®
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DESCRIPTION
The OPA277 series precision op amps replace the industry
standard OP-177. They offer improved noise, wider output
voltage swing, and are twice as fast with half the quiescent
current. Features include ultra low offset voltage and drift, low
bias current, high common-mode rejection, and high power
supply rejection. Single, dual, and quad versions have identical
specifications for maximum design flexibility.
OPA277 series op amps operate from ±2V to ±18V supplies
with excellent performance. Unlike most op amps which
are specified at only one supply voltage, the OPA277 series
is specified for real-world applications; a single limit ap-
plies over the ±5V to ±15V supply range.
High performance
is maintained as the amplifiers swing to their specified limits.
Because the initial offset voltage (±20µV max) is so low, user
adjustment is usually not required. However, the single version
(OPA277) provides external trim pins for special applications.
OPA277 op amps are easy to use and free from phase inversion
and overload problems found in some other op amps. They are
stable in unity gain and provide excellent dynamic behavior
over a wide range of load conditions. Dual and quad versions
feature completely independent circuitry for lowest crosstalk
and freedom from interaction, even when overdriven or over-
loaded.
Single (OPA277) and dual (OPA2277) versions are available
in 8-pin DIP and SO-8 surface-mount packages. The quad
(OPA4277) comes in 14-pin DIP and SO-14 surface-mount
packages. All are fully specified from
–40°C to +85°C and
operate from –55°C to +125°C.
High Precision
OPERATIONAL AMPLIFIERS
FEATURES
● ULTRA LOW OFFSET VOLTAGE: 10µV
● ULTRA LOW DRIFT: ±0.1µV/°C
● HIGH OPEN-LOOP GAIN: 134dB
● HIGH COMMON-MODE REJECTION: 140dB
● HIGH POWER SUPPLY REJECTION: 130dB
● LOW BIAS CURRENT: 1nA max
● WIDE SUPPLY RANGE: ±2V to ±18V
● LOW QUIESCENT CURRENT: 800µA/amp
● SINGLE, DUAL, AND QUAD VERSIONS
● REPLACES OP-07, OP-77, OP-177
1
2
3
4
5
6
7
14
13
12
11
10
9
8
Out D
–In D
+In D
V–
+In C
–In C
Out C
Out A
–In A
+In A
V+
+In B
–In B
Out B
OPA4277
14-Pin DIP, SO-14
AD
BC
1
2
3
4
8
7
6
5
V+
Out B
–In B
+In B
Out A
–In A
+In A
V–
OPA2277
8-Pin DIP, SO-8
A
B
APPLICATIONS
●TRANSDUCER AMPLIFIER
●BRIDGE AMPLIFIER
● TEMPERATURE MEASUREMENTS
● STRAIN GAGE AMPLIFIER
●PRECISION INTEGRATOR
●BATTERY POWERED INSTRUMENTS
●TEST EQUIPMENT
1
2
3
4
8
7
6
5
Offset Trim
V+
Output
NC
Offset Trim
–In
+In
V–
OPA277
8-Pin DIP, SO-8
OPA277
OPA2277
OPA4277
OPA277
OPA2277
OPA277
OPA2277
OPA4277
OPA4277
© 1997 Burr-Brown Corporation PDS-1413D Printed in U.S.A. March, 1999
For most current data sheet and other product
information, visit www.burr-brown.com
2
®
OPA277, 2277, 4277
SPECIFICATIONS: VS = ±5V to VS = ±15V
At TA = +25°C, and RL = 2kΩ, unless otherwise noted.
Boldface limits apply over the specified temperature range, –40°C to +85°C.
OPA277PA, UA
OPA277P, U OPA2277PA, UA
OPA2277P, U OPA4277PA, UA
PARAMETER CONDITION MIN TYP(1) MAX MIN TYP(1) MAX UNITS
OFFSET VOLTAGE
Input Offset Voltage: VOS
OPA277P, U (high grade, single) ±10 ±20 µV
OPA2277P, U (high grade, dual) ±10 ±25 µV
All PA, UA Versions ±20 ±50 µV
Input Offset Voltage Over Temperature
OPA277P, U (high grade, single) TA = –40°C to +85°C±30 µV
OPA2277P, U (high grade, dual) TA = –40°C to +85°C±50 µV
All PA, UA Versions TA = –40°C to +85°C±100 µV
Input Offset Voltage Drift dVOS/dT
OPA277P, U (high grade, single) TA = –40°C to +85°C±0.1 ±0.15 µV/°C
OPA2277P, U (high grade, dual) TA = –40°C to +85°C±0.1 ±0.25 µV/°C
All PA, UA Versions TA = –40°C to +85°C±0.15 ±1µV/°C
Input Offset Voltage: (all models)
vs Time 0.2 ✻µV/mo
vs Power Supply PSRR VS = ±2V to ±18V ±0.3 ±0.5 ✻±1µV/V
TA = –40°C to +85°CVS = ±2V to ±18V ±0.5 ±1µV/V
Channel Separation (dual, quad) dc 0.1 ✻µV/V
INPUT BIAS CURRENT
Input Bias Current IB±0.5 ±1✻±2.8 nA
TA = –40°C to +85°C±2±4nA
Input Offset Current IOS ±0.5 ±1✻±2.8 nA
TA = –40°C to +85°C±2±4nA
NOISE
Input Voltage Noise, f = 0.1 to 10Hz 0.22 ✻µVp-p
0.035 ✻µVrms
Input Voltage Noise Density, f = 10Hz en12 ✻nV/√Hz
f = 100Hz 8 ✻nV/√Hz
f = 1kHz 8 ✻nV/√Hz
f = 10kHz 8 ✻nV/√Hz
Current Noise Density, f = 1kHz in0.2 ✻pA/√Hz
INPUT VOLTAGE RANGE
Common-Mode Voltage Range VCM (V–) +2 (V+) –2 ✻✻V
Common-Mode Rejection CMRR VCM = (V–) +2V to (V+) –2V 130 140 115 ✻dB
TA = –40°C to +85°CVCM = (V–) +2V to (V+) –2V 128 115 dB
INPUT IMPEDANCE
Differential 100 || 3 ✻MΩ || pF
Common-Mode VCM = (V–) +2V to (V+) –2V 250 || 3 ✻GΩ || pF
OPEN-LOOP GAIN
Open-Loop Voltage Gain AOL
V
O
= (V–)+0.5V to (V+)–1.2V, R
L
= 10kΩ
140 ✻dB
V
O
= (V–)+0.5V to (V+)–1.5V, R
L
= 2kΩ
126 134 ✻✻ dB
TA = –40°C to +85°C
V
O
= (V–)+0.5V to (V+)–1.5V, R
L
= 2kΩ
126 ✻dB
FREQUENCY RESPONSE
Gain-Bandwidth Product GBW 1 ✻MHz
Slew Rate SR 0.8 ✻V/µs
Settling Time, 0.1% VS = ±15V, G = 1, 10V Step 14 ✻µs
0.01% VS = ±15V, G = 1, 10V Step 16 ✻µs
Overload Recovery Time VIN • G = VS3✻µs
Total Harmonic Distortion + Noise THD+N 1kHz, G = 1, VO = 3.5Vrms 0.002 ✻%
OUTPUT
Voltage Output VORL = 10kΩ(V–) +0.5 (V+) –1.2 ✻✻V
TA = –40°C to +85°CRL = 10k Ω(V–) +0.5 (V+) –1.2 ✻✻V
RL = 2kΩ(V–) +1.5 (V+) –1.5 ✻✻V
TA = –40°C to +85°CRL = 2kΩ(V–) +1.5 (V+) –1.5 ✻✻V
Short-Circuit Current ISC ±35 ✻mA
Capacitive Load Drive CLOAD See Typical Curve ✻
The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes
no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change
without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant
any BURR-BROWN product for use in life support devices and/or systems.
3
OPA277, 2277, 4277
®
POWER SUPPLY
Specified Voltage Range VS±5±15 ✻✻V
Operating Voltage Range ±2±18 ✻✻V
Quiescent Current (per amplifier) IQIO = 0 ±790 ±825 ✻✻µA
TA = –40°C to +85°CIO = 0 ±900 ✻µA
TEMPERATURE RANGE
Specified Range –40 85 ✻✻°C
Operating Range –55 125 ✻✻°C
Storage Range –55 125 ✻✻°C
Thermal Resistance
θ
JA
SO-8 Surface-Mount 150 ✻°C/W
8-Pin DIP 100 ✻°C/W
14-Pin DIP 80 ✻°C/W
SO-14 Surface-Mount 100 ✻°C/W
✻ Specifications same as OPA277P, U.
NOTE: (1) VS = ±15V.
SPECIFICATIONS: VS = ±5V to VS = ±15V (CONT)
At TA = +25°C, and RL = 2kΩ, unless otherwise noted.
Boldface limits apply over the specified temperature range, –40°C to +85°C.
OPA277PA, UA
OPA277P, U OPA2277PA, UA
OPA2277P, U OPA4277PA, UA
PARAMETER CONDITION MIN TYP(1) MAX MIN TYP(1) MAX UNITS
ABSOLUTE MAXIMUM RATINGS(1)
Supply Voltage .................................................................................... 36V
Input Voltage .....................................................(V–) –0.7V to (V+) +0.7V
Output Short-Circuit(2) .............................................................. Continuous
Operating Temperature ..................................................–55 °C to +125°C
Storage Temperature .....................................................–55°C to +125°C
Junction Temperature...................................................................... 150°C
Lead Temperature (soldering, 10s)................................................. 300°C
NOTE: (1) Stresses above these rating may cause permanent damage.
Exposure to absolute maximum conditions for extended periods may degrade
device reliability. (2) Short-circuit to ground, one amplifier per package.
ELECTROSTATIC
DISCHARGE SENSITIVITY
This integrated circuit can be damaged by ESD. Burr-Brown
recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling
and installation procedures can cause damage.
ESD damage can range from subtle performance degrada-
tion to complete device failure. Precision integrated circuits
may be more susceptible to damage because very small
parametric changes could cause the device not to meet its
published specifications.
PACKAGE/ORDERING INFORMATION
OFFSET OFFSET PACKAGE
VOLTAGE VOLTAGE DRIFT DRAWING TEMPERATURE ORDERING TRANSPORT
PRODUCT max, µV max, µV/°C PACKAGE NUMBER(1) RANGE NUMBER(2) MEDIA
Single
OPA277PA ±50 ±1 8-Pin DIP 006 –40°C to +85°C OPA277PA Rails
OPA277P ±20 ±0.15 8-Pin DIP 006 –40°C to +85°C OPA277P Rails
OPA277UA ±50 ±1 SO-8 Surface Mount 182 –40°C to +85°C OPA277UA Rails
" " " " " " OPA277UA/2K5 Tape and Reel
OPA277U ±20 ±0.15 SO-8 Surface Mount 182 –40°C to +85°C OPA277U Rails
" " " " " " OPA277U/2K5 Tape and Reel
Dual
OPA2277PA ±50 ±1 8-Pin DIP 006 –40°C to +85°C OPA2277PA Rails
OPA2277P ±25 ±0.25 8-Pin DIP 006 –40°C to +85°C OPA2277P Rails
OPA2277UA ±50 ±1 SO-8 Surface Mount 182 –40°C to +85°C OPA2277UA Rails
" " " " " " OPA2277UA/2K5 Tape and Reel
OPA2277U ±25 ±0.25 SO-8 Surface Mount 182 –40°C to +85°C OPA2277U Rails
" " " " " " OPA2277U/2K5 Tape and Reel
Quad
OPA4277PA ±50 ±1 14-Pin DIP 010 –40°C to +85°C OPA4277PA Rails
OPA4277UA ±50 ±1 SO-14 Surface Mount 235 –40°C to +85°C OPA4277UA Rails
" " " " " " OPA4277UA/2K5 Tape and Reel
NOTE: (1) For detailed drawing and dimension table, please see end of data sheet, or Appendix C of Burr-Brown IC Data Book. (2) Products followed by a slash
(/) are only available in Tape and Reel in the quantities indicated (e.g. /2K5 indicates 2500 devices per reel). Ordering 2500 pieces of “OPA277UA/2K5” will get
a single 2500 piece Tape and Reel. For detailed Tape and Reel mechanical information, refer to Appendix B of Burr-Brown IC Data Book.
4
®
OPA277, 2277, 4277
TYPICAL PERFORMANCE CURVES
At TA = +25°C, VS = ±15V, and RL = 2kΩ, unless otherwise noted.
50nV/div
1sec/div
INPUT NOISE VOLTAGE vs TIME
10 100 1k 10k 100k
Frequency (Hz)
CHANNEL SEPARATION vs FREQUENCY
1M
140
120
100
80
60
40
Channel Separation (dB)
Dual and quad devices. G = 1,
all channels. Quad measured
channel A to D or B to C—other
combinations yield similar or
improved rejection.
10 100 1k 10k 100k
1
0.1
0.01
0.001
THD+Noise (%)
Frequency (Hz)
TOTAL HARMONIC DISTORTION + NOISE
vs FREQUENCY
V
OUT
= 3.5Vrms
G = 10, R
L
= 2kΩ, 10kΩ
G = 1, R
L
= 2kΩ, 10kΩ
Noise signal is bandwidth limited to
lie between 0.1Hz and 10Hz.
1 10 100 1k 10k
1000
100
10
1
Voltage Noise (nV/√Hz)
Current Noise (fA/√Hz)
Frequency (Hz)
INPUT NOISE AND CURRENT NOISE
SPECTRAL DENSITY vs FREQUENCY
Current Noise
Voltage Noise
0.1 1 10 100 1k 10k 100k 1M 10M
140
120
100
80
60
40
20
0
–20
A
OL
(dB)
0
–30
–60
–90
–120
–150
–180
Phase (°)
Frequency (Hz)
OPEN-LOOP GAIN/PHASE
vs FREQUENCY
G
φ
C
L
= 0
C
L
= 1500pF
0.1 1 10 100 1k 10k 100k 1M
140
120
100
80
60
40
20
0
PSR, CMR (dB)
Frequency (Hz)
POWER SUPPLY AND COMMON-MODE
REJECTION vs FREQUENCY
+PSR
CMR
–PSR
5
OPA277, 2277, 4277
®
TYPICAL PERFORMANCE CURVES (CONT)
At TA = +25°C, VS = ±15V, and RL = 2kΩ, unless otherwise noted.
OFFSET VOLTAGE PRODUCTION DISTRIBUTION
Percent of Amplifiers (%)
Offset Voltage (µV)
–50–45–40–35–30–25–20–15–10 –5 0 5 10 15 20 25 30 35 40 45 50
16
14
12
10
8
6
4
2
0
Typical distribution
of packaged units.
Single, dual, and
quad included.
3
2
1
0
–1
–2
–3
Offset Voltage Change (µV)
0 30 60 90 120
Time from Power Supply Turn-On (s)
WARM-UP OFFSET VOLTAGE DRIFT
15 45 75 105
OFFSET VOLTAGE DRIFT
PRODUCTION DISTRIBUTION
Percent of Amplifiers (%)
Offset Voltage (µV/°C)
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
35
30
25
20
15
10
5
0
Typical distribution
of packaged units.
Single, dual, and
quad included.
INPUT BIAS CURRENT vs TEMPERATURE
125
Temperature (°C)
–75 –50 –25 0 25 50 75 100
5
4
3
2
1
0
–1
–2
–3
–4
–5
Input Bias Current (nA)
Curves represent typical
production units.
–75 –50 –25 0 25 50 75 100 125
160
150
140
130
120
110
100
A
OL
, CMR, PSR (dB)
Temperature (°C)
A
OL
, CMR, PSR vs TEMPERATURE
CMR
A
OL
PSR
–75 –50 –25 0 25 50 75 100 125
1000
950
900
850
800
750
700
650
600
550
500
Quiescent Current (µA)
100
90
80
70
60
50
40
30
20
10
0
Short-Circuit Current (mA)
Temperature (°C)
QUIESCENT CURRENT AND
SHORT-CIRCUIT CURRENT vs TEMPERATURE
+I
SC
–I
SC
±I
Q
6
®
OPA277, 2277, 4277
TYPICAL PERFORMANCE CURVES (CONT)
At TA = +25°C, VS = ±15V, and RL = 2kΩ, unless otherwise noted.
CHANGE IN INPUT BIAS CURRENT
vs POWER SUPPLY VOLTAGE
40
Supply Voltage (V)
0 5 10 15 20 25 30 35
2.0
1.5
1.0
0.5
0.0
–0.5
–1.0
–1.5
–2.0
∆I
B
(nA)
Curve shows normalized change in
bias current with respect to V
S
= ±10V
(+20V). Typical I
B
may range from
–0.5nA to +0.5nA at V
S
= ±10V.
V
CM
= 0V
CHANGE IN INPUT BIAS CURRENT
vs COMMON-MODE VOLTAGE
15
Common-Mode Voltage (V)
–15 –10 –5 0 5 10
2.0
1.5
1.0
0.5
0.0
–0.5
–1.0
–1.5
–2.0
∆I
B
(nA)
V
S
= ±5V
V
S
= ±15V
Curve shows normalized change in bias current
with respect to V
CM
= 0V. Typical I
B
may range
from –05.nA to +0.5nA at V
CM
= 0V.
OUTPUT VOLTAGE SWING vs OUTPUT CURRENT
(V+)
(V+) – 1
(V+) – 2
(V+) – 3
(V+) – 4
(V+) – 5
(V–) + 5
(V–) + 4
(V–) + 3
(V–) + 2
(V–) + 1
(V–) 0 ±5 ±10 ±15 ±20 ±25 ±30
Output Current (mA)
Output Voltage Swing (V)
–55°C
–55°C
125°C
25°C
125°C 25°C
1000
900
800
700
600
500
Quiescent Current (µA)
0 ±5 ±10 ±15 ±20
Supply Voltage (V)
QUIESCENT CURRENT vs SUPPLY VOLTAGE
per amplifier
MAXIMUM OUTPUT VOLTAGE
vs FREQUENCY
1M
Frequency (Hz)
1k 10k 100k
30
25
20
15
10
5
0
Output Voltage (Vp-p)
V
S
= ±15V
V
S
= ±5V
100
10
20
50
Settling Time (µs)
±1 ±10 ±100
Gain (V/V)
SETTLING TIME vs CLOSED-LOOP GAIN
0.01%
10V step
C
L
= 1500pF
0.1%
7
OPA277, 2277, 4277
®
TYPICAL PERFORMANCE CURVES (CONT)
At TA = +25°C, VS = ±15V, and RL = 2kΩ, unless otherwise noted.
2V/div
20mV/div
20mV/div
10µs/div
1µs/div 1µs/div
SMALL-SIGNAL STEP RESPONSE
G = +1, CL = 0, VS = ±15V SMALL-SIGNAL STEP RESPONSE
G = +1, CL = 1500pF, VS = ±15V
LARGE-SIGNAL STEP RESPONSE
G = +1, CL = 1500pF, VS = ±15V
SMALL-SIGNAL OVERSHOOT
vs LOAD CAPACITANCE
1k10010 10k 100k
Load Capacitance (pF)
60
50
40
30
20
10
0
Overshoot (%)
Gain = –1
Gain = +1
Gain = ±10
8
®
OPA277, 2277, 4277
Op Amp
(a)
OPA277
(b)
No bias current
cancellation resistor
(see text)
Conventional op amp with external bias
current cancellation resistor. OPA277 with no external bias current
cancellation resistor.
R
2
R
1
R
2
R
1
R
B
= R
2
|| R
1
APPLICATIONS INFORMATION
The OPA277 series is unity-gain stable and free from unex-
pected output phase reversal, making it easy to use in a wide
range of applications. Applications with noisy or high im-
pedance power supplies may require decoupling capacitors
close to the device pins. In most cases 0.1µF capacitors are
adequate.
The OPA277 series has very low offset voltage and drift. To
achieve highest performance, circuit layout and mechanical
conditions should be optimized. Offset voltage and drift can
be degraded by small thermoelectric potentials at the op amp
inputs. Connections of dissimilar metals will generate ther-
mal potential which can degrade the ultimate performance of
the OPA277 series. These thermal potentials can be made to
cancel by assuring that they are equal in both input termi-
nals.
• Keep thermal mass of the connections made to the two
input terminals similar.
• Locate heat sources as far as possible from the critical
input circuitry.
• Shield op amp and input circuitry from air currents such as
cooling fans.
OPERATING VOLTAGE
OPA277 series op amp operate from ±2V to ±18V supplies
with excellent performance. Unlike most op amps which are
specified at only one supply voltage, the OPA277 series is
specified for real-world applications; a single limit applies
over the ±5V to ±15V supply range. This allows a customer
operating at VS = ±10V to have the same assured perfor-
mance as a customer using ±15V supplies. In addition, key
parameters are guaranteed over the specified temperature
range, –40°C to +85°C. Most behavior remains unchanged
through the full operating voltage range (±2V to ±18V).
Parameters which vary significantly with operating voltage
or temperature are shown in typical performance curves.
OFFSET VOLTAGE ADJUSTMENT
The OPA277 series is laser-trimmed for very low offset
voltage and drift so most circuits will not require external
adjustment. However, offset voltage trim connections are
provided on pins 1 and 8. Offset voltage can be adjusted by
connecting a potentiometer as shown in Figure 1. This
adjustment should be used only to null the offset of the op
amp. This adjustment should not be used to compensate for
offsets created elsewhere in a system since this can intro-
duce additional temperature drift.
INPUT PROTECTION
The inputs of the OPA277 series are protected with 1kΩ
series input resistors and diode clamps. The inputs can
withstand ±30V differential inputs without damage. The
protection diodes will, of course, conduct current when the
inputs are over-driven. This may disturb the slewing behav-
ior of unity-gain follower applications, but will not damage
the op amp.
INPUT BIAS CURRENT CANCELLATION
The input stage base current of the OPA277 series is inter-
nally compensated with an equal and opposite cancellation
circuit. The resulting input bias current is the difference
between the input stage base current and the cancellation
current. This residual input bias current can be positive or
negative.
When the bias current is canceled in this manner, the input
bias current and input offset current are approximately the
same magnitude. As a result, it is not necessary to use a bias
current cancellation resistor as is often done with other op
amps (Figure 2). A resistor added to cancel input bias
current errors may actually increase offset voltage and noise.
FIGURE 2. Input Bias Current Cancellation.
V+
V–
20kΩ
OPA277 single op amp only.
Use offset adjust pins only to null
offset voltage of op amp—see text.
Trim Range: Exceeds
Offset Voltage Specification
OPA277 6
7
8
4
3
21
0.1µF
0.1µF
FIGURE 1. OPA277 Offset Voltage Trim Circuit.
9
OPA277, 2277, 4277
®
R
1
V–
1/2
OPA2277
R
2
1/2
OPA2277 V
OUT
= (V
1
– V
2
)(1 + )
R
2
R
1
V+
V+
V–
R
2
For integrated solution see: INA126, INA2126 (dual)
INA125 (on-board reference)
INA122 (single-supply)
R
1
Load
Cell
R+∆R
V
2
R–∆R
R–∆RR+∆R
V
1
14
1
12
5V
11
13
I
REG
∼ 1mA
4
3
2
6
R
G
1250ΩXTR105
1/2
OPA2277 7
R
G
R
G
V
IN
–
V
IN
+
V
REG
I
R2
V+
I
RET
I
O
E
B
8
I
O
= 4mA + (V
IN
– V
IN
)
+–
40
R
G
9
10
R
F
10kΩ
R
412Ω
1/2
OPA2277
V+
V–
Type J
25Ω
(G = 1 + = 50)
2R
F
R
50Ω
1kΩ
R
F
10kΩ
I
R1
V
LIN
R
CM
= 1250Ω
0.01µF
FIGURE 3. Load Cell Amplifier.
FIGURE 4. Thermocouple Low Offset, Low Drift Loop Measurement with Diode Cold Junction Compensation.
