ORDER
PART NUMBER
LT1097CN8
TOP VIEW
VOS TRIM 1
8
VOS TRIM
–IN 2
7
V+
+IN 3
6
OUT
V– 4
5
OVER COMP
N8 PACKAGE
8-LEAD PLASTIC DIP
LT1097S8
S8 PACKAGE
8-LEAD PLASTIC SO
ELECTRICAL CHARACTERISTICS
VS = ±15V, VCM = 0V, TA = 25°C, unless otherwise noted.
CONDITIONS
MIN
LT1097CN8
TYP
MAX
SYMBOL
PARAMETER
VOS
Input Offset Voltage
10
Long Term Input Offset
Voltage Stability
0.3
∆VOS
∆TIME
ORDER
PART NUMBER
MIN
50
LT1097S8
TYP
MAX
10
60
UNITS
µV
µV/Mo
0.3
IOS
Input Offset Current
40
250
60
350
pA
IB
Input Bias Current
±40
±250
±50
±350
pA
en
Input Noise Voltage
0.1Hz to 10Hz
0.5
0.5
µVp-p
Input Noise Voltage Density
fO = 10Hz
fO = 1000Hz
16
14
16
14
nV/√Hz
nV/√Hz
Input Noise Current
0.1Hz to 10Hz
2.2
2.4
pAp-p
Input Noise Current Density
fO = 10Hz
fO = 1000Hz
0.03
0.008
0.035
0.008
pA/√Hz
pA/√Hz
Input Resistance
Differential Mode
Common Mode
(Note 2)
in
Input Voltage Range
CMRR
Common Mode Rejection Ratio
VCM = ±13.5V
30
80
1012
25
70
8•1011
MΩ
Ω
±13.5
±14.3
±13.5
±14.3
V
115
130
115
130
dB
PSRR
Power Supply Rejection Ratio
VS = ±1.2V to ±20V
114
130
114
130
dB
AVOL
Large Signal Voltage Gain
VO = ±12V, RL = 10k
VO = ±10V, RL = 2k
700
250
2500
1000
700
250
2500
1000
V/mV
V/mV
VOUT
Output Voltage Swing
RL = 10k
RL = 2k
±13
±11.5
±13.8
±13
±13
±11.5
±13.8
±13
V
V
SR
Slew Rate
0.1
0.2
0.1
0.2
V/µs
GBW
Gain Bandwidth Product
700
kHz
IS
Supply Current
2
700
350
Offset Adjustment Range
RPOT = 10k, Wiper to V+
Minimum Supply Voltage
(Note 3)
560
350
±600
±1.2
—
±1.2
560
µA
±600
µV
—
V
LT1097
ELECTRICAL CHARACTERISTICS
VS = ±15V, VCM = 0V, 0°C ≤ TA ≤ 70°C, unless otherwise noted.
LT1097S8
TYP
MAX
UNITS
100
20
130
µV
0.2
1
0.2
1.4
µV/°C
●
60
430
75
570
pA
Average Temperature Coefficient of (Note 4)
Input Offset Current
●
0.4
4
0.5
5
Input Bias Current
●
±60
±430
±75
±570
Average Temperature Coefficient of (Note 4)
Input Bias Current
●
0.4
4
0.5
5
PARAMETER
VOS
Input Offset Voltage
●
20
Average Temperature Coefficient of (Note 4)
Input Offset Voltage
●
Input Offset Current
IOS
IB
CONDITIONS
MIN
LT1097CN8
TYP
MAX
SYMBOL
MIN
pA/°C
pA
pA/°C
AVOL
Large Signal Voltage Gain
VOUT = ±12V, RL ≥ 10k
VOUT = ±10V, RL ≥ 2k
●
●
450
180
2000
800
450
180
2000
800
V/mV
V/mV
CMRR
Common Mode Rejection Ratio
VCM = ±13.5V
●
112
128
112
128
dB
PSRR
Power Supply Rejection Ratio
VS = ±1.3V to ±20V
●
111
128
111
128
dB
●
±13.5
±14.2
±13.5
±14.2
V
●
±13
±13.7
±13
±13.7
Input Voltage Range
VOUT
Output Voltage Swing
IS
Supply Current
RL = 10k
380
●
ELECTRICAL CHARACTERISTICS
V
700
µA
LT1097S8
TYP
MAX
UNITS
130
30
170
µV
0.3
1.2
0.3
1.6
µV/°C
●
70
600
85
750
pA
Average Temperature Coefficient of
Input Offset Current
●
0.5
5
0.6
6
Input Bias Current
●
±70
±600
±85
±750
Average Temperature Coefficient of
Input Bias Current
●
0.5
5
0.6
6
CONDITIONS
MIN
LT1097CN8
TYP
MAX
PARAMETER
VOS
Input Offset Voltage
●
25
Average Temperature Coefficient of
Input Offset Voltage
●
Input Offset Current
IB
380
VS = ±15V, VCM = 0V, –40°C ≤ TA ≤ 85°C, unless otherwise noted. (Note 5)
SYMBOL
IOS
700
MIN
pA/°C
pA
pA/°C
AVOL
Large Signal Voltage Gain
VOUT = ±12V, RL ≥ 10k
VOUT = ±10V, RL ≥ 2k
●
●
300
1700
700
300
1700
700
V/mV
V/mV
CMRR
Common Mode Rejection Ratio
VCM = ±13.5V
●
108
127
108
127
dB
PSRR
Power Supply Rejection Ratio
VS = ±1.5V to ±20V
●
108
127
108
127
dB
●
±13.5
±14
±13.5
±14
V
●
±13
±13.6
±13
±13.6
Input Voltage Range
VOUT
Output Voltage Swing
IS
Supply Current
RL = 10k
The ● denotes specifications which apply over the full operating
temperature range.
Note 1: Differential input voltages greater than 1V will cause excessive
current to flow through the input protection diodes unless limiting
resistance is used.
Note 2: This parameter is guaranteed by design and is not tested.
●
400
800
400
V
800
µA
Note 3: Power supply rejection ratio is measured at the minimum supply
voltage.
Note 4: This parameter is not 100% tested.
Note 5: The LT1097 is designed, characterized and expected to meet these
extended temperature limits, but is not tested at –40°C and 85°C.
Guaranteed I grade parts are available; consult factory.
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LT1097
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TYPICAL PERFORMANCE CHARACTERISTICS
Distribution to Offset Voltage Drift
with Temperature
50
VS = ±15V
240 UNITS TESTED
IN N8 PACKAGES
FROM SIX RUNS
PERCENT OF UNITS
40
30
20
10
0
–1.5 –1.2 –0.9 –0.6 –0.3 0 0.3 0.6 0.9 1.2 1.5
OFFSET VOLTAGE DRIFT WITH TEMPERATURE (µV/°C)
LT1097 • G02
Minimum Supply Voltage,
Common Mode Range and
Voltage Swing at VMIN
INPUT BIAS CURRENT (pA)
200
100
UNDERCANCELLED UNIT
0
–100
OVERCANCELLED UNIT
–200
–300
–50
–25
0
25
50
TEMPERATURE (°C)
75
V+
±1.4
V+ –0.2
±1.2
V+ –0.4
V+ –0.6
±1.0
CM RANGE
±0.8
V+ –0.8
SWING
V– +0.8
SWING
RL = 10k
V– +0.6
CM RANGE
V– +0.4
V– +0.2
100
V–
–40
–10
20
50
TEMPERATURE (°C)
80
1097 • G03
Input Bias Current Over Common
Mode Range
120
VS = ±15V
TA = 25°C
80
INPUT BIAS CURRENT (pA)
CHANGE IN OFFSET VOLTAGE (µV)
5
3
2
PLASTIC-IN-LINE PACKAGE
PLASTIC (N) OR SO (S)
1
0
1
2
3
4
TIME AFTER POWER ON (MINUTES)
5
1097 • G05
4
VS = ±15V
TA = 25°C
DEVICE WITH POSITIVE INPUT CURRENT
40
RIN CM = 1012Ω
0
DEVICE WITH NEGATIVE INPUT CURRENT
–40
–
–80
0
110
1097 • G04
Warm-Up Drift
4
MINIMUM SUPPLY VOLTAGE, VMIN (V)
COMMON MODE RANGE OR OUTPUT SWING (V)
Input Bias Current vs Temperature
–120
–15
VCM
IB
+
–10
–5
0
5
10
COMMON MODE INPUT VOLTAGE
15
1097 • G06
LT1097
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TYPICAL PERFORMANCE CHARACTERISTICS
Output Short Circuit Current vs Time
SHORT CIRCUIT CURRENT (mA)
SINKING
SOURCING
20
15
10
5
VS = ±15V
TA = 25°C
0
–5
–10
–15
–20
0
1
2
TIME FROM OUTPUT SHORT (MINUTES)
3
1097 • G07
0.1Hz to 10Hz Noise
0.01Hz to 10Hz Noise
0
2
4
6
TIME (SECONDS)
8
VS = ±1.2V TO ±20V
TA = 25°C
0.4µV
NOISE VOLTAGE (0.4µV/DIV)
NOISE VOLTAGE (0.4µV/DIV)
VS = ±1.2V TO ±20V
TA = 25°C
10
0
20
40
60
TIME (SECONDS)
80
1097 • G08
1097 • G09
Voltage Gain
Noise Spectrum
1000
–30
TA = 25°C
VS = ±1.2V TO ±20V
100
CURRENT NOISE
VOLTAGE NOISE
10
1/f CORNER
2.5Hz
1/f CORNER
140Hz
1
1
10
100
FREQUENCY (Hz)
1000
1097 • G10
CHANGE IN OFFSET VOLTAGE (µV)
VOLTAGE NOISE DENSITY (nV√Hz)
CURRENT NOISE DENSITY (fA√Hz)
100
–20
Vs = ±15 V
TA = 25°C
–10
RL = 10k
0
10
RL = 10k
RL = 2k
RL = 2k
20
30
–15
–10
–5
0
5
OUTPUT VOLTAGE (V)
10
15
1097 • G11
5
LT1097
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TYPICAL PERFORMANCE CHARACTERISTICS
Voltage Gain vs Frequency
140
VS = ±15V
TA = 25°C
120
VOLTAGE GAIN (dB)
100
80
60
40
20
0
–20
0.01 0.1
1
10 100 1k 10k 100k 1M 10M
FREQUENCY (Hz)
1097 • G12
Common Mode Rejection vs
Frequency
Gain, Phase Shift vs Frequency
PHASE
120
GAIN (dB)
GAIN
20
140
10
160
0
180
PHASE MARGIN = 70°C
0.1
1
FREQUENCY (MHz)
10
PHASE SHIFT (DEGREES)
30
–10
0.01
140
100
VS = ±15V
TA = 25°C
COMMON MODE REJCTION RATIO (dB)
40
VS = ±15V
TA = 25°C
120
100
80
60
40
20
0
200
1
10
100
1k
10k
FREQUENCY (Hz)
100k
1097 • G13
1097 • G14
Slew Rate, Gain Bandwidth
Product vs Overcompensation
Capacitor
Power Supply Rejection vs
Frequency
1
SLEW RATE (V/µs)
120
100
NEGATIVE SUPPLY
80
POSITIVE SUPPLY
60
SLEW
0.1
GBW
0.01
100
10
40
VS = ±15V
TA = 25°C
0.001
1
10
100 1k 10k 100k
FREQUENCY (Hz)
1M
1097 • G15
6
1000
VS = ±15V
TA = 25°C
1
1
10
100
1000
10000
OVERCOMPENSATION CAPACITOR (pF)
1097 • G16
GAIN BANDWIDTH PRODUCT (kHz)
POWER SUPPLY REJECTION RATIO (dB)
140
20
0.1
1M
LT1097
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TYPICAL PERFORMANCE CHARACTERISTICS
Large Signal Transient Response
2V/DIV
20mV/DIV
Small Signal Transient Response
AV = 1, CLOAD = 100pF, 5µs/DIV
1097 G17
AV = 1, 20µs/DIV
1097 G18
Capacitive Load Handling
70
TA = 25°C
VS = ±15V
CS: PIN 5 TO GROUND
60
OVERSHOOT (%)
50
AV = 1
CS = 0
40
30
AV = 1
CS = 200pF
20
10
AV = 10
CS = 0
0
10
100
1000
CAPACITIVE LOAD (pF)
10,000
1097 G19
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LT1097
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SCHEMATIC DIAGRAM
TRIM 1
TRIM 8
V+
5 OVER COMP
7
800Ω
800Ω
30k
30k
20µA
35µA
80µA
1.3k
30pF
Q19
Q22
1.5k
2.5k
1.5k
Q33
Q25
Q21
Q27
Q6
Q5
Q29
S
Q8
Q24
Q4
40Ω
Q7
– IN
S
S
Q1
2
Q2
100Ω
3k
Q13
S
OUT
6
Q11 Q23
1.5k
40Ω
Q3
Q20
50k
Q28
J1
1.5k
Q26
Q9
Q32
Q18
Q12
Q16
+IN
Q10
Q17
3
3.7k
15µA
80µA
Q30
5µA
Q31
Q14
Q15
5µA
3.7k
3.7k
16k
40Ω
330Ω
V– 4
Q1–Q4 ARE SUPERGAIN TRANSISTORS
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1097 BD
LT1097
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APPLICATIONS INFORMATION
The LT1097 is pin compatible to and directly replaces such
precision op amps as the OP-07, OP-77, AD707, OP-97, OP177, LM607 and LT1001 with improved price/performance.
Compatibility includes externally nulling the offset voltage, as
all of the above devices are trimmed with a potentiometer
between Pin 1 and Pin 8 and the wiper tied to V+.
The simple difference amplifier can be used to illustrate
the all-around excellence of the LT1097. The 50k input
resistance is selected to be large enough compared to
input signal source resistance. Simultaneously, the 50k
resistors should not dominate the precision and noise
error budget. Assuming perfect matching between the
four resistors, the following table summarizes the input
±27V Common Mode Range Difference Amplifier
referred performance obtained using the LT1097 and
other popular, low cost precision op amps.
Input offset voltage can be adjusted over a ±600µV range
with a 10k potentiometer.
The LT1097 is internally compensated for unity gain
stability. As shown on the Capacitive Load Handling plot,
the LT1097 is stable with any capacitive load. However,
the overcompensation capacitor, CS, can be used to reduce overshoot with heavy capacitive loads, to narrow
noise bandwidth or to stabilize circuits with gain in the
feedback loop.
Frequency Compensation and Optional Offset Nulling
50k
15V
50k
–IN
50k
+IN
2
–
3
50k
+
1
2
7
LT1097
V+
10k
POT
6
–
8
LT1097
OUT
3
4
+
4
–15V
7
6
OUT
5
CS
V–
LT1097•F02
LT1097•F01
Guaranteed Perfomance, VS = ±15V, TA = 25°C
PARAMETER
LT1097CN8
OP-77GP
AD707JN
OP-177GP
OP-97FP
Error Terms
VOS Max
IOS Max•25k
Gain Min, 10V Out
CMRR, Min, ±25V In
PSRR, Min, VS = ±15V ±10%
UNITS
50
6
14
22
6
100
70
5
20
9
90
50
3
13
9
60
70
5
22
9
75
4
50
39
9
µV
µV
µV
µV
µV
Sum of All Error Terms
98
204
165
166
177
µV
0.1Hz to 10Hz Noise
Voltage Noise
Current Noise•50k
Resistor Noise
0.5
0.11
0.55
0.38
0.75
0.55
0.23
0.7
0.55
0.38
0.75
0.55
0.5
0.1
0.55
µVp-p Typ
µVp-p Typ
µVp-p Typ
RMS sum
0.75
1
0.92
1
0.75
µVp-p
Drift with Temp
TCVOS Max
TCIOS Max•25k
1
0.1
1.2
2.1
1
1
1.2
2.1
2
0.2
µV/°C
µV/°C
Sum of Drift Terms
1.1
3.3
2
3.3
2.2
µV/°C
Supply Current Max
0.56
2
3
2
0.6
mA
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LT1097
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APPLICATIONS INFORMATION
The availability of the compensation terminal permits the use
of feedforward frequency compensation to enhance slew
rate. The voltage follower feedforward scheme bypasses the
amplifier’s gain stages and slews at nearly 10V/µs.
The inputs of the LT1097 are protected with back-to-back
diodes. In the voltage follower configuration, when the
input is driven by a fast, large signal pulse (>1V), the input
Follower Feedforward
Compensation
protection diodes effectively short the output to the input
during slewing, and a current, limited only by the output
short circuit protection will flow through the diodes.
The use of a feedback resistor, as shown in the voltage
follower feedforward diagram, is recommended because
this resistor keeps the current below the short circuit limit,
resulting in faster recovery and settling of the output.
Pulse Response of Feedforward
Compensation
Test Circuit for Offset Voltage and
its Drift with Temperature
50pF
50k*
15V
10k
5k
IN
5V/DIV
2
–
LT1097
3
2
+
6
100Ω*
OUT
5
50k*
1097 G20
5µs/DIV
7
LT1097
3
0.01µF
+
6
VO
4
–15V
VO = 1000VOS
*RESISTORS MUST HAVE LOW
THERMOELECTRIC POTENTIAL
LT1097•F03
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TYPICAL APPLICATIO
Low Power Comparator with