30 V, High Speed, Low Noise, Low Bias
Current, JFET Operational Amplifier
ADA4627-1/ADA4637-1
Data Sheet
PIN CONFIGURATIONS
Low offset voltage: 200 μV maximum
Offset drift: 1 μV/°C typical
Very low input bias current: 5 pA maximum
Extended temperature range: −40°C to +125°C
±5 V to ±15 V dual supply
ADA4627-1 GBW: 19 MHz
ADA4637-1 GBW: 79 MHz
Voltage noise: 6.1 nV/√Hz at 1 kHz
ADA4627-1 slew rate: 82 V/μs
ADA4637-1 slew rate: 170 V/μs
High gain: 120 dB typical
High CMRR: 116 dB typical
High PSRR: 112 dB typical
NULL 1
–IN 2
ADA4627-1
+IN 3
TOP VIEW
(Not to Scale)
V– 4
8
NC
7
V+
6
OUT
5
NULL
07559-001
FEATURES
NC = NO CONNECT
NULL 1
–IN 2
ADA4637-1
+IN 3
TOP VIEW
(Not to Scale)
V– 4
8
NC
7
V+
6
OUT
5
NULL
07559-103
Figure 1. 8-Lead SOIC_N (R-8)
NC = NO CONNECT
Figure 2. 8-Lead SOIC_N (R-8)
NC 1
APPLICATIONS
–IN 2
High impedance sensors
Photodiode amplifier
Precision instrumentation
Phase-locked loop filters
High end, professional audio
DAC output amplifier
ATE
Medical
+IN 3
8 NC
ADA4627-1/
ADA4637-1
7 V+
6 OUT
TOP VIEW
5 NC
NOTES
1. NC = NO CONNECT.
2. IT IS RECOMMENDED
THAT THE EXPOSED PAD BE
CONNECTED TO V–.
07559-002
V– 4
Figure 3. 8-Lead LFCSP_VD (CP-8-13)
GENERAL DESCRIPTION
The ADA4627-1/ADA4637-1 are specified for both the
industrial temperature range of −25°C to +85°C and the
extended industrial temperature range of −40°C to +125°C. The
ADA4627-1/ADA4637-1 are available in tiny 8-lead LFCSP and
8-lead SOIC packages.
The ADA4627-1/ADA4637-1 are wide bandwidth precision
amplifiers featuring low noise, very low offset, drift, and bias
current. The devices operate from ±5 V to ±15 V dual supply.
The ADA4627-1/ADA4637-1 provide benefits previously found
in few amplifiers. These amplifiers combine the best specifications
of precision dc and high speed ac op amps. The ADA4637-1 is
a decompensated version of the ADA4627-1 and is stable at a
noise gain of 5 or greater.
The ADA4627-1/ADA4637-1 are members of a growing series
of high speed, precision op amps offered by Analog Devices, Inc.
(see Table 1).
With a typical offset voltage of only 70 μV, drift of less than
1 μV/°C, and noise of only 0.86 μV p-p (0.1 Hz to 10 Hz), the
ADA4627-1/ADA4637-1 are suited for applications where error
sources cannot be tolerated.
Table 1. High Speed Precision Op Amps
Supply
5 V Low Cost
5V
26 V Low Power
30 V Low Cost
30 V
Single
Dual
Quad
AD8615
AD8616
AD8618
AD8651
AD8652
AD8610
AD8620
AD8510
AD8512
AD8513
ADA4627-1/ADA4637-1
Rev. F
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Technical Support
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ADA4627-1/ADA4637-1
Data Sheet
TABLE OF CONTENTS
Features .............................................................................................. 1
Input Voltage Range ................................................................... 14
Applications ....................................................................................... 1
Input Offset Voltage Adjust Range........................................... 14
Pin Configurations ........................................................................... 1
Input Bias Current ...................................................................... 14
General Description ......................................................................... 1
Noise Considerations ................................................................. 14
Revision History ............................................................................... 2
THD + N Measurements ........................................................... 15
Specifications..................................................................................... 3
Printed Circuit Board Layout, Bias Current, and Bypassing 15
Electrical Characteristics—30 V Operation ............................. 3
Output Phase Reversal ............................................................... 15
Absolute Maximum Ratings............................................................ 5
Decompensated Op Amps ........................................................ 16
Thermal Resistance ...................................................................... 5
Driving Capacitive Loads .......................................................... 16
ESD Caution .................................................................................. 5
Outline Dimensions ....................................................................... 17
Typical Performance Characteristics ............................................. 6
Ordering Guide .......................................................................... 18
Theory of Operation ...................................................................... 14
REVISION HISTORY
6/15—Rev. E to Rev. F
Changes to Figure 3 .......................................................................... 1
Change to Total Harmonic Distortion + Noise Parameter,
Table 2 ................................................................................................ 4
Changes to Figure 17 and Figure 19............................................... 8
Changes to Figure 52 ...................................................................... 17
Changes to Ordering Guide .......................................................... 18
Changes to Table 2.............................................................................3
Change to Table 3 ..............................................................................5
Changes to Typical Performance Characteristics Section ...........6
Updated Outline Dimensions ....................................................... 17
Changes to Ordering Guide .......................................................... 18
10/09—Rev. A to Rev. B
Changes to Figure 2...........................................................................1
1/14—Rev. D to Rev. E
Changes to Output Phase Reversal Section ................................ 15
9/09—Rev. 0 to Rev. A
Changes to Figure 1 and General Description Section ............... 1
Changes to Ordering Guide .......................................................... 18
Changes to General Description Section .......................................1
Changes to Table 2.............................................................................3
Updated Outline Dimensions ....................................................... 14
Changes to Ordering Guide .......................................................... 15
7/10—Rev. B to Rev. C
7/09—Revision 0: Initial Version
10/10—Rev. C to Rev. D
Added ADA4637-1 ............................................................. Universal
Added Figure 2; Renumbered Sequentially .................................. 1
Rev. F | Page 2 of 20
Data Sheet
ADA4627-1/ADA4637-1
SPECIFICATIONS
ELECTRICAL CHARACTERISTICS—30 V OPERATION
VSY = ±15 V, VCM = 0 V, TA = 25°C, unless otherwise noted.
Table 2.
Parameter
INPUT CHARACTERISTICS
Offset Voltage 1
Symbol
Test Conditions/Comments
Min
VOS
B Grade
Typ
70
Offset Voltage Drift,
Average
Power Supply Rejection
Ratio
∆VOS/∆T
−40°C ≤ TA ≤ +85°C
−40°C ≤ TA ≤ +125°C
−40°C ≤ TA ≤ +125°C
PSRR
VSY = ±4.5 V to ±18 V
106
−40°C ≤ TA ≤ +125°C
101
Input Bias Current 2
IB
1
0.5
−40°C ≤ TA ≤ +85°C
−40°C ≤ TA ≤ +125°C
NOISE PERFORMANCE
Voltage Noise Density
Voltage Noise
Current Noise Density
Current Noise
Input Resistance
Input Capacitance,
Differential Mode
Input Capacitance,
Common Mode
Input Voltage Range
Common-Mode
Rejection Ratio
Large Signal Voltage Gain
DYNAMIC PERFORMANCE
Slew Rate ADA4627-1
en
en p-p
in
in p-p
RIN
CINDM
16.5
7.9
6.1
4.8
0.7
1.6
30
10
8
CINCM
−40°C ≤ TA ≤ +125°C
−11
−10.5
CMRR
TA = 25°C, VCM = −11 V to +11 V
106
98
AVO
−40°C ≤ TA ≤ +125°C,
VCM = −10.5 V to +10.5 V
RL = 1 kΩ, VO = −10 V to +10 V
−40 ≤ TA ≤ +85°C
−40 ≤ TA ≤ +125°C
SR
SR
SR
120
1
103
5
0.5
2
5
0.5
2
±10 V step, RL = 1 kΩ,
CL = 100 pF, AV = +1
±10 V step, RL = 1 kΩ, CL = 100 pF,
Rs = Rf = 1 kΩ, AV = −1
±10 V out, Cf = 4.8 pF, AV = −4
±10 V out, Cf = 4.8 pF, AV = +5
Max
Unit
300
410
660
3
µV
µV
µV
µV/°C
108
1
0.5
40
20
8
6
1.6
16.5
7.9
6.1
4.8
0.7
2.5
48
10
8
7
IVR
SR
Slew Rate ADA4637-1
f = 10 Hz
f = 100 Hz
f = 1 kHz
f = 10 kHz
0.1 Hz to 10 Hz
f = 100 Hz
0.1 Hz to 10 Hz
A Grade
Typ
dB
99
1
IOS
Min
200
350
400
2
112
−40°C ≤ TA ≤ +85°C
−40°C ≤ TA ≤ +125°C
Input Offset Current
Max
40
20
8
6
1.6
7
+11
+10.5
116
5
0.5
2
5
0.5
2
−11
−10.5
100
nV/√Hz
nV/√Hz
nV/√Hz
nV/√Hz
µV p-p
fA/√Hz
fA p-p
TΩ
pF
pF
+11
+10.5
110
dB
pA
nA
nA
pA
nA
nA
V
V
dB
97
dB
dB
dB
dB
112
110
102
120
106
104
100
120
40
56/78 3
40
56/783
V/µs
40
82/843
40
82/843
V/µs
170
170
V/µs
V/µs
Rev. F | Page 3 of 20
170
170
ADA4627-1/ADA4637-1
Parameter
Settling Time to 0.01%
ADA4627-1
Symbol
tS
ADA4637-1
Settling Time to 0.1%
ADA4627-1
Test Conditions/Comments
Min
B Grade
Typ
Min
A Grade
Typ
Max
Unit
VIN = 10 V step, CL = 35 pF,
RL = +1 kΩ, AV = −1
VIN = 10 V step, CL = 35 pF,
RL = +1 kΩ, AV = −4
550
550
ns
300
300
ns
VIN = 10 V step, CL = 35 pF,
RL = +1 kΩ, AV = −1
VOUT = 10 V step, CL = 35 pF,
RL = +1 kΩ, AV = −4
450
450
ns
200
200
ns
19
79.9
MHz
72
85
0.000045
Degrees
GBP
RL = 1 kΩ, CL = 20 pF, AV = 1
AV = 10
16 4
19
79.9
164
ΦM
THD + N
ISY
RL = 1 kΩ, CL = 20 pF, AV = 1
AV = 10
VIN = 6 V rms, f = 1 kHz, AV = 1,
ADA4627-1
72
85
0.000045
IO = 0 mA
±7.0
−40°C ≤ TA ≤ +125°C
OUTPUT CHARACTERISTICS
Output Voltage High
Max
tS
ADA4637-1
Gain Bandwidth Product
ADA4627-1
ADA4637-1
Phase Margin
ADA4627-1
ADA4637-1
Total Harmonic
Distortion + Noise
POWER SUPPLY
Supply Current per
Amplifier
Data Sheet
VOH
Output Voltage Low
VOL
Output Current
Short-Circuit Current
Closed-Loop Output
Impedance
IOUT
ISC
ZOUT
RL = 1 kΩ to VCM
−40°C ≤ TA ≤ +85°C
−40°C ≤ TA ≤ +125°C
RL = 1 kΩ to VCM
−40°C ≤ TA ≤ +85°C
−40°C ≤ TA ≤ +125°C
VO = ±10 V
TA = 25°C
f = 1 MHz, AV = −100
±7.5
±7.0
±7.8
12.0
11.8
11.7
12.3
−12.7
±45
+70/−55
41
VOS is measured fully warmed up.
Tested/extrapolated from 125°C.
3
Rising/falling.
4
Not tested. Guaranteed by simulation and characterization.
1
2
Rev. F | Page 4 of 20
12.0
11.8
11.7
−12.3
−12.1
−12.0
%
±7.5
mA
±7.8
mA
−12.3
−12.1
−12.0
V
V
V
V
V
V
mA
mA
Ω
12.3
−12.7
±45
+70/−55
41
Data Sheet
ADA4627-1/ADA4637-1
ABSOLUTE MAXIMUM RATINGS
THERMAL RESISTANCE
Table 3.
Parameter
Supply Voltage
Input Voltage Range1
Input Current1
Differential Input Voltage2
Output Short-Circuit Duration to GND
Storage Temperature Range
Operating Temperature Range
Junction Temperature Range
Lead Temperature (Soldering, 60 sec)
ESD Human Body Model
Rating
36 V
(V−) − 0.3 V to (V+) + 0.3 V
±10 mA
±VSY
Indefinite
−65°C to +150°C
−40°C to +125°C
−65°C to +150°C
300°C
4 kV
θJA is specified for the worst-case conditions, that is, a device
soldered in a circuit board for surface-mount packages. This
was measured using a standard 2-layer board. For the LFCSP
package, the exposed pad should be soldered to a copper plane.
Table 4. Thermal Resistance
Package Type
8-Lead SOIC_N (R-8)
8-Lead LFCSP (CP-8-2)
ESD CAUTION
Input pin has clamp diodes to the power supply pins. Input current should
be limited to 10 mA or less whenever input signals exceed the power supply
rail by 0.3 V.
2
Differential input voltage is limited to ±30 V or the supply voltage,
whichever is less.
1
Stresses at or above those listed under Absolute Maximum
Ratings may cause permanent damage to the product. This is a
stress rating only; functional operation of the product at these
or any other conditions above those indicated in the operational
section of this specification is not implied. Operation beyond
the maximum operating conditions for extended periods may
affect product reliability.
Rev. F | Page 5 of 20
θJA
155
77
θJC
45
14
Unit
°C/W
°C/W
ADA4627-1/ADA4637-1
Data Sheet
TYPICAL PERFORMANCE CHARACTERISTICS
TA = 25°C, unless otherwise noted.
120
10
ADA4627-1
TA = 25°C
VSY = ±15V
80
60
78°
40
20
0
ADA4627-1
TA = 25°C
VSY = ±15V
–20
1
0.01
0.1
1
FREQUENCY (kHz)
10
19.1MHz
–40
1k
Figure 4. Voltage Noise Density vs. Frequency
10k
100k
1M
FREQUENCY (Hz)
10M
100M
07559-006
GAIN (dB) AND PHASE (Degrees)
100
07559-003
VOLTAGE NOISE DENSITY (nV/√Hz)
100
Figure 7. Open-Loop Gain and Phase vs. Frequency
140
100
10
AV = –10
RL = 600Ω
100
ZOUT (Ω)
80
25
50
TEMPERATURE (°C)
75
100
125
0.01
100
100
100
80
50
VOS (µV)
150
60
40
100k
1M
FREQUENCY (Hz)
10M
100M
0
–50
ADA4627-1
TA = 25°C
VSY = ±15V
1k
ADA4627-1
TA = 25°C
VSY = ±15V
–100
07559-010
CMRR (dB)
10k
Figure 8. Closed-Loop ZOUT vs. Frequency
120
0
100
1k
07559-007
0
Figure 5. Open-Loop Gain vs. Temperature
20
AV = –1
ADA4627-1
TA = 25°C
VSY = ±15V
07559-004
–25
AV = –100
0.1
ADA4627-1
TA = 25°C
VSY = ±15V
VO = ±11V
60
–50
1
10k
100k
FREQUENCY (Hz)
1M
–150
–15
10M
Figure 6. CMRR vs. Frequency
–10
–5
07559-069
OPEN-LOOP GAIN (dB)
RL = 1kΩ
120
0
VCM (V)
5
Figure 9. VOS vs. Common-Mode Voltage
Rev. F | Page 6 of 20
10
15
Data Sheet
ADA4627-1/ADA4637-1
120
100
60
PSRR–
PSRR+
40
ADA4627-1
TA = 25°C
VSY = ±15V
20
0
100
1k
10k
100k
1M
10M
FREQUENCY (Hz)
100
90
80
70
60
–50
07559-009
PSRR (dB)
80
110
–25
0
25
50
75
100
125
TEMPERATURE (°C)
Figure 10. PSRR vs. Frequency
Figure 13. CMRR vs. Temperature
8
20
–40ºC
ADA4627-1
TA = 25°C
VSY = ±15V
7
+25ºC
6
+85ºC
10
+125ºC
5
VOL – VSS (V)
SUPPLY CURRENT (mA)
ADA4627-1
VSY = ±15V
VCM = ±11.5V
07559-012
COMMON-MODE REJECTION RATIO (dB)
120
4
3
2
ADA4627-1
0
4
8
12
16
20
24
SUPPLY VOLTAGE (V)
28
32
36
1
0.001
07559-011
0
Figure 11. Supply Current vs. Supply Voltage and Temperature
07559-058
1
0.01
0.1
1
ILOAD (mA)
10
100
Figure 14. VOUT Sinking vs. ILOAD Current
20
120
ADA4627-1
TA = 25°C
VSY = ±15V
ADA4627-1
RL = ∞
±4.5V < VSY < ±18V
100
–40
–20
0
20
40
60
TEMPERATURE (°C)
80
100
1
0.001
120
07559-057
VDD – VOH (V)
110
07559-068
PSRR (dB)
10
0.01
0.1
1
ILOAD (mA)
10
Figure 15. VOUT Sourcing vs. ILOAD Current
Figure 12. PSRR vs. Temperature
Rev. F | Page 7 of 20
100
ADA4627-1/ADA4637-1
Data Sheet
8
0.01
ADA4627-1
TA = 25°C
VSY = ±15V
VIN = 6V rms
RL = 600Ω
80kHz FILTER
6
0.001
THD + N (%)
5
4
3
0.0001
2
0
0
4
8
12
16
20
24
28
32
SUPPLY VOLTAGE (V)
36
07559-071
ADA4627-1
TA = 25°C
SOIC PACKAGE
1
0.00001
0.01
07559-015
SUPPLY CURRENT (mA)
7
0.1
1
FREQUENCY (kHz)
10
Figure 19. THD + N vs. Frequency
Figure 16. Supply Current vs. Supply Voltage
10,000
0.1
ADA4627-1
VSY = ±15V
1,000
0.01
MEASURED
IB (pA)
THD + N (%)
100
0.001
10
ADA4627-1
TA = 25°C
VSY = ±15V
VIN = 1kHz
RL = 600Ω
80kHz FILTER
0.1
y = 0.28950.0647x
R2 = 0.9991
1
AMPLITUDE (V rms)
07559-078
0.00001
0.01
EXTRAPOLATED
1
07559-072
0.0001
0.1
10
10
30
50
70
90
TEMPERATURE (°C)
110
130
Figure 20. Input Bias Current vs. Temperature
Figure 17. THD + N vs. VIN
100
60
ADA4627-1
TA = 25°C
VSY = ±15V
50
IB+
75
+85°C
IB–
50
40
25
IB (pA)
30
20
AV = +10
IB+
+25ºC
0
IB–
–25
10
–50
AV = +1
–10
–20
10
100
1k
10k
100k
FREQUENCY (kHz)
1M
10M
ADA4627-1
VSY = ±15V
–75
–100
–15
100M
–10
07559-073
0
07559-070
GAIN (dB)
AV = +100
–5
0
VCM (V)
5
10
Figure 21. Input Bias Current vs. VCM and Temperature
Figure 18. Closed-Loop Gain vs. Frequency
Rev. F | Page 8 of 20
15
Data Sheet
ADA4627-1/ADA4637-1
1200
1100
OUTPUT VOLTAGE (5V/DIV)
IB +
900
IB (pA)
800
IB –
700
600
500
400
200
100
0
–15
–10
ADA4627-1
TA = 25°C
AV = –1
VIN = 20V p-p
RF = RIN = 2kΩ
CF = 10pF
RL = 1kΩ
CL = 1nF
07559-074
ADA4627-1
TA = 125°C
VSY = ±15V
300
1
–5
0
VCM (V)
5
10
07559-061
1000
TIME (1µs/DIV)
15
Figure 22. Input Bias Current vs. VCM at 125°C
Figure 25. Large Signal Transient Response
80
ADA4627-1
TA = 25°C
VSY = ±15V
OUTPUT VOLTAGE (5V/DIV)
60
40
VOS (µV)
20
0
–20
–80
07559-075
–60
1
07559-062
–40
ADA4627-1
TA = 25°C
AV = +1
VIN = 20V p-p
RF = 0Ω
0
60
120
180
TIME (Seconds)
240
TIME (200ns/DIV)
300
Figure 23. Input Offset Voltage vs. Time
Figure 26. Large Signal Transient Response
60
OUTPUT VOLTAGE (5V/DIV)
OS–
40
20
ADA4627-1
TA = 25°C
VSY = ±15V
AV = +1
VIN = 100mV p-p
10
0
1
10
100
1000
LOAD CAPACITANCE (pF)
1
07559-059
OS+
30
07559-023
OVERSHOOT (%)
50
ADA4627-1
TA = 25°C
AV = –1
VIN = 20V p-p
RF = RIN = 2kΩ
CH1 5.00V
10,000
TIME (200ns/DIV)
Figure 27. Large Signal Transient Response
Figure 24. Small Signal Overshoot vs. Load Capacitance
Rev. F | Page 9 of 20
1
ADA4627-1
TA = 25°C
AV = –1
VIN = 200mV p-p
RF = RIN = 2kΩ
CF = 5pF
TIME (1µs/DIV)
TIME (200ns/DIV)
Figure 31. Small Signal Transient Response
1
1
ADA4627-1
TA = 25°C
AV = +1
VIN = 200mV p-p
RF = 0Ω
RL = 1kΩ
CL = 1nF
TIME (200ns/DIV)
TIME (200ns/DIV)
Figure 32. Small Signal Transient Response
OUTPUT VOLTAGE (50mV/DIV)
Figure 29. Large Signal Transient Response
1
ADA4627-1
TA = 25°C
AV = +1
VIN = 200mV p-p
RF = 0Ω
07559-064
OUTPUT VOLTAGE (50mV/DIV)
07559-065
OUTPUT VOLTAGE (50mV/DIV)
ADA4627-1
TA = 25°C
AV = –1
VIN = 20V p-p
RF = RIN = 2kΩ
CF = 10pF
RL = 1kΩ
CL = 100pF
07559-060
OUTPUT VOLTAGE (5V/DIV)
Figure 28. Large Signal Transient Response
TIME (200ns/DIV)
1
ADA4627-1
TA = 25°C
AV = –1
VIN = 200mV p-p
RF = RIN = 2kΩ
CF = 5pF
RL = 1kΩ
CL = 100pF
TIME (200ns/DIV)
Figure 30. Small Signal Transient Response
Figure 33. Small Signal Transient Response
Rev. F | Page 10 of 20
07559-067
ADA4627-1
TA = 25°C
AV = +1
VIN = 20V p-p
RF = 0Ω
RL = 1kΩ
CL = 1nF
1
07559-066
OUTPUT VOLTAGE (50mV/DIV)
Data Sheet
07559-063
OUTPUT VOLTAGE (5V/DIV)
ADA4627-1/ADA4637-1
Data Sheet
ADA4627-1/ADA4637-1
20
INPUT VOLTAGE (5V/DIV)
1
10
AMPLITUDE (V)
ADA4627-1
TA = 25°C
VSY = ±15
5
0
–5
VOUT
–10
OUTPUT VOLTAGE (1mV/DIV)
ADA4627-1
TA = 25°C
VSY = ±15V
15
VOUT
2
VIN
07559-077
–15
VIN
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
TIME (ms)
TIME (200ns/DIV)
Figure 37. Positive Settling Time to 0.01%
VIN
2
VOUT
1
ADA4627-1
TA = 25°C
VSY = ±15V
DUT GAIN = 100
4TH ORDER BAND PASS FIXTURE GAIN = 10k
TOTAL GAIN = 1M
07559-076
INPUT VOLTAGE (5V/DIV)
OUTPUT VOLTAGE (1mV/DIV)
ADA4627-1
TA = 25°C
VSY = ±15
1
OUTPUT VOLTAGE (200mV/DIV)
Figure 34. No Phase Reversal
07559-040
0
07559-033
–20
TIME (1s/DIV)
TIME (200ns/DIV)
Figure 35. Negative Settling Time to 0.01%
Figure 38. 0.1 Hz to 10 Hz Noise
140
100
PHASE
100
80
80
60
CMRR (dB)
GAIN
40
20
–40
–60
–80
ADA4637-1
VSY = ±15V
TA = 25ºC
AV = –4
RIN = 500Ω
RF = 2kΩ
CF = 4.8pF
CL = 35pF
–100
10k
60
40
20
100k
1M
10M
FREQUENCY (Hz)
100M
0
10
ADA4637-1
VSY = ±15V
TA = 25ºC
100
1k
10k
100k
1M
FREQUENCY (Hz)
Figure 39. CMRR vs. Frequency
Figure 36. Open-Loop Gain and Phase vs. Frequency
Rev. F | Page 11 of 20
10M
100M
07559-083
0
–20
07559-082
GAIN (dB) AND PHASE (Degrees)
120
ADA4627-1/ADA4637-1
Data Sheet
120
PSRR+
OUTPUT VOLTAGE (100mV/DIV)
100
PSRR–
PSRR (dB)
80
60
40
100
07559-085
0
10
ADA4637-1
VSY = ±15V
AV = +5
TA = 25°C
1k
10k
100k
1M
10M
100M
FREQUENCY (Hz)
07559-081
20
ADA4637-1
TA = 25°C
AV = +5
VSY = ±15V
RIN = 500Ω
RF = 2kΩ
CF = 4.8pF
CL = 50pF
TIME (200ns/DIV)
Figure 43. Small Signal Transient Response
Figure 40. PSRR vs. Frequency
50
ADA4637-1
TA = 25°C
AV = –4
VSY = ±15V
RIN = 500Ω
RF = 2kΩ
CF = 4.8pF
AV = +100
OUTPUT VOLTAGE (5V/DIV)
40
AV = +10
20
10
AV = +5
–10
100
1k
07559-086
ADA4637-1
VSY = ±15V
RF = 1kΩ,
CF = 4.8pF
TA = 25ºC
10k
100k
1M
10M
100M
FREQUENCY (Hz)
TIME (100ns/DIV)
07559-079
0
Figure 44. Slew Rate Falling
Figure 41. Closed-Loop Gain vs. Frequency
ADA4637-1
TA = 25°C
AV = –4
VSY = ±15V
RIN = 500Ω
RF = 2kΩ
CF = 4.8pF
07559-087
OUTPUT VOLTAGE (5V/DIV)
ADA4637-1
TA = 25°C
AV = +5
VSY = ±15V
RIN = 500Ω
RF = 2kΩ
CF = 3pF
07559-084
OUTPUT VOLTAGE (5V/DIV)
GAIN (dB)
30
TIME (200ns/DIV)
TIME (100ns/DIV)
Figure 42. Large Signal Transient Response
Figure 45. Slew Rate Rising
Rev. F | Page 12 of 20
Data Sheet
ADA4627-1/ADA4637-1
ADA4637-1
VSY = ±15V
VCM = 0V
TA = 25°C
10
1
1
10
100
1k
10k
FREQUENCY (Hz)
100k
07559-080
VOLTAGE NOISE DENSITY (nV/√Hz)
100
Figure 46. Voltage Noise Density vs. Frequency
Rev. F | Page 13 of 20
ADA4627-1/ADA4637-1
Data Sheet
THEORY OF OPERATION
use the offset adjust pins, especially for offset adjust of a
complete signal chain. Signal chain offset can be addressed with
an auto-zero amplifier used to form a composite amplifier; or, if
the ADA4627-1 or the ADA4637-1 is in an inverting amplifier
stage, it can be modified easily to add a potentiometer (see
Figure 48). The LFCSP package does not have offset adjust pins.
RF
RIN
INPUT VOLTAGE RANGE
The ADA4627-1/ADA4637-1 are not rail-to-rail input
amplifiers; therefore, care is required to ensure that both inputs
do not exceed the input voltage range. Under normal negative
feedback operating conditions, the amplifier corrects its output
to ensure that the two inputs are at the same voltage. However,
if either input exceeds the input voltage range, the loop opens,
and large currents begin to flow through the ESD protection
diodes in the amplifier.
These diodes are connected between the inputs and each supply
rail to protect the input transistors against an electrostatic discharge
event, and they are normally reverse-biased. However, if the input
voltage exceeds the supply voltage, these ESD diodes can become
forward-biased. Without current limiting, excessive amounts
of current can flow through these diodes, causing permanent
damage to the device. If inputs are subject to overvoltage, insert
appropriate series resistors to limit the diode current to less
than 5 mA.
INPUT OFFSET VOLTAGE ADJUST RANGE
The ADA4627-1/ADA4637-1 SOIC packages have offset
adjust pins for compatibility with some existing designs. The
recommended offset nulling circuit is shown in Figure 47.
+VS
2
1
5
ADA4627-1
6
3
07559-051
4
–VS
ADA4627-1
+
VIN
3
+VS
–
499kΩ
6
499kΩ
200Ω
0.1µF
+
VOUT
–
100kΩ
–VS
Figure 48. Alternate Offset Null Circuit for Inverting Stage
INPUT BIAS CURRENT
Because the ADA4627-1/ADA4637-1 have a JFET input stage,
the input bias current, due to the reverse-biased junction, has
a leakage current that approximately doubles every 10°C. The
power dissipation of the device, combined with the thermal
resistance of the package, results in the junction temperature
increasing 20°C to 30°C above ambient. This parameter is tested
with high speed ATE equipment, which does not result in the die
temperature reaching equilibrium. This is correlated with bench
measurements to match the guaranteed maximum at room
temperature shown in Table 2.
The input current can be reduced by keeping the temperature as
low as possible and using a light load on the output.
NOISE CONSIDERATIONS
The JFET input stage offers very low input voltage noise and
input current noise. The thermal noise of a 1 kΩ resistor at
room temperature is 4 nV/√Hz; therefore, low values of
resistance should be used for dc-coupled inverting and
noninverting amplifier configurations. In the case of
transimpedance amplifiers (TIAs), current noise is more
important.
100kΩ
7
2
07559-052
The ADA4627-1 is a high speed, unity gain stable amplifier with
excellent dc characteristics. The ADA4637-1 is a decompensated
version that is stable at a gain of 5 or greater. The typical offset
voltage of 70 μV allows the amplifiers to be easily configured for
high gains without the risk of excessive output voltage errors. The
small temperature drift of 2 μV/°C ensures a minimum offset
voltage error over the entire temperature range of −40°C to
+125°C, making the amplifiers ideal for a variety of sensitive
measurement applications in harsh operating environments.
Figure 47. Standard Offset Null Circuit
With a 100 kΩ potentiometer, the adjustment range is
more than ±11 mV. However, the VOS temperature drift
increases by several μV/°C for every millivolt of offset adjust.
The ADA4627-1/ADA4637-1 have matching thin film resistors
that are laser trimmed at two temperatures to minimize both
offset voltage and offset voltage drift. The offset voltage at room
temperature is less than 0.5 mV, and the offset voltage drift is
only a few μV/°C or less; therefore, it is not recommended to
The ADA4627-1/ADA4637-1 are an excellent choice for both of
these applications. Analog Devices offers a wide variety of low
voltage noise and low current noise op amps in a variety of
processes that are optimized for different supply voltage ranges.
Refer to Application Note AN-940 for a discussion of noise,
calculations, and selection tables for more than three dozen low
noise, op amp families.
Rev. F | Page 14 of 20
Data Sheet
ADA4627-1/ADA4637-1
CF
THD + N MEASUREMENTS
GUARD
Total harmonic distortion plus noise (THD + N) is usually
measured with an audio analyzer, such as those from Audio
Precision, Inc™. The analyzer consists of a low distortion
oscillator that is swept from the starting frequency to the
ending frequency. The oscillator is connected to the circuit
under test, and the output of the circuit goes back to the analyzer.
ADA4627-1
IN
07559-053
3
Figure 50. Inverting Amplifier with Guard
For a noninverting configuration, the trace can be driven from
the feedback divider, but the resistors should be chosen to offer
a low impedance drive to the trace (see Figure 51).
GUARD
3
ADA4627-1
+
VS
2
RF
RI
Figure 51. Noninverting Amplifier with Guard
The board layout should be compact with traces as short as
possible. For second-order board considerations, such as
triboelectric effects and piezoelectric effects, as well as a table
of insulating material properties, see the AD549 data sheet.
500kHz FILTER
07559-017
80kHz FILTER
0.00001
0.01
VOUT
+
–
ADA4627-1
TA = 25°C
VSY = ±15V
VIN = 810mV
RL = 600Ω
THD + N (%)
0.0001
8
6
–
0.01
0.001
+
VOUT
–
6
8
07559-054
The analyzer has a tunable notch filter in lock step with the
swept oscillator. This removes the fundamental frequency
but allows all of the harmonics and wideband noise to be
measured with an integrating voltmeter. However, there is a
switchable low-pass filter in series with the notch filter. If the
sine wave is at 100 Hz, then the tenth harmonic is still at 1 kHz;
therefore, having a low pass at 80 kHz is not a problem. When
the oscillator reaches 20 kHz, the fourth harmonic (80 kHz)
is partially attenuated, resulting in a lower reading from the
voltmeter. When evaluating THD + N curves from any
manufacturer, careful attention should be paid to the test
conditions. The difference between an 80 kHz low-pass filter
and a 500 kHz filter is shown in Figure 49.
RF
2
0.1
1
FREQUENCY (kHz)
10
100
Figure 49. THD + N vs. Frequency
In some cases, shielding from air currents may be helpful.
A general rule of thumb, for op amps with gain bandwidth
products higher than 1 MHz, bypass capacitors should be very
close to the device, within 3 mm. Each supply should be
bypassed with a 0.01 μF ceramic capacitor in parallel with a
1 F bulk decoupling capacitor. The ceramic capacitors should
be closer to the op amp. Sockets, which add inductance and
capacitance, should not be used.
OUTPUT PHASE REVERSAL
PRINTED CIRCUIT BOARD LAYOUT, BIAS
CURRENT, AND BYPASSING
To take advantage of the very low input bias current of the
ADA4627-1/ADA4637-1 at room temperature, leakage paths
must be considered. A printed circuit board (PCB), with dust
and humidity, can have 100 MΩ of resistance over a few tenths
of an inch. A 1 mV differential between the two points results in
10 pA of leakage current, more than the guaranteed maximum.
The op amp inputs should be guarded by surrounding the nets
with a metal trace maintained at the predicted voltage. In the
case of an inverting configuration or transimpedance amplifier,
(see Figure 50), the inverting and noninverting nodes can be
surrounded by traces held at a quiet analog ground.
Output phase reversal occurs in some amplifiers when the input
common-mode voltage range is exceeded. As common-mode
voltage is moved outside the common-mode range, the outputs
of these amplifiers can suddenly jump in the opposite direction
to the supply rail. This is the result of the differential input pair
shutting down, causing a radical shifting of internal voltages
that results in the erratic output behavior.
The ADA4627-1/ADA4637-1 amplifiers are carefully designed
to prevent any output phase reversal if both inputs are maintained
within or slightly above the power supply rails. The ADA4627-1/
ADA4637-1 do not phase reverse, as shown in Figure 34.
Rev. F | Page 15 of 20
ADA4627-1/ADA4637-1
Data Sheet
DECOMPENSATED OP AMPS
The ADA4627-1/ADA4637-1 have a high phase margin and low
output impedance, so they can drive reasonable values of
capacitance. This is a common situation when an amplifier is used
to drive the input of switched capacitor ADCs. For other
considerations and various circuit solutions, see the Analog
Dialogue article titled Ask the Applications Engineer-25, Op
Amps Driving Capacitive Loads.
The ADA4637-1 is a decompensated op amp, and, as such, must
always be operated at a noise gain of 5 or greater. See tutorial
MT-033, Voltage Feedback Op Amp Gain and Bandwidth, at
www.analog.com for more information.
DRIVING CAPACITIVE LOADS
Adding capacitance to the output of any op amp results in
additional phase shift, which reduces stability and leads to
overshoot or oscillation.
Rev. F | Page 16 of 20
Data Sheet
ADA4627-1/ADA4637-1
OUTLINE DIMENSIONS
1.84
1.74
1.64
3.10
3.00 SQ
2.90
0.50 BSC
8
5
PIN 1 INDEX
AREA
1.55
1.45
1.35
EXPOSED
PAD
0.50
0.40
0.30
PIN 1
INDICATOR
(R 0.15)
BOTTOM VIEW
0.05 MAX
0.02 NOM
COPLANARITY
0.08
0.203 REF
0.30
0.25
0.20
FOR PROPER CONNECTION OF
THE EXPOSED PAD, REFER TO
THE PIN CONFIGURATION AND
FUNCTION DESCRIPTIONS
SECTION OF THIS DATA SHEET.
12-07-2010-A
0.80
0.75
0.70
SEATING
PLANE
1
4
TOP VIEW
COMPLIANT TO JEDEC STANDARDS MO-229-WEED
Figure 52. 8-Lead Lead Frame Chip Scale Package [LFCSP_WD]
3 mm × 3 mm Body, Very Very Thin, Dual Lead
(CP-8-13)
Dimensions shown in millimeters
5.00 (0.1968)
4.80 (0.1890)
1
5
6.20 (0.2441)
5.80 (0.2284)
4
1.27 (0.0500)
BSC
0.25 (0.0098)
0.10 (0.0040)
COPLANARITY
0.10
SEATING
PLANE
0.50 (0.0196)
0.25 (0.0099)
1.75 (0.0688)
1.35 (0.0532)
0.51 (0.0201)
0.31 (0.0122)
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-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 53. 8-Lead Standard Small Outline Package [SOIC_N]
Narrow Body
(R-8)
Dimensions shown in millimeters and (inches)
Rev. F | Page 17 of 20
012407-A
8
4.00 (0.1574)
3.80 (0.1497)
ADA4627-1/ADA4637-1
Data Sheet
ORDERING GUIDE
Model 1
ADA4627-1ACPZ-R2
ADA4627-1ACPZ-RL
ADA4627-1ACPZ-R7
ADA4627-1ARZ
ADA4627-1ARZ-RL
ADA4627-1ARZ-R7
ADA4627-1BRZ
ADA4627-1BRZ-R7
ADA4627-1BRZ-RL
ADA4637-1ACPZ-R2
ADA4637-1ACPZ-RL
ADA4637-1ACPZ-R7
ADA4637-1ARZ
ADA4637-1ARZ-RL
ADA4637-1ARZ-R7
ADA4637-1BRZ
ADA4637-1BRZ-R7
ADA4637-1BRZ-RL
1
Temperature Range
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
Package Description
8-Lead LFCSP_WD
8-Lead LFCSP_WD
8-Lead LFCSP_WD
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead LFCSP_WD
8-Lead LFCSP_WD
8-Lead LFCSP_WD
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
Z = RoHS Compliant Part.
Rev. F | Page 18 of 20
Package Option
CP-8-13
CP-8-13
CP-8-13
R-8
R-8
R-8
R-8
R-8
R-8
CP-8-13
CP-8-13
CP-8-13
R-8
R-8
R-8
R-8
R-8
R-8
Branding
A29
A29
A29
A2S
A2S
A2S
Data Sheet
ADA4627-1/ADA4637-1
NOTES
Rev. F | Page 19 of 20
ADA4627-1/ADA4637-1
Data Sheet
NOTES
©2009–2015 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D07559-0-6/15(F)
Rev. F | Page 20 of 20
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