AD OP727ARU Precision micropower single-supply operational amplifier Datasheet

a
Precision Micropower
Single-Supply Operational Amplifiers
OP777/OP727/OP747
FEATURES
Low Offset Voltage: 100 V Max
Low Input Bias Current: 10 nA Max
Single-Supply Operation: 2.7 V to 30 V
Dual-Supply Operation: 1.35 V to 15 V
Low Supply Current: 300 A/Amp Max
Unity Gain Stable
No Phase Reversal
FUNCTIONAL BLOCK DIAGRAMS
14-Lead SOIC
(R-14)
8-Lead MSOP
(RM-8)
1
NC
IN
IN
V
8
NC
V+
OUT
NC
OP777
4
5
NC = NO CONNECT
APPLICATIONS
Current Sensing (Shunt)
Line or Battery-Powered Instrumentation
Remote Sensors
Precision Filters
OP727 SOIC Pin-Compatible with LT1013
GENERAL DESCRIPTION
The OP777 , OP727 , and OP747 are precision single , dual,
and quad rail-to-rail output single- supply amplifiers featuring
micropower operation and rail-to-rail output ranges. These
amplifier s provide improved performance over the industry -standard
OP07 with ± 15 V supplies , and offer the further advantage of true
single -supply operation down to 2.7 V , and smaller package
options than any other high-voltage precision bipolar amplifier.
Outputs are stable with capacitive loads of over 500 pF. Supply
current is less than 300 µA per amplifier at 5 V. 500 Ω series resistors protect the inputs, allowing input signal levels several volts above
the positive supply without phase reversal.
Applications for these amplifiers include both line-powered and
portable instrumentation, remote sensor signal conditioning, and
precision filters.
The OP777, OP727, and OP747 are specified over the extended
industrial (–40°C to +85°C) temperature range. The OP777,
single, is available in 8-lead MSOP and 8-lead SOIC packages.
The OP747, quad, is available in 14-lead TSSOP and narrow
14-lead SO packages. Surface-mount devices in TSSOP and MSOP
packages are available in tape and reel only.
The OP727, dual, is available in 8-lead TSSOP and 8-lead
SOIC packages. The OP727 8-lead SOIC pin configuration
differs from the standard 8-lead operational amplifier pinout.
OUT A 1
14
OUT D
–IN A 2
13
–IN D
IN A 3
12
IN D
V 4
V–
TOP VIEW
(Not to Scale) 10
IN B 5
IN C
8-Lead SOIC
(R-8)
NC 1
IN 2
OP777
–IN B 6
9
–IN C
OUT B 7
8
OUT C
14-Lead TSSOP
(RU-14)
7 V+
6 OUT
V 4
5 NC
NC = NO CONNECT
8-Lead TSSOP
(RU-8)
8
14
OUT D
–IN A 2
13
–IN D
IN A 3
12
IN D
OP747
TOP VIEW 11 V–
(Not to Scale) 10
IN B 5
IN C
–IN B 6
9
–IN C
7
8
OUT C
V
OUT B
7 OUT B
OP727
TOP VIEW
IN A 3 (Not to Scale) 6 –IN B
5
OUT A 1
V 4
–IN A 2
V– 4
11
8 NC
+IN 3
OUT A 1
OP747
IN B
8-Lead SOIC
(R-8)
IN A 1
8
OP727
–IN A
OUT A
TOP VIEW
IN B 3 (Not to Scale) 6 V
V– 2
–IN B 4
7
5
OUT B
NOTE: THIS PIN CONFIGURATION DIFFERS
FROM THE STANDARD 8-LEAD
OPERATIONAL AMPLIFIER PINOUT.
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.
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., 2001
OP777/OP727/OP747–SPECIFICATIONS
ELECTRICAL CHARACTERISTICS (@ V = 5.0 V, V
S
CM
= 2.5 V, TA = 25C unless otherwise noted.)
Parameter
Symbol
Conditions
INPUT CHARACTERISTICS
Offset Voltage OP777
VOS
IB
IOS
+25 C < T A < +85 C
–40°C < T A < +85 °C
+25 C < T A < +85 C
–40°C < T A < +85 °C
–40°C < T A < +85 °C
–40°C < T A < +85 °C
CMRR
AVO
∆VOS/∆T
∆VOS/∆T
VCM = 0 V to 4 V
RL = 10 k Ω , VO = 0.5 V to 4.5 V
–40°C < T A < +85 °C
–40°C < T A < +85 °C
OUTPUT CHARACTERISTICS
Output Voltage High
Output Voltage Low
Output Circuit
VOH
VOL
IOUT
IL = 1 mA, –40 °C to +85 °C
IL = 1 mA, –40 °C to +85 °C
VDROPOUT < 1 V
4.88
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current/Amplifier OP777
PSRR
ISY
VS = 3 V to 30 V
VO = 0 V
–40°C < T A < +85 °C
VO = 0 V
–40°C < T A < +85 °C
120
DYNAMIC PERFORMANCE
Slew Rate
Gain Bandwidth Product
SR
GBP
RL = 2 k Ω
0.2
0.7
V/µs
MHz
NOISE PERFORMANCE
Voltage Noise
Voltage Noise Density
Current Noise Density
enp-p
en
in
0.1 Hz to 10 Hz
f = 1 kHz
f = 1 kHz
0.4
15
0.13
µV p-p
nV/√Hz
pA/√Hz
Offset Voltage OP727/OP747
Input Bias Current
Input Offset Current
Input Voltage Range
Common-Mode Rejection Ratio
Large Signal Voltage Gain
Offset Voltage Drift OP777
Offset Voltage Drift OP727/OP747
Supply Current/Amplifier OP727/OP747
Min
0
104
300
Typ
Max
Unit
20
50
30
60
5.5
0.1
100
200
160
300
11
2
4
µV
µV
µV
µV
nA
nA
V
dB
V/mV
µV/°C
µV/°C
110
500
0.3
0.4
4.91
126
±10
130
220
270
235
290
1.3
1.5
140
V
mV
mA
270
320
290
350
dB
µA
µA
µA
µA
NOTES
Typical specifications: >50% of units perform equal to or better than the “typical” value.
Specifications subject to change without notice.
–2–
REV. C
OP777/OP727/OP747
ELECTRICAL CHARACTERISTICS (@ 15 V, V
CM
= 0 V, TA = 25C unless otherwise noted.)
Parameter
Symbol
Conditions
INPUT CHARACTERISTICS
Offset Voltage OP777
VOS
Offset Voltage OP727/OP747
VOS
Input Bias Current
Input Offset Current
Input Voltage Range
Common-Mode Rejection Ratio
Large Signal Voltage Gain
Offset Voltage Drift OP777
Offset Voltage Drift OP727/OP747
IB
IOS
+25 °C < T A < +85 °C
–40°C < T A < +85 °C
+25 °C < T A < +85 °C
–40°C < T A < +85 °C
–40°C < T A < +85 °C
–40°C < T A < +85 °C
CMRR
AVO
∆VOS/∆T
∆VOS/∆T
VCM = –15 V to +14 V
RL = 10 k Ω , V O = –14.5 V to +14.5 V
–40°C < T A < +85 °C
–40°C < T A < +85 °C
OUTPUT CHARACTERISTICS
Output Voltage High
Output Voltage Low
Output Circuit
VOH
VOL
IOUT
IL = 1 mA, –40 °C to +85 °C
IL = 1 mA, –40 °C to +85 °C
+14.9
+14.94
–14.94 –14.9
±30
V
V
mA
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current/Amplifier OP777
PSRR
ISY
VS = ± 1.5 V to ± 15 V
VO = 0 V
–40°C < T A < +85 °C
VO = 0 V
–40°C < T A < +85 °C
120
130
300
350
320
375
dB
µA
µA
µA
µA
DYNAMIC PERFORMANCE
Slew Rate
Gain Bandwidth Product
SR
GBP
RL = 2 k Ω
0.2
0.7
V/µs
MHz
NOISE PERFORMANCE
Voltage Noise
Voltage Noise Density
Current Noise Density
enp-p
en
in
0.1 Hz to 10 Hz
f = 1 kHz
f = 1 kHz
0.4
15
0.13
µV p-p
nV/√Hz
pA/√Hz
Supply Current/Amplifier OP727/747
Specifications subject to change without notice.
REV. C
–3–
Min
–15
110
1,000
Typ
Max
Unit
30
50
30
50
5
0.1
100
200
160
300
10
2
+14
µV
µV
µV
µV
nA
nA
V
dB
V/mV
µV/°C
µV/°C
120
2,500
0.3
0.4
1.3
1.5
350
400
375
450
OP777/OP727/OP747
ABSOLUTE MAXIMUM RATINGS 1, 2
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 V
Input Voltage . . . . . . . . . . . . . . . . . . . . –VS – 5 V to +VS + 5 V
Differential Input Voltage . . . . . . . . . . . . . . ± Supply Voltage
Output Short-Circuit Duration to GND . . . . . . . . . Indefinite
Storage Temperature Range
RM, R, RU Packages . . . . . . . . . . . . . . . . –65°C to +150°C
Operating Temperature Range
OP777/OP727/OP747 . . . . . . . . . . . . . . . –40°C to +85°C
Junction Temperature Range
RM, R, RU Packages . . . . . . . . . . . . . . . . –65°C to +150°C
Lead Temperature Range (Soldering, 60 sec) . . . . . . . 300°C
Electrostatic Discharge (Human Body Model) . . . . 2000 V max
Package Type
JA3
JC
Unit
8-Lead MSOP (RM)
8-Lead SOIC (R)
8-Lead TSSOP (RU)
14-Lead SOIC (R)
14-Lead TSSOP (RU)
190
158
240
120
180
44
43
43
36
35
°C/W
°C/W
°C/W
°C/W
°C/W
NOTES
1
Absolute maximum ratings apply at 25°C, unless otherwise noted.
2
Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the
device at these or any other conditions above those listed in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.
3
θJA is specified for worst-case conditions, i.e., θJA is specified for device soldered in
circuit board for surface-mount packages.
ORDERING GUIDE
Model
Temperature
Range
Package
Description
Package
Option
Branding
Information
OP777ARM
OP777AR
OP727ARU
OP727AR
OP747AR
OP747ARU
–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
8-Lead MSOP
8-Lead SOIC
8-Lead TSSOP
8-Lead SOIC
14-Lead SOIC
14-Lead TSSOP
RM-8
SO-8
RU-8
SO-8
R-14
RU-14
A1A
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection. Although
the OP777/OP727/OP747 features proprietary ESD protection circuitry, permanent damage may
occur on devices subjected to high-energy electrostatic discharges. Therefore, proper ESD
precautions are recommended to avoid performance degradation or loss of functionality.
–4–
WARNING!
ESD SENSITIVE DEVICE
REV. C
Typical Performance Characteristics– OP777/OP727/OP747
NUMBER OF AMPLIFIERS
180
160
140
120
100
80
60
VSY = 5V
VCM = 2.5V
TA = 25C
200
180
160
140
120
100
80
60
40
40
20
20
0
100 8060 4020 0 20 40 60 80 100
OFFSET VOLTAGE – V
0
100 8060 4020 0 20 40 60 80 100
OFFSET VOLTAGE – V
TPC 1. OP777 Input Offset Voltage
Distribution
TPC 2. OP777 Input Offset Voltage
Distribution
VSY = 15V
VCM = 0V
TA = –40C TO +85C
140
120
100
80
60
VSY = 15V
VCM = 0V
TA = 25C
500
QUANTITY – Amplifiers
QUANTITY – Amplifiers
160
40
20
15
10
5
600
200
180
VSY = 15V
VCM = 0V
TA = 40C TO +85C
25
NUMBER OF AMPLIFIERS
200
30
220
400
300
200
0
0
0.2
0.4
0.6
0.8
1.0
INPUT OFFSET DRIFT – V/C
1.2
TPC 3. OP777 Input Offset Voltage
Drift Distribution
600
VSY = 5V
VCM = 2.5V
TA = 25C
500
NUMBER OF AMPLIFIERS
VSY = 15V
VCM = 0V
TA = 25C
NUMBER OF AMPLIFIERS
220
400
300
200
100
100
20
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2
TCVOS – V/C
TPC 4. OP727/OP747 Input Offset
Voltage Drift (TCVOS Distribution)
300
200
80
120
TPC 7. OP727 Input Offset Voltage
Distribution
0
–120
120
–80
–40
0
40
80
120
OFFSET VOLTAGE – V
TPC 6. OP747 Input Offset Voltage
Distribution
30
400
300
200
100
100
0
140 120 80 40
0
40
80
OFFSET VOLTAGE – V
40
VSY = 15V
VCM = 0V
TA = 25C
500
NUMBER OF AMPLIFIERS
NUMBER OF AMPLIFIERS
0
V
600
VSY = 5V
VCM = 2.5V
TA = 25C
400
REV. C
–40
TPC 5. OP747 Input Offset Voltage
Distribution
600
500
–80
VSY = 15V
VCM = 0V
TA = 25C
25
NUMBER OF AMPLIFIERS
0
–120
0
20
15
10
5
0
0
40
140 120 80 40
80
OFFSET VOLTAGE – V
120
TPC 8. OP727 Input Offset Voltage
Distribution
–5–
0
3
5
7
4
6
INPUT BIAS CURRENT – nA
TPC 9. Input Bias Current
Distribution
8
OP777/OP727/OP747
VS = 5V
TA = 25C
1.0
0.1
100
10
SINK
1.0
SOURCE
0
0.001
100
0.1
1
10
LOAD CURRENT – mA
TPC 10. Output Voltage to Supply
Rail vs. Load Current
140
ISY+ (VSY = 5V)
100
0
100
200
ISY (VSY = 5V)
300
250
200
150
100
50
ISY (VSY = 15V)
400
100
OPEN-LOOP GAIN – dB
SUPPLY CURRENT – A
SUPPLY CURRENT – A
200
500
60 40 20 0 20 40 60 80 100 120 140
TEMPERATURE – C
0
TPC 13. Supply Current vs.
Temperature
0
5
10
15
20
25
SUPPLY VOLTAGE – V
60
VSY = 5V
CLOAD = 0
RLOAD =
80
0
60
45
40
90
20
135
0
180
–20
225
–40
270
1k
10k 100k
1M
FREQUENCY – Hz
10M
100M
TPC 16. Open Loop Gain and
Phase Shift vs. Frequency
CLOSED-LOOP GAIN – dB
100
0
45
40
90
20
135
0
180
–20
225
–40
270
–60
10
35
30
40
AV = 100
30
20
10
AV = 10
0
10
AV = +1
20
30
40
1k
100
1k
10k 100k
1M
10M 100M
FREQUENCY – Hz
TPC 15. Open Loop Gain and
Phase Shift vs. Frequency
60
VSY = 15V
CLOAD = 0
RLOAD = 2k
50
PHASE SHIFT – Degrees
120
80
60
TPC 14. Supply Current vs. Supply
Voltage
140
VSY = 15V
CLOAD = 0
RLOAD =
120
300
ISY+ (VSY = 15V)
2
TPC 12. Input Bias Current vs.
Temperature
TA = 25C
300
3
0
60 40 20 0 20 40 60 80 100 120 140
TEMPERATURE – C
100
350
400
OPEN-LOOP GAIN – dB
0.1
1
10
LOAD CURRENT – mA
0.01
TPC 11. Output Voltage to Supply
Rail vs. Load Current
500
4
1
0.1
0.01
5
PHASE SHIFT – Degrees
SOURCE
10
INPUT BIAS CURRENT – nA
SINK
100
–60
100
VSY = 15V
1k
OUTPUT VOLTAGE – mV
OUTPUT VOLTAGE – mV
1k
0
0.001
6
10k
VS = 15V
TA = 25C
VSY = 5V
CLOAD = 0
RLOAD = 2k
50
CLOSED-LOOP GAIN – dB
10k
40
AV = 100
30
20
10
AV = 10
0
10
AV = +1
20
30
10k
100k
1M
10M
FREQUENCY – Hz
100M
TPC 17. Closed Loop Gain vs.
Frequency
–6–
40
1k
10k
100k
1M
10M
FREQUENCY – Hz
100M
TPC 18. Closed Loop Gain vs.
Frequency
REV. C
OP777/OP727/OP747
240
210
180
150
120
90
60
AV = 100
AV = 10
240
210
AV = 1
180
150
120
90
60
30
0V
AV = 100 AV = 10
100k
10k
1M
FREQUENCY – Hz
10M
0
100
100M
TPC 21. Large Signal Transient
Response
VSY = 15V
CL = 300pF
RL = 2k
VIN = 100mV
AV = 1
20
OS
15
10
5
SMALL SIGNAL OVERSHOOT – %
OS
25
TIME – 10s/DIV
TPC 23. Small Signal Transient
Response
35
VSY = 2.5V
RL = 2k
VIN = 100mV
30
TIME – 100s/DIV
TIME – 10s/DIV
TPC 22. Large Signal Transient
Response
35
100M
AV = 1
TIME – 100s/DIV
40
10M
VSY = 2.5V
CL = 300pF
RL = 2k
VIN = 100mV
VOLTAGE – 50mV/DIV
0V
10k
1M
100k
FREQUENCY – Hz
TPC 20. Output Impedance vs.
Frequency
VSY = 15V
RL = 2k
CL = 300pF
AV = 1
1k
VOLTAGE – 50mV/DIV
1k
TPC 19. Output Impedance vs.
Frequency
VOLTAGE – 1V/DIV
AV = 1
30
0
100
SMALL SIGNAL OVERSHOOT – %
VSY = 2.5V
RL = 2k
CL = 300pF
VSY = 15V
270
AV = 1
OUTPUT IMPEDANCE – OUTPUT IMPEDANCE – 300
VSY = 5V
270
VOLTAGE – 1V/DIV
300
VSY = 15V
RL = 2k
VIN = 100mV
30
TPC 24. Small Signal Transient
Response
INPUT
+200mV
0V
25
VSY = 15V
RL = 10k
AV = 100
VIN = 200mV
+OS
20
OS
15
0V
10
10V
5
OUTPUT
0
1
100
10
CAPACITANCE – pF
1k
TPC 25. Small Signal Overshoot
vs. Load Capacitance
REV. C
0
1
10
100
1k
CAPACITANCE – pF
10k
TPC 26. Small Signal Overshoot
vs. Load Capacitance
–7–
TIME – 40s/DIV
TPC 27. Negative Overvoltage
Recovery
OP777/OP727/OP747
200mV
INPUT
INPUT
0V
INPUT
0V
0V
VSY = 15V
RL = 10k
AV = 100
VIN = 200mV
200mV
10V
VSY = 2.5V
RL = 10k
AV = 100
VIN = 200mV
0V
OUTPUT
2V
2V
0V
0V
OUTPUT
TIME – 40s/DIV
OUTPUT
TIME – 40s/DIV
TPC 29. Negative Overvoltage
Recovery
TPC 30. Positive Overvoltage
Recovery
140
140
VS = 15V
AV = 1
VOLTAGE – 5V/DIV
TIME – 40s/DIV
VSY = 2.5V
CMRR – dB
OUTPUT
120
100
100
80
60
80
60
40
40
20
20
0
TIME – 400s/DIV
TPC 31. No Phase Reversal
VSY = 15V
120
CMRR – dB
TPC 28. Positive Overvoltage
Recovery
INPUT
VSY = 2.5V
RL = 10k
AV = 100
VIN = 200mV
200mV
10
100
10k 100k
1k
FREQUENCY – Hz
1M
0
10M
TPC 32. CMRR vs. Frequency
140
10
100
10k 100k
1k
FREQUENCY – Hz
1M
10M
TPC 33. CMRR vs. Frequency
140
VSY = 2.5V
VSY = 5V
GAIN = 10M
VSY = 15V
120
120
+PSRR
80
60
+PSRR
80
PSRR
60
40
40
20
20
0
10
100
10k 100k
1k
FREQUENCY – Hz
1M
TPC 34. PSRR vs. Frequency
10M
VOLTAGE – 1V/DIV
100
PSRR
PSRR – dB
PSRR – dB
100
0
10
100
10k 100k
1k
FREQUENCY – Hz
1M
TPC 35. PSRR vs. Frequency
–8–
10M
TIME – 1s/DIV
TPC 36. 0.1 Hz to 10 Hz Input
Voltage Noise
REV. C
OP777/OP727/OP747
90
90
VSY = 15V
VSY = 2.5V
VOLTAGE NOISE DENSITY – nV/ Hz
VOLTAGE – 1V/DIV
VOLTAGE NOISE DENSITY – nV/ Hz
VSY = 15V
GAIN = 10M
80
70
60
50
40
30
20
80
70
60
50
40
30
20
10
0
200
300
FREQUENCY – Hz
400
40
40
30
25
20
15
10
5
35
30
25
20
15
10
5
500
1k
1.5k
FREQUENCY – Hz
2.0k
0
2.5k
TPC 40. Voltage Noise Density
50
20
ISC
10
0
10
20
30
40
ISC+
50
60 40 20 0 20 40 60 80 100 120 140
TEMPERATURE – C
TPC 43. Short Circuit Current vs.
Temperature
REV. C
500
VSY = 5V
40
30
20
ISC
10
0
10
20
ISC+
30
1k
1.5k
FREQUENCY – Hz
2.0k
2.5k
50
60 40 20 0 20 40 60 80 100 120 140
TEMPERATURE – C
TPC 42. Short Circuit Current vs.
Temperature
160
4.95
VSY = 5V
IL = 1mA
OUTPUT VOLTAGE HIGH – V
30
500
TPC 41. Voltage Noise Density
VSY = 15V
40
400
40
0
0
200
300
FREQUENCY – Hz
50
VSY = 2.5V
SHORT CIRCUIT CURRENT – mA
35
100
TPC 39. Voltage Noise Density
4.94
4.93
4.92
4.91
4.90
150
OUTPUT VOLTAGE LOW – mV
VSY = 15V
0
500
TPC 38. Voltage Noise Density
0
SHORT CIRCUIT CURRENT – mA
10
100
TPC 37. 0.1 Hz to 10 Hz Input
Voltage Noise
VOLTAGE NOISE DENSITY – nV/ Hz
VOLTAGE NOISE DENSITY – nV/ Hz
TIME – 1s/DIV
VSY = 5V
IL = 1mA
140
130
120
110
100
90
80
4.89
60 40 20 0 20 40 60 80 100 120 140
TEMPERATURE – C
TPC 44. Output Voltage High vs.
Temperature
–9–
70
60 40 20 0 20 40 60 80 100 120 140
TEMPERATURE – C
TPC 45. Output Voltage Low vs.
Temperature
OP777/OP727/OP747
14.960
14.958
14.956
14.954
14.952
14.950
14.948
14.935
1.5
VSY = 15V
IL = 1mA
VSY = 15V
VCM = 0V
TA = 25C
1.0
14.940
0.5
VOS – V
OUTPUT VOLTAGE HIGH – V
14.962
14.930
VSY = 15V
IL = 1mA
OUTPUT VOLTAGE LOW – V
14.964
14.945
0
14.950
0.5
14.955
1.0
14.960
60 40 20 0 20 40 60 80 100 120 140
TEMPERATURE – C
1.5
14.946
14.944
60 40 20 0 20 40 60 80 100 120 140
TEMPERATURE – C
TPC 46. Output Voltage High vs.
Temperature
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
TIME – Minutes
TPC 48. Warm-Up Drift
TPC 47. Output Voltage Low vs.
Temperature
The OP777/OP727/OP747 amplifier uses a precision Bipolar
PNP input stage coupled with a high-voltage CMOS output
stage. This enables this amplifier to feature an input voltage
range which includes the negative supply voltage (often groundin single-supply applications) and also swing to within 1 mV of the
output rails. Additionally, the input voltage range extends to within
1 V of the positive supply rail. The epitaxial PNP input structure
provides high breakdown voltage, high gain, and an input bias current figure comparable to that obtained with a “Darlington” input
stage amplifier but without the drawbacks (i.e., severe penalties for
input voltage range, offset, drift and noise). The PNP input structure
also greatly lowers the noise and reduces the dc input error terms.
Supply Voltage
VOLTAGE – 100V/DIV
BASIC OPERATION
VOUT
0V
VIN
TIME – 0.2ms/DIV
Figure 1. Input and Output Signals with VCM < 0 V
The amplifiers are fully specified with a single 5 V supply and, due
to design and process innovations, can also operate with a supply
voltage from 2.7 V up to 30 V. This allows operation from most
split supplies used in current industry practice, with the advantage
of substantially increased input and output voltage ranges over
conventional split-supply amplifiers. The OP777/OP727/OP747
series is specified with (VSY = 5 V, V– = 0 V and VCM = 2.5 V
which is most suitable for single-supply application. With PSRR of
130 dB (0.3 µV/V) and CMRR of 110 dB (3 µV/V) offset is minimally affected by power supply or common-mode voltages. Dual
supply, ±15 V operation is also fully specified.
100k
100k
+3V
0.27V
100k
100k
0.1V
OP777/
OP727/
OP747
VIN = 1kHz at 400mV p-p
Input Common-Mode Voltage Range
The OP777/OP727/OP747 is rated with an input common-mode
voltage which extends from the minus supply to within 1 V of the
positive supply. However, the amplifier can still operate with input
voltages slightly below VEE. In Figure 2, OP777/OP727/OP747 is
configured as a difference amplifier with a single supply of 2.7 V
and negative dc common-mode voltages applied at the inputs
terminals. A 400 mV p-p input is then applied to the noninverting
input. It can be seen from the graph below that the output does not
show any distortion. Micropower operation is maintained by using
large input and feedback resistors.
–10–
Figure 2. OP777/OP727/OP747 Configured as a Difference Amplifier Operating at VCM < 0 V
REV. C
OP777/OP727/OP747
Input Over Voltage Protection
30V
OP777/
OP727/
OP747
V p-p = 32V
VOUT
TIME – 400s/DIV
Figure 4. No Phase Reversal
Output Stage
The CMOS output stage has excellent (and fairly symmetric) output
drive and with light loads can actually swing to within 1 mV of both
supply rails. This is considerably better than similar amplifiers
featuring (so-called) rail-to-rail bipolar output stages. OP777/
OP727/OP747 is stable in the voltage follower configuration and
responds to signals as low as 1 mV above ground in single supply
operation.
2.7V TO 30V
Figure 3a. Unity Gain Follower
VOUT = 1mV
VSY = 15V
VOLTAGE – 5V/DIV
VIN
VSY = 15V
VIN
VOLTAGE – 5V/DIV
When the input of an amplifier is more than a diode drop below
VEE, or above V CC, large currents will flow from the substrate
(V–) or the positive supply (V+), respectively, to the input pins
which can destroy the device. In the case of OP777/OP727/
OP747, differential voltages equal to the supply voltage will not
cause any problem (see Figure 3). OP777/OP727/OP747 has
built- in 500 Ω internal current limiting resistors, in series with the
inputs, to minimize the chances of damage. It is a good practice to
keep the current flowing into the inputs below 5 mA. In this context it should also be noted that the high breakdown of the input
transistors removes the necessity for clamp diodes between the
inputs of the amplifier, a feature that is mandatory on many precision op amps. Unfortunately, such clamp diodes greatly interfere
with many application circuits such as precision rectifiers and
comparators. The OP777/OP727/OP747 series is free from such
limitations.
VIN = 1mV
VOUT
OP777/
OP727/
OP747
VOLTAGE – 25mV/DIV
Figure 5. Follower Circuit
TIME – 400s/DIV
Figure 3b. Input Voltage Can Exceed the Supply Voltage
Without Damage
1.0mV
Phase Reversal
Many amplifiers misbehave when one or both of the inputs are
forced beyond the input common-mode voltage range. Phase
reversal is typified by the transfer function of the amplifier effectively
reversing its transfer polarity. In some cases this can cause lockup in
servo systems and may cause permanent damage or nonrecoverable
parameter shifts to the amplifier. Many amplifiers feature compensation circuitry to combat these effects, but some are only effective for
the inverting input. Additionally, many of these schemes only work
for a few hundred millivolts or so beyond the supply rails. OP777/
OP727/OP747 has a protection circuit against phase reversal
when one or both inputs are forced beyond their input commonmode voltage range. It is not recommended that the parts be
continuously driven more than 3 V beyond the rails.
REV. C
TIME – 10s/DIV
Figure 6. Rail-to-Rail Operation
Output Short Circuit
The output of the OP777/OP727/OP747 series amplifier is protected
from damage against accidental shorts to either supply voltage,
provided that the maximum die temperature is not exceeded on a
long-term basis (see Absolute Maximum Rating section). Current of
up to 30 mA does not cause any damage.
A Low-Side Current Monitor
In the design of power supply control circuits, a great deal of design
effort is focused on ensuring a pass transistor’s long-term reliability
over a wide range of load current conditions. As a result, monitoring
–11–
OP777/OP727/OP747
and limiting device power dissipation is of prime importance in
these designs. Figure 7 shows an example of 5 V, single-supply
current monitor that can be incorporated into the design of a voltage
regulator with foldback current limiting or a high current power
supply with crowbar protection. The design capitalizes on the
OP777’s common-mode range that extends to ground. Current
is monitored in the power supply return where a 0.1 Ω shunt
resistor, RSENSE, creates a very small voltage drop. The voltage at the
inverting terminal becomes equal to the voltage at the noninverting
terminal through the feedback of Q1, which is a 2N2222 or equivalent NPN transistor. This makes the voltage drop across R1 equal to
the voltage drop across RSENSE. Therefore, the current through Q1
becomes directly proportional to the current through RSENSE, and
the output voltage is given by:
VOUT
15V
1k
REF
192
2N2222
1/4 OP747
R2
12k
4
3
20k
+15V
R1
R1
R(1+ )
R
+15V
VO
1/4 OP747
15V
R2
V
R1 REF
R
=
R
VO =
1/4 OP747
15V
Figure 9. Linear Response Bridge
 R2

= 5V − 
× RSENSE × I L 
 R1

The voltage drop across R2 increases with IL increasing, so VOUT
decreases with higher supply current being sensed. For the element
values shown, the VOUT is 2.5 V for return current of 1 A.
A single-supply current source is shown in Figure 10 . Large resistors
are used to maintain micropower operation. Output current can be
adjusted by changing the R2B resistor. Compliance voltage is:
VL ≤ VSAT − VS
10pF
2.7V TO 30V
5V
100k
R2 = 2.49k
100k
VOUT
OP777
R1 = 100k
Q1
R2B
2.7k
5V
10pF
OP777
R1 = 100
0.1
IO =
RETURN TO
GROUND
RSENSE
IO
R2 = R2A + R2B
R2
V
R1 R2B S
R2A
97.3k
+
VL
RLOAD
= 1mA 11mA
Figure 7. A Low-Side Load Current Monitor
Figure 10. Single-Supply Current Source
The OP777/OP727/OP747 is very useful in many bridge applications. Figure 8 shows a single-supply bridge circuit in which its
output is linearly proportional to the fractional deviation () of
the bridge. Note that = ∆R/R.
A single-supply instrumentation amplifier using one OP727
amplifier is shown in Figure 11. For true difference R3/R4 =
R1/R2. The formula for the CMRR of the circuit at dc is CMRR =
20 × log (100/(1–(R2 × R3)/(R1× R4)). It is common to specify t he
accuracy of the resistor network in terms of resistor-to-resistor
percentage mismatch. We can rewrite the CMRR equation to
reflect this CMRR = 20 × log (10000/% Mismatch). The key to
high CMRR is a network of resistors that are well matched from
the perspective of both resistive ratio and relative drift. It should
be noted that the absolute value of the resistors and their absolute
drift are of no consequence. Matching is the key. CMRR is 100 dB
with 0.1% mismatched resistor network. To maximize CMRR,
one of the resistors such as R4 should be trimmed. Tighter matching of two op amps in one package (OP727) offers a significant
boost in performance over the triple op amp configuration.
= 300
AR1 VREF
15V
VO =
2R2
R1
=
R1
RG = 10k
2
1/4 OP747
6
REF
192
2
1M
2.5V
4
REF
192
4
+ 2.5V
10.1k
3
1M
0.1F
15V
15V
3
R1
R1(1+ )
V1
10.1k
VO
1/4 OP747
R1(1+ )
1/4 OP747
R1
R3 = 10.1k
R2 = 1M
R2
2.7V TO 30V
V2
2.7V TO 30V
R4 = 1M
R1 = 10.1k
Figure 8. Linear Response Bridge, Single Supply
VO
1/2 OP727
In systems where dual supplies are available, the circuit of Figure
9 could be used to detect bridge outputs that are linearly related
to the fractional deviation of the bridge.
1/2 OP727
V1
V2
VO = 100 (V2 V1)
0.02mV V1 V2
2mV VOUT 29V
290mV
USE MATCHED RESISTORS
Figure 11. Single-Supply Micropower Instrumentation
Amplifier
–12–
REV. C
OP777/OP727/OP747
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
8-Lead MSOP
(RM-8)
0.122 (3.10)
0.114 (2.90)
8
5
0.122 (3.10)
0.114 (2.90)
0.199 (5.05)
0.187 (4.75)
1
4
PIN 1
0.0256 (0.65) BSC
0.120 (3.05)
0.112 (2.84)
0.120 (3.05)
0.112 (2.84)
0.043 (1.09)
0.037 (0.94)
0.006 (0.15)
0.002 (0.05)
0.018 (0.46)
SEATING 0.008 (0.20)
PLANE
0.011 (0.28)
0.003 (0.08)
33
27
0.028 (0.71)
0.016 (0.41)
8-Lead SOIC
(R-8)
0.1968 (5.00)
0.1890 (4.80)
0.1574 (4.00)
0.1497 (3.80)
8
5
1
4
0.2440 (6.20)
0.2284 (5.80)
PIN 1
0.0196 (0.50)
0.0099 (0.25)
0.0500 (1.27)
BSC
0.0688 (1.75)
0.0532 (1.35)
0.0098 (0.25)
0.0040 (0.10)
8
0.0500 (1.27)
0.0098 (0.25) 0
0.0160 (0.41)
0.0075 (0.19)
0.0192 (0.49)
0.0138 (0.35)
SEATING
PLANE
8-Lead TSSOP
(RU-8)
0.122 (3.10)
0.114 (2.90)
8
5
0.177 (4.50)
0.169 (4.30)
0.256 (6.50)
0.246 (6.25)
1
4
PIN 1
0.0256 (0.65)
BSC
0.006 (0.15)
0.002 (0.05)
SEATING
PLANE
REV. C
0.0118 (0.30)
0.0075 (0.19)
0.0433
(1.10)
MAX
0.0079 (0.20)
0.0035 (0.090)
–13–
8
0
0.028 (0.70)
0.020 (0.50)
45
OP777/OP727/OP747
14-Lead SOIC
(R-14)
0.3444 (8.75)
0.3367 (8.55)
0.1574 (4.00)
0.1497 (3.80)
14
8
1
7
0.050 (1.27)
BSC
0.0688 (1.75)
0.0532 (1.35)
PIN 1
0.0098 (0.25)
0.0040 (0.10)
0.2440 (6.20)
0.2284 (5.80)
0.0196 (0.50)
0.0099 (0.25)
45
8
0 0.0500 (1.27)
0.0192 (0.49) SEATING
0.0099 (0.25)
PLANE
0.0138 (0.35)
0.0160 (0.41)
0.0075 (0.19)
14-Lead TSSOP
(RU-14)
0.201 (5.10)
0.193 (4.90)
14
8
0.177 (4.50)
0.169 (4.30)
0.256 (6.50)
0.246 (6.25)
1
7
PIN 1
0.006 (0.15)
0.002 (0.05)
SEATING
PLANE
0.0256
(0.65)
BSC
0.0433 (1.10)
MAX
0.0118 (0.30)
0.0075 (0.19)
0.0079 (0.20)
0.0035 (0.090)
–14–
8
0
0.028 (0.70)
0.020 (0.50)
REV. C
OP777/OP727/OP747
Revision History
Location
Page
Data Sheet changed from REV. B to REV. C.
Addition of text to APPLICATIONS section
Addition of 8-Lead SOIC (R-8) package
...............................................................
1
..................................................................
1
Addition of text to GENERAL DESCRIPTION
Addition of package to ORDERING GUIDE
REV. C
.............................................................
1
...............................................................
2
–15–
–16–
PRINTED IN U.S.A.
CO2051–0–9/01(C)