PIN CONNECTIONS
REV. C
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices.
a
Ultraprecision
Operational Amplifier
OP177
FEATURES
Ultralow Offset Voltage:
T
A
= 25 C: 25 V Max
Outstanding Offset Voltage Drift: 0.1 V/ C Max
Excellent Open-Loop Gain and Gain Linearity:
12 V/ V Typ
CMRR: 130 dB Min
PSRR: 115 dB Min
Low Supply Current: 2.0 mA Max
Fits Industry Standard Precision Op Amp Sockets
(OP07/OP77)
GENERAL DESCRIPTION
The OP177 features the highest precision performance of any
op amp currently available. Offset voltage of the OP177 is only
25
V max at room temperature. The ultralow V
OS
of the
OP177 combines with its exceptional offset voltage drift
(TCV
OS
) of 0.1
V/C max to eliminate the need for external
V
OS
adjustment and increases system accuracy over
temperature.
The OP177's open-loop gain of 12 V/
V is maintained over the
full
10 V output range. CMRR of 130 dB min, PSRR of
120 dB min, and maximum supply current of 2 mA are just a
few examples of the excellent performance of this operational
amplifier. The OP177's combination of outstanding specifications
ensures accurate performance in high closed-loop gain applications.
This low noise bipolar input op amp is also a cost effective
alternative to chopper-stabilized amplifiers. The OP177 provides
chopper-type performance without the usual problems of high
noise, low frequency chopper spikes, large physical size, limited
common-mode input voltage range, and bulky external storage
capacitors.
The OP177 is offered in the 40
C to +85C extended
industrial temperature ranges. This product is available in
8-pin epoxy DIPs, as well as the space saving 8-pin Small-
Outline (SO).
2B
C1
R7
(OPTIONA
L
NULL)
Q19
R2B*
R2A*
R1B
R1A
R9
R10
OUTPUT
R8
R6
C3
C2
Q13
Q17
R5
Q27
Q26
Q25
Q8
Q7
Q23
Q24
Q21
Q22
Q9
Q4
Q6
Q3
Q5
R3
R4
Q1
Q2
Q11
Q12
Q14
Q10
Q16
Q15
Q18
Q20
V+
V
NONINVERTING
INPUT
INVERTING
INPUT
*NOTE:
R2A AND R2B ARE ELECTRONICALLY ADJUSTED ON CHIP AT FACTORY.
Figure 1. Simplified Schematic
Epoxy Mini-DIP
(P Suffix)
8-Pin SO
(S-Suffix)
8
7
6
5
1
2
3
4
NC = NO CONNECT
V
OS
TRIM
IN
+IN
V
OS
TRIM
V+
OUT
NC
V
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
www.analog.com
Fax: 781/326-8703
Analog Devices, Inc., 2002
OP177
REV. C
2
OP177F
OP177G
Parameter
Symbol Conditions
Min
Typ
Max
Min
Typ
Max
Unit
INPUT OFFSET
VOLTAGE
V
OS
10
25
20
60
V
LONG-TERM
INPUT OFFSET
Voltage Stability
V
OS
/Time
0.3
0.4
V/Mo
INPUT OFFSET
1
CURRENT
I
OS
0.3
1.5
0.3
2.8
nA
INPUT BIAS
CURRENT
I
B
0.2
1.2
2
0.2
1.2
2.8
nA
INPUT NOISE
VOLTAGE
e
n
f
o
= 1 Hz to 100 Hz
2
118
150
118
150
nV rms
INPUT NOISE
CURRENT
i
n
f
o
= 1 Hz to 100 Hz
2
3
8
3
8
pA rms
INPUT
RESISTANCE
Differential-
Mode
3
R
IN
26
45
18.5
45
M
INPUT
RESISTANCE
COMMON-MODE
R
INCM
200
200
G
INPUT VOLTAGE
RANGE
4
IVR
13
14
13
14
V
COMMON-MODE
REJECTION
RATIO
CMRR
V
CM
=
13 V
130
140
115
140
dB
POWER SUPPLY
REJECTION
RATIO
PSRR
V
S
=
3 V to 18 V
115
125
110
120
dB
LARGE SIGNAL
VOLTAGE GAIN
A
VO
R
L
2 k
,
5000
12000
2000
6000
V/mV
V
O
= 610 V
5
OUTPUT
VOLTAGE
SWING
V
O
R
L
10 k
13.5 14.0
13.5 14.0
V
R
L
2 k
12.5 13.0
12.5 13.0
V
R
L
1 k
12.0 12.5
12.0 12.5
V
SLEW RATE
2
SR
R
L
2 k
0.1
0.3
0.1
0.3
V/
s
CLOSED-LOOP
BANDWIDTH
2
BW
A
VCL
= 1
0.4
0.6
0.4
0.6
MHz
OPEN-LOOP
OUTPUT
RESISTANCE
R
O
60
60
ELECTRICAL CHARACTERISTICS
(@ V
S
= 15 V, T
A
= 25 C, unless otherwise noted.)
OP177
REV. C
3
POWER
CONSUMPTION
P
D
V
S
=
15 V,
No Load
50
60
50
60
mW
Vs =
3 V,
No Load
3.5
4.5
3.5
4.5
mW
SUPPLY
CURRENT
I
SY
V
S
=
15 V,
No Load
1.6
2
1.6
2
mA
OFFSET
ADJUSTMENT
RANGE
R
P
= 20 k
3
3
mV
NOTES
1
Long-Term Input Offset Voltage Stability refers to the averaged trend line of V
OS
versus time over extended periods after the first 30 days of operation. Excluding the
initial hour of operation, changes in V
OS
during the first 30 operating days are typically less than 2.0
V.
2
Sample tested.
3
Guaranteed by design.
4
Guaranteed by CMRR test condition.
5
To ensure high open-loop gain throughout the
10 V output range, A
VO
is tested at 10 V
V
O
0 V, 0 V V
O
+10 V, and 10 V V
O
+10 V.
Specifications subject to change without notice.
OP177SPECIFICATIONS
REV. C
4
ELECTRICAL CHARACTERISTICS
OP177F
OP177G
Parameter
Symbol Conditions
Min Typ Max Min
Typ
Max Unit
INPUT OFFSET VOLTAGE
V
OS
15
40
20
100
V
AVERAGE INPUT OFFSET
VOLTAGE DRIFT
1
TCV
OS
0.1
0.3
0.7
1.2
V/C
INPUT OFFSET CURRENT
I
OS
0.5
2.2
0.5
4.5
nA
AVERAGE INPUT OFFSET
CURRENT DRIFT
2
TCI
OS
1.5
40
1.5
85
pA/
C
INPUT BIAS CURRENT
I
B
0.2
2.4
4
2.4
6
nA
AVERAGE INPUT BIAS
CURRENT DRIFT
2
TCI
B
8
40
15
60
pA/
C
INPUT VOLTAGE RANGE
3
IVR
13
13.5
13
13.5
V
COMMON-MODE
REJECTION RATIO
CMRR
V
CM
=
13 V
120
140
110
140
dB
POWER SUPPLY
REJECTION RATIO
PSSR
V
S
=
3 V to 18 V
110
120
106
115
dB
LARGE-SIGNAL
VOLTAGE GAIN
4
A
VO
R
L
2 k
, V
O
= 10 V
2000
6000
1000
4000
V/mV
OUTPUT VOLTAGE SWING V
O
R
L
2/k
12
13
12
13
V
POWER CONSUMPTION
P
D
V
S
=
15 V, No Load
60
75
60 75
mW
SUPPLY CURRENT
I
SY
V
S
=
15 V, No Load
20
2.5
2
2.5
mA
NOTES
1
OP177TCV
OS
is sample tested.
2
Guaranteed by endpoint limits.
3
Guaranteed by CMRR test condition.
4
To ensure high open-loop gain throughout the
10 V output range, A
VO
is tested at 10 V
V
O
0 V, 0 V V
O
+10 V, and 10 V V
O
+10 V.
Specifications subject to change without notice.
OP177
200k
50
V
O
V
OS
=
VO
4000
+
Figure 2. Typical Offset Voltage Test Circuit
OP177
20k
V+
OUTPUT
+
+
INPUT
V
OS
TRIM RANGE IS
TYPICALLY 3.0mV
V
Figure 3. Optional Offset Nulling Circuit
(@ V
S
= 15 V, 40 C
T
A
85 C, unless otherwise noted.)
OP177
REV. C
5
ABSOLUTE MAXIMUM RATINGS
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22 V
Internal Power Dissipation
1
. . . . . . . . . . . . . . . . . . . 500 mW
Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . .
30 V
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22 V
Output Short-Circuit Duration . . . . . . . . . . . . . . . . Indefinite
Storage Temperature Range
S, P Package . . . . . . . . . . . . . . . . . . . . . . . 65
C to +125C
Operating Temperature Range
OP177F, OP177G . . . . . . . . . . . . . . . . . . 40
C to +85C
Lead Temperature Range (Soldering, 60 sec) . . . . . . . 300
C
DICE Junction Temperature (T
J
) . . . . . . . . 65
C to +150C
Package Type
JA
2
JC
Unit
8-Pin Plastic DIP (P)
103
43
C/W
8-Pin SO (S)
158
43
C/W
NOTES
1
For supply voltages less than
22 V, the absolute maximum input voltage is equal
to the supply voltage.
2
JA
is specified for worst-case mounting conditions, i.e.,
JA
is specified for
device in socket for P-DIP;
JA
is specified for device soldered to printed circuit
board for SO package.
ORDERING GUIDE
Temperature
Package
Package
Model
Range
Description
Option
OP177FP
40
C to +85C 8-Pin Plastic DIP N-8
OP177GP
40
C to +85C 8-Pin Plastic DIP N-8
OP177FS
40
C to +85C 8-Pin SO
SO-8
OP177GS
40
C to +85C 8-Pin SO
SO-8
OP177
20k
+
PINOUTS SHOWN FOR
P AND Z PACKAGES
20V
+20V
NULL
Figure 4. Burn-In Circuit
OP177Typical Performance Characteristics
REV. C
6
TPC 2. Power Consumption vs.
Power Supply
TPC 5. Open-Loop Gain
vs. Temperature
TPC 8. Input Offset Current
vs. Temperature
TPC 3. Warm-Up V
OS
Drift
(Normalized) Z Package
TPC 6. Open-Loop Gain vs.
Power Supply Voltage
TPC 9. Closed-Loop Response
for Various Gain Configurations
TPC 1. Gain Linearity (Input
Voltage vs. Output Voltage)
TPC 4. Offset Voltage Change
Due to Thermal Shock
TPC 7. Input Bias Current
vs. Temperature
OP177
REV. C
7
TPC 11. CMRR vs. Frequency
TPC 14. Input Wideband Noise
vs. Bandwidth (0.1 Hz to
Frequency Indicated)
TPC 12. PSRR vs. Frequency
TPC 15. Maximum Output Swing
vs. Frequency
TPC 10. Open-Loop
Frequency Response
TPC 13. Total Input Noise
Voltage vs. Frequency
TPC 16. Maximum Output Voltage
vs. Load Resistance
TPC 17. Output Short-Circuit
Current vs. Time
OP177
REV. C
8
APPLICATION INFORMATION
Gain Linearity
The actual open-loop gain of most monolithic op amps varies at
different output voltages. This nonlinearity causes errors in
high closed-loop gain circuits.
It is important to know that the manufacturer's A
VO
specifi-
cation is only a part of the solution, since all automated testers
use endpoint testing and, therefore, show only the average gain.
For example, Figure 5 shows a typical precision op amp with a
respectable open-loop gain of 650 V/mV. However, the gain is
not constant through the output voltage range, causing
nonlinear errors. An ideal op amp would show a horizontal
scope trace.
V
Y
V
X
10V
0V
+10V
Figure 5. Typical Precision Op Amp
V
Y
V
X
10V
0V
+10V
Figure 6. Output Gain Linearity Trace
OP177
+
V
Y
V
X
10k
10k
1M
10
R
L
V
IN
= 10V
Figure 7. Open-Loop Gain Linearity Test Circuit
Figure 6 shows the OP177's output gain linearity trace with its
truly impressive average A
VO
of 12000 V/mV. The output trace
is virtually horizontal at all points, assuring extremely high gain
accuracy. ADI also performs additional testing to ensure
consistent high open-loop gain at various output voltages.
Figure 7 is a simple open-loop gain test circuit for your own
evaluation.
THERMOCOUPLE AMPLIFIER WITH COLD-JUNCTION
COMPENSATION
An example of a precision circuit is a thermocouple amplifier
that must amplify very low level signals accurately without
introducing linearity and offset errors to the circuit. In this
circuit, an S-type thermocouple, which has a Seebeck coef-
ficient of 10.3
V/C, produces 10.3 mV of output voltage at
a temperature of 1000
C. The amplifier gain is set at 973.16.
Thus, it will produce an output voltage of 10.024 V. Extended
temperature ranges to beyond 1500
C can be accomplished by
reducing the amplifier gain. The circuit uses a low-cost diode to
sense the temperature at the terminating junctions and, in turn,
compensates for any ambient temperature change. The OP177,
with its high open-loop gain, plus low offset voltage and drift
combines to yield a very precision temperature sensing circuit.
Circuit values for other thermocouple types are shown in Table I.
Table I.
Thermo-
Seebeck
couple Type
Coefficient
R1
R2
R7
R9
K
39.2
V/C
110
5.76 k 102 k 269 k
J
50.2
V/C
100
4.02 k 80.6 k 200 k
S
10.3
V/C
100
20.5 k 392 k 1.07 M
OP177
V
OUT
+
15V
10 F
0.1 F
+15V
10 F
0.1 F
R
9
1.07M
0.05%
R
4
50
1%
R
5
100
(ZERO
ADJUST-
MENT)
ANALOG
GROUND
ANALOG
GROUND
R
7
392k
1%
10 F
R
8
1.0k
0.05%
R
1
100
1%
R
2
20.5k
1%
+
10 F
COPPER
COPPER
ISOTHERMAL
BLOCK
COLD-JUNCTION
COMPENSATION
R
3
47k
1%
REF01
2.2 F
+
+15V
6
4
2
10.000V
+
TYPES
ISOTHERMAL
COLD-
JUNCTIONS
Figure 8. Thermocouple Amplifier with Cold Junction
Compensation
PRECISION HIGH GAIN DIFFERENTIAL AMPLIFIER
The high gain, gain linearity, CMRR, and low TCV
OS
of the
OP177 make it possible to obtain performance not previously
available in single stage, very high gain amplifier applications.
See Figure 9.
For best CMR,
R1
R2
must equal
R3
R4
. In this example, with a
10 mV differential signal, the maximum errors are as listed in
Table II.
OP177
REV. C
9
Figure 9. Precision High Gain Differential Amplifier
Table II. High Gain Differential Amp Performance
Type
Amount
Common-Mode Voltage
0.1%/V
Gain Linearity, Worst Case
0.02%
TCV
OS
0.0003%/
C
TCI
OS
0.008%/
C
ISOLATING LARGE CAPACITIVE LOADS
The circuit in Figure 10 reduces maximum slew rate but allows
driving capacitive loads of any size without instability. Because
the 100
resistor is inside the feedback loop, its effect on
output impedance is reduced to insignificance by the high open-
loop gain of the OP177.
Figure 10. Isolating Capacitive Loads
Figure 11. Bilateral Current Source
Figure 12. Precision Absolute Value Amplifier
OP177
REV. C
10
BILATERAL CURRENT SOURCE
The current sources shown in Figure 11 will supply both
positive and negative current into a grounded load.
Note that Z
O
=
R5
R4
R2
+1
R5
+ R4
R2
R3
R1
and that for Z
O
to be infinite,
R5
+ R4
R2
must
=
R3
R1
PRECISION ABSOLUTE VALUE AMPLIFIER
The high gain and low TCV
OS
assure accurate operation with
inputs from microvolts to volts. In this circuit, the signal always
appears as a common-mode signal to the op amps. See Figure 12.
PRECISION POSITIVE PEAK DETECTOR
In Figure 13, the C
H
must be of polystyrene, Teflon,
* or
polyethylene to minimize dielectric absorption and leakage. The
droop rate is determined by the size of C
H
and the bias current
of the OP41.
PRECISION THRESHOLD DETECTOR/AMPLIFIER
In Figure 14, when V
IN
< V
TH
, amplifier output swings nega-
tive, reverse biasing diode D
1
. V
OUT
= V
TH
if R
L
=
. When
V
IN
V
TH
, the loop closes,
V
OUT
=V
TH
+ V
IN
V
TH
(
)
1
+
R
F
R
S
C
C
is selected to smooth the response of the loop.
*Teflon is a registered trademark of DuPont.
Figure 13. Precision Positive Peak Detector
Figure 14. Precision Threshold Detector/Amplifier
OP177
REV. C
11
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
8-Pin Plastic DIP
(N-8)
PIN 1
0.280 (7.11)
0.240 (6.10)
4
5
8
1
SEATING
PLANE
0.060 (1.52)
0.015 (0.38)
0.130
(3.30)
MIN
0.210
(5.33)
MAX
0.160 (4.06)
0.115 (2.93)
0.430 (10.92)
0.348 (8.84)
0.022 (0.558)
0.014 (0.356)
0.070 (1.77)
0.045 (1.15)
0.100
(2.54)
BSC
0.325 (8.25)
0.300 (7.62)
0.015 (0.381)
0.008 (0.204)
0.195 (4.95)
0.115 (2.93)
8-Pin SO
(SO-08)
0.0098 (0.25)
0.0075 (0.19)
0.0500 (1.27)
0.0160 (0.41)
8
0
0.0196 (0.50)
0.0099 (0.25)
x 45
PIN 1
0.1574 (4.00)
0.1497 (3.80)
0.2440 (6.20)
0.2284 (5.80)
4
5
1
8
0.0192 (0.49)
0.0138 (0.35)
0.0500
(1.27)
BSC
0.0688 (1.75)
0.0532 (1.35)
0.0098 (0.25)
0.0040 (0.10)
0.1968 (5.00)
0.1890 (4.80)
Revision History
Location
Page
01/30--Data Sheet changed from REV. B to REV. C.
Edits to FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Edits to GENERAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Edits to PIN CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Edits to ELECTRICAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2, 3
Global deletion of references to OP177E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3, 4, 10
Edits to ABSOLUTE MAXIMUM RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Edits to PACKAGE TYPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Edits to ORDERING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Edit to OUTLINE DIMENSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
C00289-0-2/02(C)
PRINTED IN U.S.A.
12
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