®
OPA 277 OPA 227 7
OPA
4277
OPA 277
OPA 2277
OPA 4277
OPA277 OPA2277 OPA4277
For most current data sheet and other product information, visit www.burr-brown.com
High Precision OPERATIONAL AMPLIFIERS
FEATURES
q ULTRA LOW OFFSET VOLTAGE: 10µV q ULTRA LOW DRIFT: ±0.1µV/°C q HIGH OPEN-LOOP GAIN: 134dB q HIGH COMMON-MODE REJECTION: 140dB q HIGH POWER SUPPLY REJECTION: 130dB q LOW BIAS CURRENT: 1nA max q WIDE SUPPLY RANGE: ±2V to ±18V q LOW QUIESCENT CURRENT: 800µA/amp q SINGLE, DUAL, AND QUAD VERSIONS q REPLACES OP-07, OP-77, OP-177
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 applies 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 overloaded. 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.
OPA4277 Out A 1 2 A D 12 11 10 B –In B 6 7 14-Pin DIP, SO-14 C 9 8 –In C Out C +In D V– +In C 3 4 5 14 13 Out D –In D
APPLICATIONS
q q q q q q q TRANSDUCER AMPLIFIER BRIDGE AMPLIFIER TEMPERATURE MEASUREMENTS STRAIN GAGE AMPLIFIER PRECISION INTEGRATOR BATTERY POWERED INSTRUMENTS TEST EQUIPMENT
OPA277 Offset Trim –In +In V– 1 2 3 4 8-Pin DIP, SO-8 8 7 6 5 Offset Trim V+ Output NC
OPA2277 1 2 3 4 8-Pin DIP, SO-8 A B 8 7 6 5
–In A
Out A –In A +In A V–
V+ Out B –In B +In B
+In A V+ +In B
Out B
IInternational Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111 Twx: 910-952-1111 • Internet: http://www.burr-brown.com/ • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132
© 1997 Burr-Brown Corporation
PDS-1413D
Printed in U.S.A. March, 1999
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 OPA2277PA, UA OPA4277PA, UA MAX MIN TYP(1) MAX UNITS OPA277P, U OPA2277P, U PARAMETER OFFSET VOLTAGE Input Offset Voltage: OPA277P, U (high grade, single) OPA2277P, U (high grade, dual) All PA, UA Versions VOS CONDITION MIN TYP(1)
± 10 ± 10
±20 ±25
±20
± 50
µV µV µV µV µV µV µV/°C µV/°C µV/°C µV/mo µV/V µV/V µV/V nA nA nA nA µVp-p µVrms nV/√Hz nV/√Hz nV/√Hz nV/√Hz pA/√Hz
Input Offset Voltage Over Temperature OPA277P, U (high grade, single) OPA2277P, U (high grade, dual) All PA, UA Versions Input Offset Voltage Drift dVOS/dT OPA277P, U (high grade, single) OPA2277P, U (high grade, dual) All PA, UA Versions Input Offset Voltage: (all models) vs Time vs Power Supply TA = –40°C to +85°C Channel Separation (dual, quad) INPUT BIAS CURRENT Input Bias Current TA = –40°C to +85°C Input Offset Current TA = –40°C to +85°C NOISE Input Voltage Noise, f = 0.1 to 10Hz Input Voltage Noise Density, f = 10Hz en f = 100Hz f = 1kHz f = 10kHz Current Noise Density, f = 1kHz in INPUT VOLTAGE RANGE Common-Mode Voltage Range Common-Mode Rejection TA = –40°C to +85°C INPUT IMPEDANCE Differential Common-Mode OPEN-LOOP GAIN Open-Loop Voltage Gain TA = –40°C to +85°C FREQUENCY RESPONSE Gain-Bandwidth Product GBW Slew Rate SR Settling Time, 0.1% 0.01% Overload Recovery Time Total Harmonic Distortion + Noise THD+N OUTPUT Voltage Output TA = –40°C to +85°C TA = –40°C to +85°C Short-Circuit Current Capacitive Load Drive VO AOL VCM CMRR
TA = –40°C to +85°C TA = –40°C to +85°C TA = –40°C to +85°C TA = –40°C to +85°C TA = –40°C to +85°C TA = –40°C to +85°C
±30 ±50 ±0.1 ±0.1 ±0.15 ±0.25
±100
±0.15
T T T
±1
±1 ±1
PSRR
VS = ±2V to ±18V VS = ±2V to ±18V dc
0.2 ± 0.3 0.1 ± 0.5 ± 0.5
±0.5 ±0.5
IB I OS
±2 ±2
±1 ±1
T T
± 2.8 ±4 ± 2.8 ±4
0.22 0.035 12 8 8 8 0.2 (V–) +2 130 128 (V+) –2 140 T 115 115
T T T T T T T T T
VCM = (V–) +2V to (V+) –2V VCM = (V–) +2V to (V+) –2V
V dB dB MΩ || pF GΩ || pF dB dB dB MHz V/µs µs µs µs %
VCM = (V–) +2V to (V+) –2V VO = (V–)+0.5V to (V+)–1.2V, RL = 10kΩ VO = (V–)+0.5V to (V+)–1.5V, RL = 2kΩ VO = (V–)+0.5V to (V+)–1.5V, RL = 2kΩ
100 || 3 250 || 3 140 134
T T T T
126 126
T T
VS = ±15V, G = 1, 10V Step VS = ±15V, G = 1, 10V Step VIN • G = VS 1kHz, G = 1, VO = 3.5Vrms RL = 10kΩ RL = 10kΩ RL = 2kΩ RL = 2kΩ (V–) (V–) (V–) (V–) +0.5 +0.5 +1.5 +1.5
1 0.8 14 16 3 0.002 (V+) (V+) (V+) (V+) –1.2 –1.2 –1.5 –1.5 T T T T
T T T T T T T T T T T T
I SC CLOAD
± 35 See Typical Curve
V V V V mA
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.
®
OPA277, 2277, 4277
2
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.
(CONT)
OPA277P, U OPA2277P, U PARAMETER POWER SUPPLY Specified Voltage Range Operating Voltage Range Quiescent Current (per amplifier) TA = –40°C to +85°C TEMPERATURE RANGE Specified Range Operating Range Storage Range Thermal Resistance SO-8 Surface-Mount 8-Pin DIP 14-Pin DIP SO-14 Surface-Mount T Specifications same as OPA277P, U. NOTE: (1) VS = ±15V. CONDITION MIN TYP(1) MAX
OPA277PA, UA OPA2277PA, UA OPA4277PA, UA MIN TYP(1) MAX UNITS
VS IQ IO = 0 IO = 0
±5 ±2
±790
±15 ±18 ±825 ±900 85 125 125
T T T
T T T T T T T
V V µA µA °C °C °C °C/W °C/W °C/W °C/W
–40 –55 –55
T T T T T T T
θJA
150 100 80 100
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 degradation 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 DRAWING NUMBER(1)
PACKAGE/ORDERING INFORMATION
OFFSET VOLTAGE max, µV ±50 ±20 ±50 " ±20 " ±50 ±25 ±50 " ±25 " ±50 ±50 " OFFSET VOLTAGE DRIFT max, µV/°C ±1 ±0.15 ±1 " ±0.15 " ±1 ±0.25 ±1 " ±0.25 " ±1 ±1 " TEMPERATURE RANGE –40°C to +85°C –40°C to +85°C –40°C to +85°C " –40°C to +85°C " –40°C to +85°C –40°C to +85°C –40°C to +85°C " –40°C to +85°C " –40°C to +85°C –40°C to +85°C " ORDERING NUMBER(2) TRANSPORT MEDIA
PRODUCT Single OPA277PA OPA277P OPA277UA " OPA277U " Dual OPA2277PA OPA2277P OPA2277UA " OPA2277U " Quad OPA4277PA OPA4277UA "
PACKAGE
8-Pin DIP 8-Pin DIP SO-8 Surface Mount " SO-8 Surface Mount "
006 006 182 " 182 "
OPA277PA OPA277P OPA277UA OPA277UA/2K5 OPA277U OPA277U/2K5
Rails Rails Rails Tape and Reel Rails Tape and Reel
8-Pin DIP 8-Pin DIP SO-8 Surface Mount " SO-8 Surface Mount "
006 006 182 " 182 "
OPA2277PA OPA2277P OPA2277UA OPA2277UA/2K5 OPA2277U OPA2277U/2K5
Rails Rails Rails Tape and Reel Rails Tape and Reel
14-Pin DIP SO-14 Surface Mount "
010 235 "
OPA4277PA OPA4277UA OPA4277UA/2K5
Rails Rails 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.
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3
OPA277, 2277, 4277
TYPICAL PERFORMANCE CURVES
At TA = +25°C, VS = ±15V, and RL = 2kΩ, unless otherwise noted.
OPEN-LOOP GAIN/PHASE vs FREQUENCY 140 120 100 G CL = 0 CL = 1500pF 0 –30
POWER SUPPLY AND COMMON-MODE REJECTION vs FREQUENCY 140 120 –PSR
PSR, CMR (dB)
+PSR
100 80 CMR 60 40 20 0
60 40 20 0 –20 0.1 1 10 100 1k 10k 100k 1M
–90 –120 –150 –180
Phase (°)
AOL (dB)
80
φ
–60
10M
0.1
1
10
100
1k
10k
100k
1M
Frequency (Hz)
Frequency (Hz)
INPUT NOISE AND CURRENT NOISE SPECTRAL DENSITY vs FREQUENCY 1000
INPUT NOISE VOLTAGE vs TIME
Voltage Noise (nV/√Hz) Current Noise (fA/√Hz)
Current Noise 100
Noise signal is bandwidth limited to lie between 0.1Hz and 10Hz. 50nV/div
10
Voltage Noise
1 1 10 100 Frequency (Hz) 1k 10k
1sec/div
CHANNEL SEPARATION vs FREQUENCY 140
1
TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY VOUT = 3.5Vrms
Channel Separation (dB)
120
THD+Noise (%)
0.1 G = 10, RL = 2kΩ, 10kΩ 0.01 G = 1, RL = 2kΩ, 10kΩ 0.001
100 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.
80
60
40 10 100 1k 10k 100k 1M Frequency (Hz)
10
100
1k Frequency (Hz)
10k
100k
®
OPA277, 2277, 4277
4
TYPICAL PERFORMANCE CURVES (CONT)
At TA = +25°C, VS = ±15V, and RL = 2kΩ, unless otherwise noted.
OFFSET VOLTAGE PRODUCTION DISTRIBUTION 16 14
Percent of Amplifiers (%)
OFFSET VOLTAGE DRIFT PRODUCTION DISTRIBUTION 35 30 Typical distribution of packaged units. Single, dual, and quad included.
12 10 8 6 4 2 0
Percent of Amplifiers (%)
Typical distribution of packaged units. Single, dual, and quad included.
25 20 15 10 5 0
–50–45–40–35–30–25–20–15–10 –5 0 5 10 15 20 25 30 35 40 45 50 Offset Voltage (µV)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Offset Voltage (µV/°C)
WARM-UP OFFSET VOLTAGE DRIFT 3
Offset Voltage Change (µV)
AOL, CMR, PSR vs TEMPERATURE 160 150
2 1 0 –1 –2 –3 0 15 30 45 60 75 90 105 120 Time from Power Supply Turn-On (s)
AOL, CMR, PSR (dB)
CMR 140 130 PSR 120 110 100 –75 AOL
–50
–25
0
25
50
75
100
125
Temperature (°C)
INPUT BIAS CURRENT vs TEMPERATURE 5 4
Input Bias Current (nA)
QUIESCENT CURRENT AND SHORT-CIRCUIT CURRENT vs TEMPERATURE 1000 950 100 90
Quiescent Current (µA)
3 2 1 0 –1 –2 –3 –4 –5 –75 –50 –25 0 25 50 75 100 125 Temperature (°C) Curves represent typical production units.
900 850 800 750 700 650 600 550 500 –75 –50 –25 0 25 50 75 100 –ISC +ISC ±IQ
70 60 50 40 30 20 10 0 125 Temperature (°C)
Short-Circuit Current (mA)
®
80
5
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 2.0 1.5 1.0 ∆IB (nA) 0.5 0.0 –0.5 –1.0 –1.5 –2.0 0 5 10 15 20 25 30 35 40 Supply Voltage (V) ∆IB (nA) VCM = 0V Curve shows normalized change in bias current with respect to VS = ±10V (+20V). Typical IB may range from –0.5nA to +0.5nA at VS = ±10V. 2.0 1.5 1.0 0.5 0.0 –0.5
CHANGE IN INPUT BIAS CURRENT vs COMMON-MODE VOLTAGE Curve shows normalized change in bias current with respect to VCM = 0V. Typical IB may range from –05.nA to +0.5nA at VCM = 0V. VS = ±5V
VS = ±15V –1.0 –1.5 –2.0 –15 –10 –5 0 5 10 15 Common-Mode Voltage (V)
QUIESCENT CURRENT vs SUPPLY VOLTAGE 1000 per amplifier
Quiescent Current (µA)
SETTLING TIME vs CLOSED-LOOP GAIN 100 10V step CL = 1500pF
Settling Time (µs)
900 50 0.01% 0.1%
800
700
20
600
500 0 ±5 ±10 Supply Voltage (V) ±15 ±20
10 ±1 ±10 Gain (V/V) ±100
MAXIMUM OUTPUT VOLTAGE vs FREQUENCY 30 25
Output Voltage (Vp-p)
OUTPUT VOLTAGE SWING vs OUTPUT CURRENT (V+) (V+) – 1 Output Voltage Swing (V) (V+) – 2 (V+) – 3 (V+) – 4 (V+) – 5 (V–) + 5 (V–) + 4 (V–) + 3 (V–) + 2 (V–) + 1 –55°C (V–) 125°C 125°C 25°C 25°C –55°C
VS = ±15V
20 15 10 VS = ±5V 5 0 1k 10k Frequency (Hz) 100k 1M
0
±5
±10
±15
±20
±25
±30
Output Current (mA)
®
OPA277, 2277, 4277
6
TYPICAL PERFORMANCE CURVES (CONT)
At TA = +25°C, VS = ±15V, and RL = 2kΩ, unless otherwise noted.
SMALL-SIGNAL OVERSHOOT vs LOAD CAPACITANCE 60 Gain = –1 50
LARGE-SIGNAL STEP RESPONSE G = +1, CL = 1500pF, VS = ±15V
Overshoot (%)
40 30 20 Gain = ±10 10 0 10 100 1k Load Capacitance (pF) 10k 100k
2V/div
Gain = +1
10µs/div
SMALL-SIGNAL STEP RESPONSE G = +1, CL = 0, VS = ±15V
SMALL-SIGNAL STEP RESPONSE G = +1, CL = 1500pF, VS = ±15V
20mV/div
1µs/div
20mV/div
1µs/div
®
7
OPA277, 2277, 4277
APPLICATIONS INFORMATION
The OPA277 series is unity-gain stable and free from unexpected output phase reversal, making it easy to use in a wide range of applications. Applications with noisy or high impedance 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 thermal 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 terminals. • 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 performance 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
R2 R1 Op Amp
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 introduce additional temperature drift.
V+ Trim Range: Exceeds Offset Voltage Specification 0.1µF 20kΩ 7 2 3 0.1µF 1 8 OPA277 4 6 OPA277 single op amp only. Use offset adjust pins only to null offset voltage of op amp—see text.
V–
FIGURE 1. OPA277 Offset Voltage Trim Circuit. 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 behavior 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 internally 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.
R2 R1 OPA277
RB = R2 || R1
No bias current cancellation resistor (see text) (b) OPA277 with no external bias current cancellation resistor.
(a) Conventional op amp with external bias current cancellation resistor.
FIGURE 2. Input Bias Current Cancellation.
®
OPA277, 2277, 4277
8
V+
1/2 OPA2277 R2 V–
VOUT = (V1 – V2)(1 +
R2 R1
)
R–∆R V1 R+∆R Load Cell
R+∆R V2 R–∆R
V+ R1 1/2 OPA2277
V– R2 R1
For integrated solution see: INA126, INA2126 (dual) INA125 (on-board reference) INA122 (single-supply)
FIGURE 3. Load Cell Amplifier.
IREG ∼ 1mA 5V
12 V+ Type J 1/2 OPA2277 RF 10kΩ R 412Ω 13 VLIN
+ VIN
1 IR1
14 IR2
11 VREG
10 V+
4 RG 1250Ω 3
RG XTR105 RG
– VIN
RF 10kΩ
B E IO
9
8
1kΩ 50Ω 25Ω RCM = 1250Ω
1/2 OPA2277 V–
2
7 6
+ – IO = 4mA + (VIN – VIN) 40 RG
IRET
(G = 1 + 0.01µF
2RF = 50) R
FIGURE 4. Thermocouple Low Offset, Low Drift Loop Measurement with Diode Cold Junction Compensation.
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9
OPA277, 2277, 4277
