Datasheet OP27AZ, OP27FP, OP27GP, OP27EJ, OP27EP Datasheet (Analog Devices)

...
Page 1
Low-Noise, Precision
a

FEATURES

Low Noise: 80 nV p-p (0.1 Hz to 10 Hz), 3 nV/ Low Drift: 0.2 V/C High Speed: 2.8 V/s Slew Rate, 8 MHz Gain
Bandwidth Low V Excellent CMRR: 126 dB at V
: 10 V
OS
of ±11 V
CM
High Open-Loop Gain: 1.8 Million Fits 725, OP07, 5534A Sockets Available in Die Form
GENERAL DESCRIPTION
The OP27 precision operational amplifier combines the low offset and drift of the OP07 with both high speed and low noise. Offsets down to 25 µV and drift of 0.6 µV/°C maximum make the OP27 ideal for precision instrumentation applications. Exceptionally low noise, e
= 3.5 nV/Hz, at 10 Hz, a low 1/f
n
noise corner frequency of 2.7 Hz, and high gain (1.8 million), allow accurate high-gain amplification of low-level signals. A gain-bandwidth product of 8 MHz and a 2.8 V/µsec slew rate provides excellent dynamic accuracy in high-speed, data­acquisition systems.
A low input bias current of ±10 nA is achieved by use of a bias-current-cancellation circuit. Over the military temperature range, this circuit typically holds I
and IOS to ±20 nA and 15 nA,
B
respectively.
The output stage has good load driving capability. A guaranteed swing of ±10 V into 600 and low output distortion make the OP27 an excellent choice for professional audio applications.
Hz
(Continued on page 7)
Operational Amplifier
OP27
PIN CONNECTIONS
TO-99
(J-Suffix)
BAL
BAL 1
–IN 2
+IN 3
OP27
4V– (CASE)
NC = NO CONNECT
8-Pin Hermetic DIP
(Z-Suffix)
Epoxy Mini-DIP
(P-Suffix)
8-Pin SO
(S-Suffix)
TRIM
OS
–IN
+IN
1
OP27
2
3
4
NC = NO CONNECT
V
V+
OUT
NC
8
V
TRIM
OS
7
V+
6
OUT
5
NCV–
NONINVERTING
INPUT (+)
INVERTING
INPUT (–)
R1 AND R2 ARE PERMANENTLY
*
ADJUSTED AT WAFER TEST FOR MINIMUM OFFSET VOLTAGE.
Q6
Q3
R1*
R3
18
V
ADJ.
OS
Q2B
R4
R2*
Q2AQ1A Q1B
Q11 Q12
Figure 1. Simplified Schematic
REV. A
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.
V+
C2
Q22
Q21
R23 R24
Q23
Q27 Q28
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781/329-4700 www.analog.com Fax: 781/326-8703 © Analog Devices, Inc., 2002
Q24
R5
C1
R9
R12
C3 C4
Q20 Q19
Q26
Q46
OUTPUT
Q45
V–
Page 2
OP27
–SPECIFICATIONS
ELECTRICAL CHARACTERISTICS
(@ VS = ±15 V, TA = 25C, unless otherwise noted.)
OP27A/E OP27F OP27C/G
Parameter Symbol Conditions Min Typ Max Min Typ Max Min Typ Max Unit
INPUT OFFSET VOLTAGE
LONG-TERM V
STABILITY
1
OS
2, 3
V
OS
10 25 20 60 30 100 µV
VOS/Time 0.2 1.0 0.3 1.5 0.4 2.0 µV/M
INPUT OFFSET CURRENT I
OS
7 35 9 50 12 75 nA
INPUT BIAS CURRENT I
INPUT NOISE
VOLTAGE
INPUT NOISE e
Voltage Density
3, 4
3
e
B
n p-p
n
0.1 Hz to 10 Hz 0.08 0.18 0.08 0.18 0.09 0.25 µV p-p
fO = 10 Hz 3.5 5.5 3.5 5.5 3.8 8.0 nV/Hz fO = 30 Hz 3.1 4.5 3.1 4.5 3.3 5.6 nV/Hz
±10 ±40 ±12 ±55 ±15 ±80 nA
fO = 1000 Hz 3.0 3.8 3.0 3.8 3.2 4.5 nV/Hz
INPUT NOISE i
Current Density
3, 5
n
fO = 10 Hz 1.7 4.0 1.7 4.0 1.7 pA/Hz fO = 30 Hz 1.0 2.3 1.0 2.3 1.0 pA/Hz fO = 1000 Hz 0.4 0.6 0.4 0.6 0.4 0.6 pA/Hz
INPUT RESISTANCE
Differential-Mode Common-Mode R
6
R
IN
INCM
1.3 6 0.94 5 0.7 4 M 3 2.5 2 G
INPUT VOLTAGE RANGE IVR ±11.0 ±12.3 ±11.0 ±12.3 ±11.0 ±12.3 V
COMMON-MODE
REJECTION RATIO CMRR VCM = ±11 V 114 126 106 123 100 120 dB
POWER SUPPLY PSRR VS = ±4 V
REJECTION RATIO to ±18 V 1 10 1 10 2 20 µV/V
LARGE-SIGNAL A
VO
VOLTAGE GAIN V
RL 2 k,
= ±10 V 1000 1800 1000 1800 700 1500 V/mV
O
600 ,
R
L
VO = ±10 V 800 1500 800 1500 600 1500 V/mV
OUTPUT VOLTAGE SWING V
O
RL ≥ 2 kΩ±12.0 ± 13.8 ± 12.0 ± 13.8 ±11.5 ± 13.5 V RL ≥ 600 Ω±10.0 ± 11.5 ± 10.0 ± 11.5 ±10.0 ± 11.5 V
SLEW RATE
7
SR RL 2 k 1.7 2.8 1.7 2.8 1.7 2.8 V/µs
O
GAIN BANDWIDTH
PRODUCT
7
GBW 5.0 8.0 5.0 8.0 5.0 8.0 MHz
OPEN-LOOP OUTPUT
RESISTANCE R
O
VO = 0, IO = 07070 70
POWER CONSUMPTION P
d
V
O
90 140 90 140 100 170 mW
OFFSET ADJUSTMENT
RANGE RP = 10 kΩ±4.0 ±4.0 ± 4.0 mV
NOTES
1
Input offset voltage measurements are performed ~ 0.5 seconds after application of power. A/E grades guaranteed fully warmed up.
2
Long-term input offset voltage stability refers to the average trend line of VOS versus. Time over extended periods after the first 30 days of operation. Excluding the initial hour of operation, changes in VOS during the first 30 days are typically 2.5 µV. Refer to typical performance curve.
3
Sample tested.
4
See test circuit and frequency response curve for 0.1 Hz to 10 Hz tester.
5
See test circuit for current noise measurement.
6
Guaranteed by input bias current.
7
Guaranteed by design.
–2–
REV. A
Page 3
OP27
ELECTRICAL CHARACTERISTICS
(@ VS = ±15 V, –55C TA 125C, unless otherwise noted.)
OP27A OP27C
Parameter Symbol Conditions Min Typ Max Min Typ Max Unit
INPUT OFFSET VOLTAGE
AVERAGE INPUT OFFSET DRIFT TCV
1
V
OS
TCV
OS
OSn
30 60 70 300 µV
2
3
0.2 0.6 4 1.8 µV/°C
INPUT OFFSET CURRENT I
OS
15 50 30 135 nA
INPUT BIAS CURRENT I
B
±20 ±60 ±35 ±150 nA
INPUT VOLTAGE RANGE IVR ±10.3 ± 11.5 ±10.2 ± 11.5 V
COMMON-MODE
REJECTION RATIO CMRR VCM = ±10 V 108 122 94 118 dB
POWER SUPPLY
REJECTION RATIO PSRR VS = ±4.5 V to ±18 V 2 16 4 51 µV/V
LARGE-SIGNAL VOLTAGE GAIN A
VO
RL 2 k, VO = ±10 V 600 1200 300 800 V/mV
OUTPUT VOLTAGE SWING V
NOTES
1
Input offset voltage measurements are performed by automated test equipment approximately 0.5 seconds after application of power. A/E grades guaranteed fully warmed up.
2
The TCVOS performance is within the specifications unnulled or when nulled with RP = 8 k to 20 k. TCVOS is 100% tested for A/E grades, sample tested for C/F/G grades.
3
Guaranteed by design.
O
RL 2 kΩ±11.5 ± 13.5 ±10.5 ±13.0 V
REV. A
–3–
Page 4
OP27
(@ VS = ±15 V, –25 TA 85C for OP27J, OP27Z, 0C TA 70C for OP27EP,
ELECTRICAL CHARACTERISTICS
Parameter Symbol Conditions Min Typ Max Min Typ Max Min Typ Max Unit
INPUT ONSET VOLTAGE V
AVERAGE INPUT OFFSET DRIFT TCV
INPUT OFFSET CURRENT I
INPUT BIAS CURRENT I
INPUT VOLTAGE RANGE IVR ±10.5 ±11.8 ±10.5 ±11.8 ±10.5 ±11.8 V
COMMON-MODE
REJECTION RATIO CMRR VCM = ±10 V 110 124 102 121 96 118 dB
POWER SUPPLY
REJECTION RATIO PSRR VS = ±4.5 V 2 15 2 16 2 32 µV/V
LARGE-SIGNAL
VOLTAGE GAIN A
OUTPUT VOLTAGE SWING V
NOTES
1
The TCVOS performance is within the specifications unnulled or when nulled with RP = 8 k to 20 k. TCVOS is 100% tested for A/E grades, sample tested for C/F/G grades.
2
Guaranteed by design.
OS
TCV
OS
B
VO
O
1
OS
2
OSn
to ±18 V
R
2 k,
L
VO = ±10 V 750 1500 700 1300 450 1000 V/mV
RL 2 kΩ±11.7 ±13.6 ±11.4 ±13.5 ± 11.0 ± 13.3 V
OP27FP, and –40C TA 85C for OP27GP, OP27GS, unless otherwise noted.)
OP27E OP27F OP27G
20 50 40 140 55 220 µV
0.2 0.6 0.3 1.3 0 4 1.8 µV/°C
0.2 0.6 0.3 1.3 0 4 1.8 µV/°C
10 50 14 85 20 135 nA
±14 ±60 ±18 ±95 ±25 ± 150 nA
–4–
REV. A
Page 5

DICE CHARACTERISTICS

DIE SIZE 0.109  0.055 INCH, 5995 SQ. MILS
(2.77 1.40mm, 3.88 SQ. mm)
1. NULL
2. (–) INPUT
3. (+) INPUT
4. V–
6. OUTPUT
7. V+
8. NULL
OP27
WAFER TEST LIMITS
(@ VS = ±15 V, TA = 25C unless otherwise noted.)
OP27N OP27G OP27GR
Parameter Symbol Conditions Limit Limit Limit Unit
INPUT OFFSET VOLTAGE* V
INPUT OFFSET CURRENT I
OS
OS
35 60 100 µV Max
35 50 75 nA Max
INPUT BIAS CURRENT IB ±40 ±55 ± 80 nA Max INPUT VOLTAGE RANGE IVR ±11 ±11 ± 11 V Min
COMMON-MODE REJECTION RATIO CMRR V
= IVR 114 106 100 dB Min
CM
POWER SUPPLY PSRR VS = ±4 V to ±18 V 10 10 20 µV/V Max
LARGE-SIGNAL VOLTAGE GAIN A
OUTPUT VOLTAGE SWING V
POWER CONSUMPTION P
NOTE *Electrical tests are performed at wafer probe to the limits shown. Due to variations in assembly methods and normal yield loss, yield after packaging is not guaranteed
for standard product dice. Consult factory to negotiate specifications based on dice lot qualification through sample lot assembly and testing.
VO
A
VO
O
V
O
d
RL ≥ 2 kΩ, VO = ±10 V 1000 1000 700 V/mV Min RL ≥ 600 Ω, VO = ±10 V 800 800 600 V/mV Min
RL ≥ 2 kΩ±12.0 ± 12.0 +11.5 V Min RL2600n ±10.0 ±10.0 ± 10.0 V Min
VO = 0 140 140 170 mW Max
REV. A
–5–
Page 6
OP27
TYPICAL ELECTRICAL CHARACTERISTICS
(@ VS = ±15 V, TA = 25C unless otherwise noted.)
OP27N OP27G OP27GR
Parameter Symbol Conditions Typical Typical Typical Unit
AVERAGE INPUT OFFSET VOLTAGE DRIFT* TCVOS or Nulled or Unnulled 0.2 0.3 0.4 µV/°C
TCV
OSn
RP = 8 k to 20 k
AVERAGE INPUT OFFSET CURRENT DRIFT TCI
OS
80 130 180 pA/°C
AVERAGE INPUT BIAS CURRENT DRIFT TCI
B
100 160 200 pA/°C
INPUT NOISE VOLTAGE DENSITY e
n
e
n
e
n
fO = 10 Hz 3.5 3.5 3.8 nV/Hz fO = 30 Hz 3.1 3.1 3.3 nV/Hz fO = 1000 Hz 3.0 3.0 3.2 nV/Hz
INPUT NOISE CURRENT DENSITY i
INPUT NOISE VOLTAGE e
i i
n
n
n
np-p
SLEW RATE SR R
fO = 10 Hz 1.7 1.7 1.7 pA/Hz fO = 30 Hz 1.0 1.0 1.0 pA/Hz fO = 1000 Hz 0.4 0.4 0.4 pA/Hz
0.1 Hz to 10 Hz 0.08 0.08 0.09 µV p-p 2 k 2.8 2.8 2.8 V/µs
L
GAIN BANDWIDTH PRODUCT GBW 8 8 8 MHz
NOTE
*Input offset voltage measurements are performed by automated test equipment approximately 0.5 seconds after application of power.
–6–
REV. A
Page 7
OP27
WARNING!
ESD SENSITIVE DEVICE
(Continued from page 1)
PSRR and CMRR exceed 120 dB. These characteristics, coupled with long-term drift of 0.2 µV/month, allow the circuit designer to achieve performance levels previously attained only by dis­crete designs.
Low-cost, high-volume production of OP27 is achieved by using an on-chip Zener zap-trimming network. This reliable and stable offset trimming scheme has proved its effectiveness over many years of production history.

ABSOLUTE MAXIMUM RATINGS

Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±22 V
Input Voltage
Output Short-Circuit Duration . . . . . . . . . . . . . . . . Indefinite
Differential Input Voltage Differential Input Current
1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±22 V
2
. . . . . . . . . . . . . . . . . . . . . . ±0.7 V
2
. . . . . . . . . . . . . . . . . . . . ±25 mA
4
Storage Temperature Range . . . . . . . . . . . . –65°C to +150°C
Operating Temperature Range
OP27A, OP27C (J, Z) . . . . . . . . . . . . . . . . –55°C to +125°C
OP27E, OP27F (J, Z) . . . . . . . . . . . . . . . . . –25°C to +85°C
OP27E, OP27F (P) . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C
OP27G (P, S, J, Z) . . . . . . . . . . . . . . . . . . –40°C to +85°C
Lead Temperature Range (Soldering, 60 sec) . . . . . . . 300°C
Junction Temperature . . . . . . . . . . . . . . . . . –65°C to +150°C
The OP27 provides excellent performance in low-noise, high­accuracy amplification of low-level signals. Applications include stable integrators, precision summing amplifiers, precision voltage­threshold detectors, comparators, and professional audio circuits such as tape-head and microphone preamplifiers.
The OP27 is a direct replacement for 725, OP06, OP07, and OP45 amplifiers; 741 types may be directly replaced by remov­ing the 741’s nulling potentiometer.
Package Type
3
JA
JC
Unit
TO 99 (J) 150 18 °C/W 8-Lead Hermetic DlP (Z) 148 16 °C/W 8-Lead Plastic DIP (P) 103 43 °C/W 20-Contact LCC (RC) 98 38 °C/W 8-Lead SO (S) 158 43 °C/W
NOTES
1
For supply voltages less than ± 22 V, the absolute maximum input voltage is equal to the supply voltage.
2
The OP27’s inputs are protected by back-to-back diodes. Current limiting resistors are not used in order to achieve low noise. If differential input voltage exceeds ± 0.7 V, the input current should be limited to 25 mA.
3
is specified for worst-case mounting conditions, i.e., JA is specified for
JA
device in socket for TO, CERDIP, and P-DIP packages; JA is specified for device soldered to printed circuit board for SO package.
4
Absolute Maximum Ratings apply to both DICE and packaged parts, unless otherwise noted.
ORDERING INFORMATION
1
Package
= 25°C Operating
T
A
V
Max CERDIP Plastic Temperature
OS
(µV) TO-99 8-Lead 8-Lead Range
25 OP27AJ 25 OP27EJ
2, 3
2, 3
OP27AZ
OP27EZ OP27EP IND/COM 60 OP27FP 100 OP27CZ 100 OP27GJ OP27GZ OP27GP XIND 100 OP27GS
NOTES
1
Burn-in is available on commercial and industrial temperature range parts in CERDIP, plastic DIP, and TO-can packages.
2
For devices processed in total compliance to MIL-STD-883, add /883 after part number. Consult factory for 883 data sheet.
3
Not for new design; obsolete April 2002.
4
For availability and burn-in information on SO and PLCC packages, contact your local sales office.
2
3
3
4
MIL
IND/COM MIL
XIND
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 OP27 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.
REV. A
–7–
Page 8
OP27
–Typical Performance Characteristics
100
90
80
70
60
GAIN – dB
50
TEST TIME OF 10sec FURTHER LIMITS LOW FREQUENCY
40
(<0.1Hz) GAIN
30
0.01
TPC 1. 0.1 Hz to 10 Hz
0.1 1 10 100 FREQUENCY – Hz
Noise Tester
p-p
Frequency Response
10
TA = 25C
= 15V
V
S
1
0.1
RMS VOLTAGE NOISE – V
0.01 100 1k 10k
BANDWIDTH – Hz
TPC 4. Input Wideband Voltage Noise vs. Bandwidth (0.1 Hz to Frequency Indicated)
100k
10
9 8
7 6
5
4
3
I/F CORNER = 2.7Hz
2
VOLTAGE NOISE – nV/ Hz
1
1
10 100 1k
FREQUENCY – Hz
TA = 25C
= 15V
V
S
TPC 2. Voltage Noise Density vs. Frequency
100
10
TOTAL NOISE – nV/ Hz
1
TA = 25C
= 15V
V
S
AT 10Hz
AT 1kHz
RESISTOR NOISE ONLY
SOURCE RESISTANCE –
R
R1
R2
S
– 2R1
TPC 5. Total Noise vs. Sourced Resistance
100
741
10
VOLTAGE NOISE – nV/ Hz
1
1
I/F CORNER =
2.7Hz
INSTRUMENTATION
I/F CORNER
LOW NOISE
OP27
I/F CORNER
RANGE TO DC
10 100 1k
FREQUENCY – Hz
AUDIO OP AMP
AUDIO RANGE
TO 20kHz
TPC 3. A Comparison of Op Amp Voltage Noise Spectra
5
4
3
2
VOLTAGE NOISE – nV/ Hz
1
10k100 1k
–50 –25 0 25 50 75 100 125
AT 10Hz
AT 1kHz
TEMPERATURE – C
VS = 15V
TPC 6. Voltage Noise Density vs. Temperature
5
T
= 25C
A
4
3
2
VOLTAGE NOISE – nV/ Hz
1
010 40
TOTAL SUPPLY VOLTAGE (V+ – V–) – V
AT 10Hz
AT 1kHz
20 30
TPC 7. Voltage Noise Density vs. Supply Voltage
10.0
1.0
CURRENT NOISE – pA/ Hz
0.1
I/F CORNER = 140Hz
10 10k
100 1k FREQUENCY – Hz
TPC 8. Current Noise Density vs. Frequency
–8–
5.0
4.0
TA = +125C
3.0
TA = –55C
2.0
SUPPLY CURRENT – mA
1.0
TA = +25C
15 25 35 45
5
TOTAL SUPPLY VOLTAGE – V
TPC 9. Supply Current vs. Supply Voltage
REV. A
Page 9
OP27
60
50
40
30 20
10
0
10
20
30
OFFSET VOLTAGE V
40
TRIMMING WITH 10k POT DOES
–50
NOT CHANGE
–60
TCV
OS
70
75
50 25 0 25 50 75 100 125 150 175
TEMPERATURE – C
OP27C
OP27A
OP27A
OP27A
OP27C
TPC 10. Offset Voltage Drift of Five Representative Units vs. Temperature
OPEN-LOOP GAIN – dB
30
25
TA =
25C
20
15
10
5
0
–20
= 70C
T
A
THERMAL SHOCK RESPONSE BAND
DEVICE IMMERSED IN 70C OIL BATH
02040
TIME – Sec
VS = 15V
60 80
100
TPC 13. Offset Voltage Change Due to Thermal Shock
6
4
2
0
2
4
6
6
4
2
0
–2
CHANGE IN OFFSET VOLTAGE – V
4
6
0
1234567
TIME – Months
TPC 11. Long-Term Offset Voltage Drift of Six Representative Units
INPUT BIAS CURRENT – nA
50
40
30
20
10
0
50
25 0 25 50 75 100 125 150
OP27C
OP27A
TEMPERATURE – C
VS = 15V
TPC 14. Input Bias Current vs. Temperature
TA = 25C
= 15V
V
S
10
OP27 C/G
OP27 F
5
CHANGE IN INPUT OFFSET VOLTAGE – V
1
01 4
TIME AFTER POWER ON – Min
23
OP27 A/E
TPC 12. Warm-Up Offset Voltage Drift
50
40
30
20
OP27C
10
INPUT OFFSET CURRENT – nA
0
75
50 25 0 25 50 75 100 125
OP27A
TEMPERATURE – C
VS = 15V
TPC 15. Input Offset Current vs. Temperature
5
130
110
90
70
50
VOLTAGE GAIN – dB
30
10
–10
1
10 100 1k 10k 100k 1M 10M 100M
FREQUENCY – Hz
TPC 16. Open-Loop Gain vs. Frequency
REV. A
70
60
50
PHASE MARGIN – Degrees
4
3
2
SLEW RATE – V/s
–75
M
GBW
SLEW
50
25 0 25 50 75 100 125
TEMPERATURE – C
VS = 15V
10
9
8
7
6
TPC 17. Slew Rate, Gain-Bandwidth Product, Phase Margin vs. Temperature
–9–
25
GAIN
PHASE
MARGIN
= 70
FREQUENCY – Hz
GAIN BANDWIDTH PRODUCT – MHz
20
15
10
5
GAIN – dB
0
5
10
1M 10M 100M
TPC 18. Gain, Phase Shift vs. Frequency
TA = 25C
= 15V
V
S
80
100
120
140
160
180
200
220
PHASE SHIFT – Degrees
Page 10
OP27
2.5 TA = 25C
2.0
RL = 2k
1.5
RL = 1k
1.0
OPEN-LOOP GAIN – V/V
0.5
0
010 40
20 30
TOTAL SUPPLY VOLTAGE – V
50
TPC 19. Open-Loop Voltage Gain vs. Supply Voltage
100
% OVERSHOOT
80
60
40
20
V
S
V
IN
A
V
= 15V
= +1
= 100mV
28
24
20
16
12
8
PEAK-TO-PEAK AMPLITUDE – V
4
0
1k 10k 100k 1M
FREQUENCY – Hz
T
= 25C
A
= 15V
V
S
10M
TPC 20. Maximum Output Swing vs. Frequency
20mV
50mV
0V
500ns
A
VCL
= 15pF
C
L
= 15V
V
S
= 25C
T
A
= +1
–50mV
18
16
POSITIVE
14
12
10
8
6
4
MAXIMUM OUTPUT – V
2
0
–2
100
SWING
NEGATIVE SWING
LOAD RESISTANCE –
1k 10k
TA = 25C
= 15V
V
S
TPC 21. Maximum Output Voltage vs. Load Resistance
2V
+5V
0V
–5V
2s
A
VCL
= 15V
V
S
= 25C
T
A
= +1
0
0 500 2000
1000 1500
CAPACITIVE LOAD – pF
2500
TPC 22. Small-Signal Overshoot vs. Capacitive Load
60
TA = 25C
= 15V
V
S
50
40
30
20
SHORT-CIRCUIT CURRENT – mA
10
01 4
TIME FROM OUTPUT SHORTED TO
I
(+)
SC
I
(–)
SC
23 5
GROUND – Min
TPC 25. Short-Circuit Current vs. Time
TPC 23. Small-Signal Transient Response
140
120
100
CMRR – dB
80
60
1k
FREQUENCY – Hz
VS = 15V T
A
V
CM
10k 100k 1M100
TPC 26. CMRR vs. Frequency
= 25C
= 10V
TPC 24. Large-Signal Transient Response
16
12
8
4
0
4
8
COMMON-MODE RANGE V
12
16
0 5
TA = +25C
TA = –55C
TA = +125C
TA = –55C
TA = +25C
TA = +125C
10 15 20
SUPPLY VOLTAGE – V
TPC 27. Common-Mode Input Range vs. Supply Voltage
–10–
REV. A
Page 11
OP27
0.1F
100k
OP27
10
D.U.T.
VO LTAG E
GAIN
= 50,000
4.7F
2k
OP12
100k
24.3k
0.1F
4.3k
2.2F
22F
SCOPE  1 RIN = 1M
110k
TPC 28. Voltage Noise Test Circuit (0.1 Hz to 10 Hz)
2.4 TA = 25C
2.2
= 15V
V
S
2.0
1.8
1.6
1.4
1.2
1.0
0.8
OPEN-LOOP VOLTAGE GAIN – V/V
0.6
0.4
100 1k 10k 100k
LOAD RESISTANCE –
TPC 29. Open-Loop Voltage Gain vs. Load Resistance
POWER SUPPLY REJECTION RATIO – dB
160
140
120
100
80
60
40
20
0
1
10 100 1k 10k 100k 1M 10M 100M
NEGATIVE SWING
POSITIVE
SWING
FREQUENCY – Hz
TA = 25C
TPC 31. PSRR vs. Frequency
1 SEC/DIV
80
40
0
0.1Hz to 10Hz p-p NOISE
VOLTAGE NOISE – nV
120
40
90
120
TPC 30. Low-Frequency Noise

APPLICATION INFORMATION

OP27 series units may be inserted directly into 725 and OP07 sockets with or without removal of external compensation or nulling components. Additionally, the OP27 may be fitted to unnulled 741-type sockets; however, if conventional 741 nulling circuitry is in use, it should be modified or removed to ensure correct OP27 operation. OP27 offset voltage may be nulled to zero (or another desired setting) using a potentiometer (see Offset Nulling Circuit).
The OP27 provides stable operation with load capacitances of up to 2000 pF and ±10 V swings; larger capacitances should be decoupled with a 50 resistor inside the feedback loop. The OP27 is unity-gain stable.
Thermoelectric voltages generated by dissimilar metals at the input terminal contacts can degrade the drift performance. Best operation will be obtained when both input contacts are main­tained at the same temperature.

OFFSET VOLTAGE ADJUSTMENT

The input offset voltage of the OP27 is trimmed at wafer level. However, if further adjustment of V potentiometer can be used. TCV
is necessary, a 10 k trim
OS
is not degraded (see Offset
OS
Nulling Circuit). Other potentiometer values from 1 k to 1 M can be used with a slight degradation (0.1 µV/°C to 0.2 µV/°C) of TCV
. Trimming to a value other than zero creates a drift of
OS
approximately (V TCV
will be 0.33 µV/°C if VOS is adjusted to 100 µV. The
OS
/300) µV/°C. For example, the change in
OS
offset voltage adjustment range with a 10 k potentiometer is ±4 mV. If smaller adjustment range is required, the nulling sensitivity can be reduced by using a smaller pot in conjuction with fixed resistors. For example, the network below will have a ±280 µV adjustment range.
1
V+
84.7k4.7k 1kPOT
Figure 2.

NOISE MEASUREMENTS

To measure the 80 nV peak-to-peak noise specification of the OP27 in the 0.1 Hz to 10 Hz range, the following precautions must be observed:
1. The device must be warmed up for at least five minutes. As shown in the warm-up drift curve, the offset voltage typically changes 4 µV due to increasing chip temperature after power-up. In the 10-second measurement interval, these temperature-induced effects can exceed tens-of­nanovolts.
2. For similar reasons, the device has to be well-shielded from air currents. Shielding minimizes thermocouple effects.
REV. A
–11–
Page 12
OP27
3. Sudden motion in the vicinity of the device can also “feedthrough” to increase the observed noise.
4. The test time to measure 0.1 Hz to 10 Hz noise should not exceed 10 seconds. As shown in the noise-tester frequency response curve, the 0.1 Hz corner is defined by only one zero. The test time of 10 seconds acts as an additional zero to eliminate noise contributions from the frequency band below 0.1 Hz.
5. A noise-voltage-density test is recommended when measuring noise on a large number of units. A 10 Hz noise-voltage­density measurement will correlate well with a 0.1 Hz to 10 Hz peak-to-peak noise reading, since both results are determined by the white noise and the location of the 1/f corner frequency.

UNITY-GAIN BUFFER APPLICATIONS

When Rf ≤ 100 Ω and the input is driven with a fast, large signal pulse (>1 V), the output waveform will look as shown in the pulsed operation diagram (Figure 3).
During the fast feedthrough-like portion of the output, the input protection diodes effectively short the output to the input and a current, limited only by the output short-circuit protection, will be drawn by the signal generator. With R capable of handling the current requirements (I the amplifier will stay in its active mode and a smooth transition will occur.
When R
> 2 k, a pole will be created with Rf and the amplifier’s
f
input capacitance (8 pF) that creates additional phase shift and reduces phase margin. A small capacitor (20 pF to 50 pF) in parallel with R
will eliminate this problem.
f
R
f
OP27
+
Figure 3. Pulsed Operation
COMMENTS ON NOISE
The OP27 is a very low-noise monolithic op amp. The outstanding input voltage noise characteristics of the OP27 are achieved mainly by operating the input stage at a high quiescent current. The input bias and offset currents, which would normally increase, are held to reasonable values by the input bias-current cancellation circuit. The OP27A/E has I
and IOS of only ±40 nA and 35 nA at 25°C
B
respectively. This is particularly important when the input has a high source resistance. In addition, many audio amplifier design­ers prefer to use direct coupling. The high I of previous designs have made direct coupling difficult, if not impossible, to use.
Voltage noise is inversely proportional to the square root of bias current, but current noise is proportional to the square root of bias current. The OP27’s noise advantage disappears when high source-resistors are used. Figures 4, 5, and 6 compare OP27’s observed total noise with the noise performance of other devices in different circuit applications.
500 , the output is
f
20 mA at 10 V);
L
2.8V/s
, VOS, and TCV
B
OS
12
/
 
2
+
S
  
Total Noise
Voltage Noise
()
 
Current Noise R
=
()
 
sistor Noise
Re
()
 
2
+
×
2
Figure 4 shows noise versus source-resistance at 1000 Hz. The same plot applies to wideband noise. To use this plot, multiply the vertical scale by the square root of the bandwidth.
100
50
1
OP08/108
OP07
10
5
5534
TOTAL NOISE – nV/ Hz
OP27/37
REGISTER
1
50 10k
NOISE ONLY
100 50k
500 1k 5k
RS – SOURCE RESISTANCE –
1 RS UNMATCHED
= RS1 = 10k, RS2 = 0
e.g. R
S
2 RS MATCHED
= 10k, RS1 = RS2 = 5k
e.g. R
S
R
S1
R
S2
2
Figure 4. Noise vs. Source Resistance (Including Resistor Noise) at 1000 Hz
At RS <1 k, the OP27s low voltage noise is maintained. With R
<1 k, total noise increases, but is dominated by the resis-
S
tor noise rather than current or voltage noise. lt is only beyond
of 20 k that current noise starts to dominate. The argument
R
S
can be made that current noise is not important for applica­tions with low to moderate source resistances. The crossover between the OP27, OP07, and OP08 noise occurs in the 15 kΩ to 40 k region.
Figure 5 shows the 0.1 Hz to 10 Hz peak-to-peak noise. Here the picture is less favorable; resistor noise is negligible and current noise becomes important because it is inversely proportional to the square root of frequency. The crossover with the OP07 occurs in the 3 k to 5 k range depending on whether bal­anced or unbalanced source resistors are used (at 3 k the I
B
and IOS error also can be three times the VOS spec.).
1k
OP08/108
500
5534
OP07
100
OP27/37
p-p NOISE – nV
50
REGISTER
10
50 10k
NOISE ONLY
100 50k
RS – SOURCE RESISTANCE –
1
2
1 RS UNMATCHED e.g. RS = RS1 = 10k, RS2 = 0
MATCHED
2 R
S
= 10k, RS1 = RS2 = 5k
e.g. R
S
500 1k 5k
R
S1
R
S2
Figure 5. Peak-to-Peak Noise (0.1 Hz to 10 Hz) as Source Resistance (Includes Resistor Noise)
–12–
REV. A
Page 13
OP27
Therefore, for low-frequency applications, the OP07 is better than the OP27/OP37 when R
> 3 k. The only exception is
S
when gain error is important. Figure 6 illustrates the 10 Hz noise. As expected, the results are between the previous two figures.
For reference, typical source resistances of some signal sources are listed in Table I.
Table I.
Source
Device Impedance Comments
Strain Gauge <500 Typically used in low-
frequency applications.
Magnetic <1500 Low is very important to Tapehead reduce self-magnetization
problems when direct coupling is used. OP27 I
can be
B
neglected.
Magnetic <1500 Similar need for low I
in
B
Phonograph direct coupled applications. Cartridges OP27 will not introduce any
self-magnetization problem.
Linear Variable <1500 Used in rugged servo-feedback Differential applications. Bandwidth of Transformer interest is 400 Hz to 5 kHz.
Open-Loop Gain
Frequency at OP07 OP27 OP37
3 Hz 100 dB 124 dB 125 dB 10 Hz 100 dB 120 dB 125 dB 30 Hz 90 dB 110 dB 124 dB
For further information regarding noise calculations, see Minimization of Noise in Op Amp Applications, Application Note AN-15.
100
50
OP08/108
1
2
Figure 7 is an example of a phono pre-amplifier circuit using the OP27 for A1; R1-R2-C1-C2 form a very accurate RIAA net­work with standard component values. The popular method to accomplish RIAA phono equalization is to employ frequency­dependent feedback around a high-quality gain block. Properly chosen, an RC network can provide the three necessary time constants of 3180, 318, and 75 µs.
1
For initial equalization accuracy and stability, precision metal film resistors and film capacitors of polystyrene or polypropy­lene are recommended since they have low voltage coefficients, dissipation factors, and dielectric absorption.
4
(High-K ceramic capacitors should be avoided here, though low-K ceramics such as NPO types, which have excellent dissipation factors and somewhat lower dielectric absorptioncan be considered for small values.)
MOVING MAGNET
CARTRIDGE INPUT
Ra
47.5k
Ca 150pF
A1
OP27
C4 (2) 220F
++
LF ROLLOFF
C3
0.47F
R1
97.6k
R2
7.87k
R3 100
G = 1kHz GAIN
C1
0.03F
C2
0.01F
R1
1 +
= 0.101 ( )
= 98.677 (39.9dB) AS SHOWN
R3
OUT IN
R4
75k
R5
100k
OUTPUT
Figure 7.
The OP27 brings a 3.2 nV/Hz voltage noise and 0.45 pA/Hz current noise to this circuit. To minimize noise from other sources, R3 is set to a value of 100 , which generates a voltage noise of 1.3 nV/Hz. The noise increases the 3.2 nV/Hz of the amplifier by only 0.7 dB. With a 1 k source, the circuit noise measures 63 dB below a 1 mV reference level, unweighted, in a 20 kHz noise bandwidth.
Gain (G) of the circuit at 1 kHz can be calculated by the expression:
OP07
10
5534
5
TOTAL NOISE – nV/ Hz
OP27/37
REGISTER
1
50 10k
NOISE ONLY
100 50k
500 1k 5k
RS – SOURCE RESISTANCE –
1 RS UNMATCHED
= RS1 = 10k, RS2 = 0
e.g. R
S
2 RS MATCHED
= 10k, RS1 = RS2 = 5k
e.g. R
S
R
S1
R
S2
Figure 6. 10 Hz Noise vs. Source Resistance (Includes Resistor Noise)

AUDIO APPLICATIONS

The following applications information has been abstracted from a PMI article in the 12/20/80 issue of Electronic De­sign magazine and updated.
REV. A
–13–
R
G
=+
0 101 1
.
1
R
3
For the values shown, the gain is just under 100 (or 40 dB). Lower gains can be accommodated by increasing R3, but gains higher than 40 dB will show more equalization errors because of the 8 MHz gain-bandwidth of the OP27.
This circuit is capable of very low distortion over its entire range, generally below 0.01% at levels up to 7 V rms. At 3 V output levels, it will produce less than 0.03% total harmonic distortion at frequencies up to 20 kHz.
Capacitor C3 and resistor R4 form a simple –6 dB-per-octave rumble filter, with a corner at 22 Hz. As an option, the switch­selected shunt capacitor C4, a nonpolarized electrolytic, bypasses the low-frequency rolloff. Placing the rumble filters high-pass action after the preamp has the desirable result of discriminating
Page 14
OP27
against the RlAA-amplified low-frequency noise components and pickup-produced low-frequency disturbances.
A preamplifier for NAB tape playback is similar to an RIAA phono preamp, though more gain is typically demanded, along with equalization requiring a heavy low-frequency boost. The circuit in Figure 7 can be readily modified for tape use, as shown by Figure 8.
TA P E
HEAD
OP27
Ca
Ra
+
R2
5k
100k
R1
33k
0.01F
0.47F
T1 = 3180s T2 = 50s
15k
Figure 8.
While the tape-equalization requirement has a flat high-frequency gain above 3 kHz (T
= 50 µs), the amplifier need not be stabilized
2
for unity gain. The decompensated OP37 provides a greater bandwidth and slew rate. For many applications, the idealized time constants shown may require trimming of R1 and R2 to optimize frequency response for nonideal tapehead performance and other factors.
5
The network values of the configuration yield a 50 dB gain at 1 kHz, and the dc gain is greater than 70 dB. Thus, the worst-case output offset is just over 500 mV. A single 0.47 µF output capaci- tor can block this level without affecting the dynamic range.
The tapehead can be coupled directly to the amplifier input, since the worst-case bias current of 80 nA with a 400 mH, 100 µ inch head (such as the PRB2H7K) will not be troublesome.
One potential tapehead problem is presented by amplifier bias­current transients which can magnetize a head. The OP27 and OP37 are free of bias-current transients upon power-up or power­down. However, it is always advantageous to control the speed of power supply rise and fall, to eliminate transients.
In addition, the dc resistance of the head should be carefully controlled, and preferably below 1 kS2. For this configuration, the bias-current-induced offset voltage can be greater than the 100pV maximum offset if the head resistance is not sufficiently controlled.
A simple, but effective, fixed-gain transformerless microphone preamp ( Figure 9) amplifies differential signals from low imped­ance microphones by 50 dB, and has an input impedance of 2 kΩ. Because of the high working gain of the circuit, an OP37 helps to preserve bandwidth, which will be 110 kHz. As the OP37 is a decompensated device (minimum stable gain of 5), a dummy resistor, Rp, may be necessary, if the microphone is to be unplugged. Otherwise the 100% feedback from the open input may cause the amplifier to oscillate.
Common-mode input-noise rejection will depend upon the match of the bridge-resistor ratios. Either close-tolerance (0.1%) types should be used, or R4 should be trimmed for best CMRR. All resistors should be metal film types for best stability and low noise.
Noise performance of this circuit is limited more by the input resistors R1 and R2 than by the op amp, as R1 and R2 each gen­erate a 4 nV/Hz noise, while the op amp generates a 3.2 nV/Hz
–14–
noise. The rms sum of these predominant noise sources will be about 6 nV/Hz, equivalent to 0.9 µV in a 20 kHz noise band- width, or nearly 61 dB below a 1 mV input signal. Measurements confirm this predicted performance.
C1
5F
R6
100
R7 10k
OUTPUT
LOW IMPEDANCE
MICROPHONE INPUT
(Z = 50 TO 200 )
R3
R4
=
R1
R2
R1
1k
R2
1k
Rp 30k
R3
316k
OP27/
OP37
+
R4
316k
Figure 9.
For applications demanding appreciably lower noise, a high quality microphone transformer-coupled preamp (Figure 10) incorporates the internally compensated OP27. T1 is a JE-115K-E 150 /15 k transformer which provides an optimum source resistance for the OP27 device. The circuit has an overall gain of 40 dB, the product of the transformers voltage setup and the op amps voltage gain.
C2
1800pF
150
SOURCE
T1*
R1
121
R3
100
R2
1100
A1
OP27
*
T1 – JENSEN JE – 115K – E
JENSEN TRANSFORMERS 10735 BURBANK BLVD. N. HOLLYWOOD, CA 91601
OUTPUT
Figure 10.
Gain may be trimmed to other levels, if desired, by adjusting R2 or R1. Because of the low offset voltage of the OP27, the output offset of this circuit will be very low, 1.7 mV or less, for a 40 dB gain. The typical output blocking capacitor can be eliminated in such cases, but is desirable for higher gains to eliminate switch­ing transients.
+18V
OP27
–18V
Figure 11. Burn-In Circuit
Capacitor C2 and resistor R2 form a 2 µs time constant in this circuit, as recommended for optimum transient response by the transformer manufacturer. With C2 in use, A1 must have unity­gain stability. For situations where the 2 µs time constant is not necessary, C2 can be deleted, allowing the faster OP37 to be employed.
REV. A
Page 15
OP27
0.0098 (0.25)
0.0075 (0.19)
0.0500 (1.27)
0.0160 (0.41)
8 0
0.0196 (0.50)
0.0099 (0.25)
45
85
41
0.1968 (5.00)
0.1890 (4.80)
0.2440 (6.20)
0.2284 (5.80)
PIN 1
0.1574 (4.00)
0.1497 (3.80)
0.0500 (1.27) BSC
0.0688 (1.75)
0.0532 (1.35)
SEATING
PLANE
0.0098 (0.25)
0.0040 (0.10)
0.0192 (0.49)
0.0138 (0.35)
Some comment on noise is appropriate to understand the capability of this circuit. A 150 resistor and R1 and R2 gain resistors connected to a noiseless amplifier will generate 220 nV of noise in a 20 kHz bandwidth, or 73 dB below a 1 mV reference level. Any practical amplifier can only approach this noise level; it can never exceed it. With the OP27 and T1 specified, the additional noise degradation will be close to 3.6 dB (or –69.5 refer­enced to 1 mV).
R
P
INPUT
10k
OP27
V–
V+
OUTPUT
Figure 12. Offset Nulling Circuit
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
8-Lead PDIP Package (P-Suffix)
(N-8)
References
1. Lipshitz, S.R, On RIAA Equalization Networks, JAES, Vol. 27, June 1979, p. 458–481.
2. Jung, W.G., IC Op Amp Cookbook, 2nd. Ed., H.W. Sams and Company, 1980.
3. Jung, W.G., Audio IC Op Amp Applications, 2nd. Ed., H.W. Sams and Company, 1978.
4. Jung, W.G., and Marsh, R.M., Picking Capacitors,Audio, February and March, 1980.
5. Otala, M., Feedback-Generated Phase Nonlinearity in Audio Amplifiers, London AES Convention, March 1980, preprint 1976.
6. Stout, D.F., and Kautman, M., Handbook of Operational Amplifier Circuit Design, New York, McGraw-Hill, 1976.
8-Lead SOIC Package (S-Suffix)
(R-8)
REV. A
0.210
(5.33)
0.160 (4.06)
0.115 (2.93)
0.200 (5.08)
0.200 (5.08)
0.125 (3.18)
0.430 (10.92)
0.348 (8.84)
PIN 1
MAX
0.022 (0.558)
0.014 (0.356)
8
0.100 (2.54)
1
BSC
5
4
0.070 (1.77)
0.045 (1.15)
0.280 (7.11)
0.240 (6.10)
0.060 (1.52)
0.015 (0.38)
0.130 (3.30) MIN
SEATING PLANE
0.325 (8.25)
0.300 (7.62)
0.015 (0.381)
0.008 (0.204)
8-Lead CERDIP Package (Z-Suffix)
(Q-8)
0.005 (0.13) MIN
PIN 1
MAX
0.023 (0.58)
0.014 (0.36)
0.055 (1.4) MAX
85
1
4
0.100 (2.54) BSC
0.405 (10.29) MAX
0.070 (1.78)
0.030 (0.76)
0.310 (7.87)
0.220 (5.59)
0.060 (1.52)
0.015 (0.38)
0.150 (3.81) MIN
SEATING PLANE
15 0
0.320 (8.13)
0.290 (7.37)
0.195 (4.95)
0.115 (2.93)
0.015 (0.38)
0.008 (0.20)
–15–
8-Pin (TO-99) Header Package (J-Suffix)
0.185 (4.70)
0.165 (4.19)
0.370 (9.40)
0.335 (8.51)
0.335 (8.51)
0.305 (7.75)
0.040 (1.02) MAX
0.045 (1.14)
0.010 (0.25)
(H-8A)
REFERENCE PLANE
0.750 (19.05)
0.500 (12.70)
0.250 (6.35) MIN
0.050 (1.27) MAX
0.200
(5.08)
BSC
0.019 (0.48)
0.016 (0.41)
0.021 (0.53)
0.016 (0.41)
BASE & SEATING PLANE
0.100 (2.54) BSC
4
3
2
0.100 (2.54)
BSC
5
1
0.034 (0.86)
0.027 (0.69)
0.160 (4.06)
0.110 (2.79)
6
0.045 (1.14)
0.027 (0.69)
7
8
45 BSC
Page 16

Revision History

Location Page
9/01—Data Sheet changed from REV. 0 to REV. A.
Edits to ORDERING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Edits to PIN CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Edits to ABSOLUTE MAXIMUM RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Edits to PACKAGE TYPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Edits to ELECTRICAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2, 3
Edits to WAFER TEST LIMITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Deleted TYPICAL ELECTRICAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Edits to BURN-IN CIRCUIT figure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Edits to APPLICATION INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
C00317–0–1/02(A)
–16–
PRINTED IN U.S.A.
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