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: 3.0 V to 30 V Dual-Supply Operation: 1.5 V to 15 V Low Supply Current: 300 A/Amp Max Unity Gain Stable No Phase Reversal
FUNCTIONAL BLOCK DIAGRAMS 8-Lead MSOP (RM-8) 1
NC IN IN V
8
NC V+ OUT NC
OP777 4
14-Lead SOIC (R-14)
5
NC = NO CONNECT
APPLICATIONS Current Sensing (Shunt) Line or Battery-Powered Instrumentation Remote Sensors Precision Filters OP727 SOIC Pin-Compatible with LT1013
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
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 3.0 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.
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)
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.
IN A 1 V– 2
OP727
8
–IN A
7
OUT A
TOP VIEW IN B 3 (Not to Scale) 6 V –IN B 4
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.
5
OUT B
NOTE: THIS PIN CONFIGURATION DIFFERS FROM THE STANDARD 8-LEAD OPERATIONAL AMPLIFIER PINOUT.
SIMILAR LOW POWER PRODUCTS Supply Voltage/ Supply Current Single Dual Quad
1.8 V/1 μA AD8500 AD8502 AD8504
1.8 V/20 μA ADA4051-1 ADA4051-2
1.8 V/25 μA AD8505 AD8506 AD8508
1.8 V/50 μA AD8603/AD8613 AD8607/AD8617 AD8609/AD8619
2.5 V/1 mA ADA4528-1
3.0 V/200 μA
4 V/215 μA
ADA4091-2 ADA4091-4
AD8622 AD8624
REV. D 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: 781/461-3113 © Analog Devices, Inc., 2011
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 ΔVOS/ΔT ΔVOS/ΔT
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. D
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 ΔVOS/ΔT ΔVOS/ΔT
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. D
–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.
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. D
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
180
140 120 100 80 60
VSY = 15V VCM = 0V TA = 25C
500
QUANTITY – Amplifiers
QUANTITY – Amplifiers
160
40
20
15
10
5
600
200
VSY = 15V VCM = 0V TA = 40C TO +85C
25
NUMBER OF AMPLIFIERS
200
30
220
400
300
200
0 0
1.2
0.2 0.4 0.6 0.8 1.0 INPUT OFFSET DRIFT – V/C
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. D
–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 FREQUENCY – Hz
10M 100M
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. D
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
10 100 CAPACITANCE – pF
1k
TPC 25. Small Signal Overshoot vs. Load Capacitance
REV. D
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. D
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
0
500
100
200 300 FREQUENCY – Hz
400
500
TPC 38. Voltage Noise Density
TPC 39. Voltage Noise Density
40
40
50
25 20 15 10 5
35
SHORT CIRCUIT CURRENT – mA
30
VSY = 2.5V
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. D
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
30 20
40
0
0
VSY = 5V
40
4.94
4.93
4.92
4.91
4.90
150
OUTPUT VOLTAGE LOW – mV
VSY = 15V
35
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 – 100mV/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 3.0 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 3.0 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. D
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. 3.0 V 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. D
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 3.0 V 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 = ΔR/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 AR1VREF
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 3.0 V TO 30V
V2
3.0 V 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
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REV. D
OP777/OP727/OP747 OUTLINE DIMENSIONS 3.20 3.00 2.80
8
3.20 3.00 2.80
5.15 4.90 4.65
5
1
4
PIN 1 IDENTIFIER 0.65 BSC 0.95 0.85 0.75
15° MAX 1.10 MAX
6° 0°
0.40 0.25
0.80 0.55 0.40
0.23 0.09
10-07-2009-B
0.15 0.05 COPLANARITY 0.10
COMPLIANT TO JEDEC STANDARDS MO-187-AA
Figure 12. 8-Lead Mini Small Outline Package [MSOP] (RM-8) Dimensions shown in millimeters
5.00 (0.1968) 4.80 (0.1890)
1
5 4
1.27 (0.0500) BSC 0.25 (0.0098) 0.10 (0.0040) COPLANARITY 0.10 SEATING PLANE
6.20 (0.2441) 5.80 (0.2284)
1.75 (0.0688) 1.35 (0.0532)
0.51 (0.0201) 0.31 (0.0122)
0.50 (0.0196) 0.25 (0.0099) 8° 0° 0.25 (0.0098) 0.17 (0.0067)
1.27 (0.0500) 0.40 (0.0157)
COMPLIANT TO JEDEC STANDARDS MS-012-AA CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.
Figure 13. 8-Lead Standard Small Outline Package [SOIC_N] Narrow Body (R-8) Dimensions shown in millimeters and (inches)
REV. D
–13–
45°
012407-A
8
4.00 (0.1574) 3.80 (0.1497)
OP777/OP727/OP747 3.10 3.00 2.90
8
5
4.50 4.40 4.30 1
6.40 BSC
4
PIN 1 0.65 BSC 0.15 0.05
1.20 MAX
COPLANARITY 0.10
0.30 0.19
SEATING 0.20 PLANE 0.09
8° 0°
0.75 0.60 0.45
COMPLIANT TO JEDEC STANDARDS MO-153-AA
Figure 14. 8-Lead Thin Shrink Small Outline Package [TSSOP] (RU-8) Dimensions shown in millimeters
8.75 (0.3445) 8.55 (0.3366) 8
14 1
7
1.27 (0.0500) BSC 0.25 (0.0098) 0.10 (0.0039) COPLANARITY 0.10
0.51 (0.0201) 0.31 (0.0122)
6.20 (0.2441) 5.80 (0.2283)
1.75 (0.0689) 1.35 (0.0531) SEATING PLANE
0.50 (0.0197) 0.25 (0.0098)
45°
8° 0° 0.25 (0.0098) 0.17 (0.0067)
1.27 (0.0500) 0.40 (0.0157)
COMPLIANT TO JEDEC STANDARDS MS-012-AB CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.
060606-A
4.00 (0.1575) 3.80 (0.1496)
Figure 15. 14-Lead Standard Small Outline Package [SOIC_N] Narrow Body (R-14) Dimensions shown in millimeters and (inches)
–14–
REV. D
OP777/OP727/OP747 5.10 5.00 4.90
14
8
4.50 4.40 4.30
6.40 BSC 1
7
PIN 1 0.65 BSC
0.15 0.05 COPLANARITY 0.10
1.20 MAX
0.30 0.19
0.20 0.09
SEATING PLANE
8° 0°
COMPLIANT TO JEDEC STANDARDS MO-153-AB-1
0.75 0.60 0.45 061908-A
1.05 1.00 0.80
Figure 16. 14-Lead Thin Shrink Small Outline Package [TSSOP] (RU-14) Dimensions shown in millimeters
ORDERING GUIDE Model1 OP727AR OP727AR-REEL OP727AR-REEL7 OP727ARUZ OP727ARUZ-REEL OP727ARZ OP727ARZ-REEL OP727ARZ-REEL7 OP747ARU OP747ARU-REEL OP747ARUZ OP747ARUZ-REEL OP747ARZ OP747ARZ-REEL OP747ARZ-REEL7 OP777ARMZ OP777ARMZ-REEL OP777ARZ OP777ARZ-REEL OP777ARZ-REEL7 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 –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
Package Description 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead TSSOP 8-Lead TSSOP 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 14-Lead TSSOP 14-Lead TSSOP 14-Lead TSSOP 14-Lead TSSOP 14-Lead SOIC 14-Lead SOIC 14-Lead SOIC 8-Lead MSOP 8-Lead MSOP 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N
Z = RoHS Compliant Part.
REV. D
–15–
Package Option R-8 R-8 R-8 RU-8 RU-8 R-8 R-8 R-8 RU-14 RU-14 RU-14 RU-14 R-14 R-14 R-14 RM-8 RM-8 R-8 R-8 R-8
Branding
A1A A1A
OP777/OP727/OP747 REVISION HISTORY 10/11—Rev. C to Rev. D Changed Single Supply Operation from 2.7 V to 30 V to 3.0 V to 30 V ...................................................................................... 1 Changed Dual Supply Operation from ±1.35 V to ±15 V to ±1.5 V to ±15 V................................................................................. 1 Changes to General Description Section ...................................... 1 Added Similar Low Power Products Table .................................... 1 Changes to Supply Voltage Section, Input Common-Mode Voltage Range Section, and Figure 1 ............................................ 10 Changes to Figure 5 ........................................................................ 11 Changes to Figure 10 and Figure 11 ............................................. 12 Updated Outline Dimensions ....................................................... 13 Changes to Ordering Guide .......................................................... 15 9/01—Rev. B to Rev. C Addition of text to Applications Section ....................................... 1 Addition of 8-Lead SOIC (R-8) Package ....................................... 1 Addition of text to General Description........................................ 1 Addition of package to Ordering Guide ........................................ 2
©2011 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D02051-0-10/11(D)
–16–
REV. D