ADA4665-2ARZ-R7 [ADI]
16 V, 1 MHz, CMOS Rail-to-Rail Input/Output Operational Amplifier; 16 V ， 1 MHz时， CMOS轨到轨输入/输出运算放大器
| 型号： | ADA4665-2ARZ-R7 |
| 厂家： | 
ADI |
| 描述： | 16 V, 1 MHz, CMOS Rail-to-Rail Input/Output Operational Amplifier |
| 文件： | 总20页 (文件大小：697K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
16 V, 1 MHz, CMOS Rail-to-Rail
Input/Output Operational Amplifier
ADA4665-2
PIN CONFIGURATIONS
FEATURES
Lower power at high voltage: 290 μA per amplifier typical
Low input bias current: 1 pA maximum
Wide bandwidth: 1.2 MHz typical
Slew rate: 1 V/μs typical
OUT A
–IN A
+IN A
V–
1
2
3
4
8
7
6
5
V+
ADA4665-2
TOP VIEW
(Not to Scale)
OUT B
–IN B
+IN B
Offset voltage drift: 3 μV/°C typical
Single-supply operation: 5 V to 16 V
Dual-supply operation: 2.5 V to 8 V
Unity gain stable
Figure 1. 8-Lead SOIC
OUT A
–IN A
+IN A
V–
1
2
3
4
8
7
6
5
V+
ADA4665-2
OUT B
–IN B
+IN B
APPLICATIONS
TOP VIEW
(Not to Scale)
Portable systems
High density power budget systems
Medical equipment
Physiological measurement
Precision references
Multipole filters
Figure 2. 8-Lead MSOP
Sensors
Transimpedance amplifiers
Buffer/level shifting
GENERAL DESCRIPTION
The ADA4665-2 is a rail-to-rail input/output dual amplifier
optimized for lower power budget designs. The ADA4665-2
offers a low supply current of 400 μA maximum per amplifier
at 25°C and 600 μA maximum per amplifier over the extended
industrial temperature range. This feature makes the ADA4665-2
well suited for low power applications. In addition, the ADA4665-2
has a very low bias current of 1 pA maximum, low offset voltage
drift of 3 μV/°C, and bandwidth of 1.2 MHz. The combination of
these features, together with a wide supply voltage range from
5 V to 16 V, allows the device to be used in a wide variety of
other applications, including process control, instrumentation
equipment, buffering, and sensor front ends. Furthermore, its
rail-to-rail input and output swing adds to its versatility. The
ADA4665-2 is specified from −40°C to +125°C and is available
in standard SOIC and MSOP packages.
Table 1. Low Cost Rail-to-Rail Input/Output Op Amps
Supply
Single
Dual
5 V
16 V
AD8541
AD8542
AD8544
ADA4665-2
Quad
Table 2. Other Rail-to-Rail Input/Output Op Amps
Supply
Single
Dual
5 V
16 V
36 V
AD8603
AD8607
AD8609
AD8663
AD8667
AD8669
ADA4091-2
Quad
Rev. 0
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. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registeredtrademarks arethe property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.461.3113
www.analog.com
©2009 Analog Devices, Inc. All rights reserved.
ADA4665-2
TABLE OF CONTENTS
Features .............................................................................................. 1
Thermal Resistance.......................................................................5
ESD Caution...................................................................................5
Typical Performance Characteristics ..............................................6
Applications Information.............................................................. 15
Rail-to-Rail Input Operation.................................................... 15
Current Shunt Sensor ................................................................ 15
Active Filters ............................................................................... 15
Outline Dimensions....................................................................... 17
Ordering Guide .......................................................................... 17
Applications....................................................................................... 1
Pin Configurations ........................................................................... 1
General Description......................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Electrical Characteristics—16 V Operation ............................. 3
Electrical Characteristics—5 V Operation................................ 4
Absolute Maximum Ratings............................................................ 5
REVISION HISTORY
1/09—Revision 0: Initial Version
Rev. 0 | Page 2 of 20
ADA4665-2
SPECIFICATIONS
ELECTRICAL CHARACTERISTICS—16 V OPERATION
VSY = 16 V, VCM = VSY/2, TA = 25°C, unless otherwise noted.
Table 3.
Parameter
Symbol
Test Conditions/Comments
Min
Typ
Max
Unit
INPUT CHARACTERISTICS
Offset Voltage
VOS
VCM = 16 V
1
1
4
6
9
mV
mV
mV
μV/°C
pA
pA
pA
pA
V
dB
dB
dB
dB
VCM = 0 V to 16 V
−40°C ≤ TA ≤ +125°C
−40°C ≤ TA ≤ +125°C
Offset Voltage Drift
Input Bias Current
∆VOS/∆T
IB
3
0.1
1
200
1
40
16
−40°C ≤ TA ≤ +125°C
Input Offset Current
IOS
0.1
−40°C ≤ TA ≤ +125°C
−40°C ≤ TA ≤ +125°C
VCM = 0 V to 16 V
−40°C ≤ TA ≤ +125°C
RL = 10 kΩ, VO = 0.5 V to 15 V
−40°C ≤ TA ≤ +125°C
Input Voltage Range
Common-Mode Rejection Ratio
0
CMRR
AVO
55
50
85
75
75
Large Signal Voltage Gain
100
Input Resistance
RIN
CINDM
CINCM
4
2
7
GΩ
pF
pF
Input Capacitance, Differential Mode
Input Capacitance, Common Mode
OUTPUT CHARACTERISTICS
Output Voltage High
VOH
RL = 100 kΩ to VCM
−40°C ≤ TA ≤ +125°C
RL = 10 kΩ to VCM
−40°C ≤ TA ≤ +125°C
RL = 100 kΩ to VCM
−40°C ≤ TA ≤ +125°C
RL = 10 kΩ to VCM
15.95
15.9
15.9
15.8
15.99
15.95
4
V
V
V
V
mV
mV
mV
mV
mA
Ω
Output Voltage Low
VOL
7.5
15
75
40
−40°C ≤ TA ≤ +125°C
150
Short-Circuit Current
Closed-Loop Output Impedance
POWER SUPPLY
ISC
ZOUT
30
f = 100 kHz, AV = 1
100
Power Supply Rejection Ratio
PSRR
ISY
VSY = 5 V to 16 V
−40°C ≤ TA ≤ +125°C
IO = 0 mA
70
65
95
dB
dB
μA
μA
Supply Current per Amplifier
290
400
600
−40°C ≤ TA ≤ +125°C
DYNAMIC PERFORMANCE
Slew Rate
Settling Time to 0.1%
Gain Bandwidth Product
Phase Margin
SR
tS
GBP
ΦM
RL = 10 kΩ, CL = 50 pF, AV = 1
VIN = 1 V step, RL = 2 kΩ, CL = 50 pF
RL = 10 kΩ, CL = 50 pF, AV = 1
RL = 10 kΩ, CL = 50 pF, AV = 1
1
V/μs
μs
MHz
Degrees
6.5
1.2
50
NOISE PERFORMANCE
Voltage Noise
Voltage Noise Density
en p-p
en
f = 0.1 Hz to 10 Hz
f = 1 kHz
f = 10 kHz
3
μV p-p
nV/√Hz
nV/√Hz
fA/√Hz
32
27
50
Current Noise Density
in
f = 1 kHz
Rev. 0 | Page 3 of 20
ADA4665-2
ELECTRICAL CHARACTERISTICS—5 V OPERATION
VSY = 5 V, VCM = VSY/2, TA = 25°C, unless otherwise noted.
Table 4.
Parameter
Symbol
Test Conditions/Comments
Min
Typ
Max
Unit
INPUT CHARACTERISTICS
Offset Voltage
VOS
VCM = 5 V
1
1
4
6
9
mV
mV
mV
μV/°C
pA
pA
pA
pA
V
dB
dB
dB
dB
VCM = 0 V to 5 V
−40°C ≤ TA ≤ +125°C
−40°C ≤ TA ≤ +125°C
Offset Voltage Drift
Input Bias Current
∆VOS/∆T
IB
3
0.1
1
100
1
10
5
−40°C ≤ TA ≤ +125°C
Input Offset Current
IOS
0.1
−40°C ≤ TA ≤ +125°C
−40°C ≤ TA ≤ +125°C
VCM = 0 V to 5 V
−40°C ≤ TA ≤ +125°C
RL = 10 kΩ, VO = 0.5 V to 4.5 V
−40°C ≤ TA ≤ +125°C
Input Voltage Range
Common-Mode Rejection Ratio
0
CMRR
AVO
55
50
85
75
75
Large Signal Voltage Gain
100
Input Resistance
RIN
CINDM
CINCM
1
2
7
GΩ
pF
pF
Input Capacitance, Differential Mode
Input Capacitance, Common Mode
OUTPUT CHARACTERISTICS
Output Voltage High
VOH
RL = 100 kΩ to VCM
−40°C ≤ TA ≤ +125°C
RL = 10 kΩ to VCM
−40°C ≤ TA ≤ +125°C
RL = 100 kΩ to VCM
−40°C ≤ TA ≤ +125°C
RL = 10 kΩ to VCM
4.95
4.9
4.9
4.99
4.96
3
V
V
V
V
mV
mV
mV
mV
mA
Ω
4.8
Output Voltage Low
VOL
5
10
50
100
30
−40°C ≤ TA ≤ +125°C
Short-Circuit Current
Closed-Loop Output Impedance
POWER SUPPLY
ISC
ZOUT
8
f = 100 kHz, AV = 1
100
Power Supply Rejection Ratio
PSRR
ISY
VSY = 5 V to 16 V
−40°C ≤ TA ≤ +125°C
IO = 0 mA
70
65
95
dB
dB
μA
μA
Supply Current per Amplifier
270
350
600
−40°C ≤ TA ≤ +125°C
DYNAMIC PERFORMANCE
Slew Rate
Settling Time to 0.1%
Gain Bandwidth Product
Phase Margin
SR
tS
GBP
ΦM
RL = 10 kΩ, CL = 50 pF, AV = 1
VIN = 1 V step, RL = 2 kΩ, CL = 50 pF
RL = 10 kΩ, CL = 50 pF, AV = 1
RL = 10 kΩ, CL = 50 pF, AV = 1
1
V/μs
μs
MHz
Degrees
6.5
1.2
50
NOISE PERFORMANCE
Voltage Noise
Voltage Noise Density
en p-p
en
f = 0.1 Hz to 10 Hz
f = 1 kHz
f = 10 kHz
3
μV p-p
nV/√Hz
nV/√Hz
fA/√Hz
32
27
50
Current Noise Density
in
f = 1 kHz
Rev. 0 | Page 4 of 20
ADA4665-2
ABSOLUTE MAXIMUM RATINGS
Table 5.
THERMAL RESISTANCE
θJA is specified for the worst-case conditions, that is, a device
soldered in a circuit board for surface-mount packages. This
value was measured using a 4-layer JEDEC standard printed
circuit board.
Parameter
Rating
Supply Voltage
Input Voltage1
Input Current
Differential Input Voltage
Output Short-Circuit Duration to GND Indefinite
Storage Temperature Range
Operating Temperature Range
Junction Temperature Range
16.5 V
GND − 0.3 V to VSY + 0.3 V
10 mA
VSY
Table 6. Thermal Resistance
Package Type
θJA
θJC
43
52
Unit
°C/W
°C/W
−65°C to +150°C
−40°C to +125°C
−65°C to +150°C
8-Lead SOIC_N (R-8)
8-Lead MSOP (RM-8)
158
186
Lead Temperature (Soldering, 60 sec) 300°C
ESD CAUTION
1 The input pins have clamp diodes to the power supply pins.
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 indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
Rev. 0 | Page 5 of 20
ADA4665-2
TYPICAL PERFORMANCE CHARACTERISTICS
TA = 25°C, unless otherwise noted.
70
70
60
50
40
V
V
= 5V
= V /2
SY
SY
V
V
= 16V
= V /2
SY
SY
CM
CM
60
50
40
30
20
10
30
20
10
0
0
–6 –5 –4 –3 –2 –1
0
1
2
3
4
5
6
10
5
–6 –5 –4 –3 –2 –1
0
1
2
3
4
5
6
10
16
V
(mV)
V
(mV)
OS
OS
Figure 3. Input Offset Voltage Distribution
Figure 6. Input Offset Voltage Distribution
10
10
V
= 16V
V
= 5V
SY
–40°C ≤ T ≤ +125°C
SY
–40°C ≤ T ≤ +125°C
9
8
7
6
5
4
3
2
1
0
9
8
7
6
5
4
3
2
1
0
A
A
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
TCV (µV/°C)
OS
TCV (µV/°C)
OS
Figure 4. Input Offset Voltage Drift Distribution
Figure 7. Input Offset Voltage Drift Distribution
5
5
4
V
= 5V
V
= 16V
SY
SY
4
3
3
2
2
1
1
0
0
–1
–2
–3
–4
–1
–2
–3
–4
0
1
2
3
4
0
2
4
6
8
10
12
14
V
(V)
V
(V)
CM
CM
Figure 5. Input Offset Voltage vs. Common-Mode Voltage
Figure 8. Input Offset Voltage vs. Common-Mode Voltage
Rev. 0 | Page 6 of 20
ADA4665-2
TA = 25°C, unless otherwise noted.
1k
1k
100
10
V
= 5V
SY
V
= 16V
I
I
+
–
SY
B
B
I
I
+
–
B
B
100
10
1
1
0.1
0.01
0.1
0.01
0.001
0.001
25
50
75
100
125
25
50
75
100
125
TEMPERATURE (°C)
TEMPERATURE (°C)
Figure 9. Input Bias Current vs. Temperature
Figure 12. Input Bias Current vs. Temperature
1k
1k
V
= 5V
V
= 16V
SY
SY
100
10
1
100
10
1
125°C
105°C
125°C
105°C
85°C
25°C
85°C
25°C
0.1
0.01
0.1
0.01
0.001
0.001
0.0001
0.0001
0
1
2
3
4
5
0
2
4
6
8
10
12
14
16
V
(V)
V
(V)
CM
CM
Figure 10. Input Bias Current vs. Input Common-Mode Voltage
Figure 13. Input Bias Current vs. Input Common-Mode Voltage
10k
10k
V
= 5V
V
= 16V
SY
SY
1k
100
10
1k
100
10
1
0.1
–40°C
+25°C
+85°C
+125°C
–40°C
+25°C
+85°C
+125°C
1
0.1
0.001
0.01
0.001
0.01
0.1
1
10
100
0.01
0.1
1
10
100
LOAD CURRENT (mA)
LOAD CURRENT (mA)
Figure 11. Output Voltage (VOH) to Supply Rail vs. Load Current
Figure 14. Output Voltage (VOH) to Supply Rail vs. Load Current
Rev. 0 | Page 7 of 20
ADA4665-2
TA = 25°C, unless otherwise noted.
10k
10k
1k
V
= 16V
V
= 5V
SY
SY
1k
100
10
100
10
1
–40°C
+25°C
+85°C
+125°C
–40°C
+25°C
+85°C
+125°C
1
0.1
0.001
0.1
0.001
0.01
0.1
1
10
100
0.01
0.1
1
10
100
LOAD CURRENT (mA)
LOAD CURRENT (mA)
Figure 15. Output Voltage (VOL) to Supply Rail vs. Load Current
Figure 18. Output Voltage (VOL) to Supply Rail vs. Load Current
5.00
4.99
16.00
15.99
R
= 100kΩ
R
= 100kΩ
L
L
15.98
15.97
15.96
15.95
15.94
15.93
15.92
15.91
15.90
4.98
4.97
4.96
4.95
R
= 10kΩ
L
R
= 10kΩ
L
4.94
4.93
4.92
V
= 5V
SY
V
= 16V
SY
–50
–25
0
25
50
75
100
125
–50
–25
0
25
50
75
100
125
TEMPERATURE (°C)
TEMPERATURE (°C)
Figure 16. Output Voltage (VOH) vs. Temperature
Figure 19. Output Voltage (VOH) vs. Temperature
60
50
40
30
20
10
0
60
50
40
30
20
10
0
V
= 5V
V
= 16V
SY
SY
R
= 10kΩ
L
R
= 10kΩ
L
R
= 100kΩ
L
R
= 100kΩ
L
–50
–25
0
25
50
75
100
125
–50
–25
0
25
50
75
100
125
TEMPERATURE (°C)
TEMPERATURE (°C)
Figure 17. Output Voltage (VOL) vs. Temperature
Figure 20. Output Voltage (VOL) vs. Temperature
Rev. 0 | Page 8 of 20
ADA4665-2
TA = 25°C, unless otherwise noted.
180
135
90
45
0
180
80
80
60
V
R
C
= 5V
= 10kΩ
= 50pF
V
R
C
= 16V
= 10kΩ
= 50pF
SY
SY
L
L
L
L
135
60
PHASE
PHASE
GAIN
40
20
40
20
90
45
0
GAIN
0
0
–20
–40
–20
–40
–45
–90
–45
–90
1k
10k
100k
FREQUENCY (Hz)
1M
10M
1k
10k
100k
FREQUENCY (Hz)
1M
10M
Figure 21. Open-Loop Gain and Phase vs. Frequency
Figure 24. Open-Loop Gain and Phase vs. Frequency
50
40
50
40
V
R
= 5V
= 10kΩ
V
R
= 16V
= 10kΩ
A
= 100
= 10
A
= 100
= 10
SY
SY
V
V
V
L
L
30
30
A
A
V
20
20
10
10
A
= 1
A
= 1
V
V
0
0
–10
–20
–30
–40
–50
–10
–20
–30
–40
–50
100
1k
10k
100k
1M
10M
100M
100
1k
10k
100k
1M
10M
100M
FREQUENCY (Hz)
FREQUENCY (Hz)
Figure 22. Closed-Loop Gain vs. Frequency
Figure 25. Closed-Loop Gain vs. Frequency
1k
1k
V
= 5V
V
= 16V
SY
SY
100
100
10
A
= 100
A
= 100
V
V
10
1
A
= 10
V
A = 10
V
1
A
= 1
V
A
= 1
V
0.1
0.1
0.01
0.01
10
100
1k
10k
100k
1M
10M
10
100
1k
10k
100k
1M
10M
FREQUENCY (Hz)
FREQUENCY (Hz)
Figure 23. Output Impedance vs. Frequency
Figure 26. Output Impedance vs. Frequency
Rev. 0 | Page 9 of 20
ADA4665-2
TA = 25°C, unless otherwise noted.
100
100
V
= 5V
V
= 16V
SY
SY
90
80
90
80
70
60
50
40
70
60
50
40
100
1k
10k
100k
1M
100
1k
10k
100k
1M
FREQUENCY (Hz)
FREQUENCY (Hz)
Figure 27. CMRR vs. Frequency
Figure 30. CMRR vs. Frequency
120
120
100
80
V
= 5V
V
= 16V
SY
SY
100
80
60
60
40
20
0
40
20
0
PSRR+
PSRR–
PSRR+
PSRR–
–20
100
–20
100
1k
10k
100k
1M
10M
1k
10k
100k
1M
10M
FREQUENCY (Hz)
FREQUENCY (Hz)
Figure 28. PSRR vs. Frequency
Figure 31. PSRR vs. Frequency
80
80
V
V
R
= 16V
= 100mV p-p
= 10kΩ
V
V
R
= 5V
= 100mV p-p
= 10kΩ
SY
IN
SY
IN
70
60
50
40
70
60
50
40
L
L
OS+
OS–
OS+
OS–
30
20
10
0
30
20
10
0
10
100
CAPACITANCE (pF)
1k
10
100
CAPACITANCE (pF)
1k
Figure 32. Small Signal Overshoot vs. Load Capacitance
Figure 29. Small Signal Overshoot vs. Load Capacitance
Rev. 0 | Page 10 of 20
ADA4665-2
TA = 25°C, unless otherwise noted.
V
R
C
= 5V
= 2kΩ
= 10pF
V
R
C
= 16V
= 2kΩ
= 10pF
SY
SY
L
L
L
L
TIME (100µs/DIV)
TIME (100µs/DIV)
Figure 33. Large Signal Transient Response
Figure 36. Large Signal Transient Response
V
R
C
= 5V
= 2kΩ
= 10pF
V
R
C
= 16V
= 2kΩ
= 10pF
SY
SY
L
L
L
L
TIME (100µs/DIV)
TIME (100µs/DIV)
Figure 34. Small Signal Transient Response
Figure 37. Small Signal Transient Response
50
50
V
= ±8V
V
= ±2.5V
SY
SY
0
0
INPUT
INPUT
–50
–50
–100
–100
3
2
10
5
0
1
0
OUTPUT
OUTPUT
–5
–1
TIME (20µs/DIV)
TIME (20µs/DIV)
Figure 35. Positive Overload Recovery
Figure 38. Positive Overload Recovery
Rev. 0 | Page 11 of 20
ADA4665-2
TA = 25°C, unless otherwise noted.
150
150
V
= ±2.5V
V
= ±8V
SY
SY
100
50
100
50
INPUT
INPUT
0
0
OUTPUT
0
OUTPUT
0
–1
–2
–3
–5
–10
TIME (20µs/DIV)
TIME (20µs/DIV)
Figure 39. Negative Overload Recovery
Figure 42. Negative Overload Recovery
V
R
C
= 16V
= 2kΩ
= 50pF
SY
V
R
C
= 5V
= 2kΩ
= 50pF
SY
L
L
L
L
INPUT
INPUT
OUTPUT
OUTPUT
+5mV
+5mV
ERROR
BAND
ERROR
BAND
0
0
–5mV
–5mV
TIME (2µs/DIV)
TIME (2µs/DIV)
Figure 40. Negative Settling Time to 0.1%
Figure 43. Negative Settling Time to 0.1%
INPUT
INPUT
V
= 16V
V
= 5V
SY
SY
R
C
= 2kΩ
= 50pF
R
C
= 2kΩ
= 50pF
L
L
L
L
ERROR
BAND
OUTPUT
OUTPUT
+5mV
+5mV
ERROR
BAND
0
0
–5mV
–5mV
TIME (2µs/DIV)
TIME (2µs/DIV)
Figure 41. Positive Settling Time to 0.1%
Figure 44. Positive Settling Time to 0.1%
Rev. 0 | Page 12 of 20
ADA4665-2
TA = 25°C, unless otherwise noted.
100
100
V
= 5V
V
= 16V
SY
SY
10
100
10
100
1k
10k
100k
1k
10k
100k
FREQUENCY (Hz)
FREQUENCY (Hz)
Figure 45. Voltage Noise Density vs. Frequency
Figure 48. Voltage Noise Density vs. Frequency
V
= 5V
V
= 16V
SY
SY
TIME (2s/DIV)
TIME (2s/DIV)
Figure 46. 0.1 Hz to 10 Hz Noise
Figure 49. 0.1 Hz to 10 Hz Noise
900
900
800
700
600
500
800
700
600
500
400
300
200
100
0
+125°C
+85°C
+25°C
–40°C
V
= 16V
SY
V
= 5V
SY
400
300
0
2
4
6
8
10
12
14
16
–50
–25
0
25
50
75
100
125
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
Figure 47. Supply Current vs. Supply Voltage
Figure 50. Supply Current vs. Temperature
Rev. 0 | Page 13 of 20
ADA4665-2
TA = 25°C, unless otherwise noted.
0
0
V
R
A
= 5V
= 10kΩ
= –100
V
R
A
= 16V
= 10kΩ
= –100
100kΩ
SY
100kΩ
SY
L
V
L
V
1kΩ
1kΩ
–20
–40
–20
–40
–60
–60
–80
–80
–100
–120
–140
–160
–100
–120
–140
–160
V
V
V
= 1V p-p
= 5V p-p
= 15V p-p
IN
IN
IN
V
V
= 1V p-p
= 4V p-p
IN
IN
100
1k
10k
100k
100
1k
10k
100k
FREQUENCY (Hz)
FREQUENCY (Hz)
Figure 51. Channel Separation vs. Frequency
Figure 53. Channel Separation vs. Frequency
1
1
V
R
A
= 16V
= 10kΩ
= 1
V
R
A
= 5V
= 10kΩ
= 1
SY
SY
L
V
L
V
0.1
0.1
0.01
0.001
0.01
V
V
V
= 1V p-p
= 5V p-p
= 15V p-p
IN
IN
IN
V
V
= 1V p-p
= 4V p-p
IN
IN
0.001
10
100
1k
10k
100k
10
100
1k
10k
100k
FREQUENCY (Hz)
FREQUENCY (Hz)
Figure 54. THD + Noise vs. Frequency
Figure 52. THD + Noise vs. Frequency
Rev. 0 | Page 14 of 20
ADA4665-2
APPLICATIONS INFORMATION
I
RAIL-TO-RAIL INPUT OPERATION
16V
R
0.1Ω
S
R
L
SUPPLY
The ADA4665-2 is a unity-gain stable CMOS operational
amplifier designed with rail-to-rail input/output swing
capability to optimize performance. The rail-to-rail input
feature is vital to maintain the wide dynamic input voltage
range and to maximize signal swing to both supply rails. For
example, the rail-to-rail input feature is extremely useful in
buffer applications where the input voltage must cover both
the supply rails.
I
R2
1MΩ
R1
10kΩ
V
*
OUT
16V
1/2
ADA4665-2
R4
1MΩ
R3
10kΩ
The input stage has two input differential pairs, nMOS and
pMOS. When the input common-mode voltage is at the low
end of the input voltage range, the pMOS input differential pair
is active and amplifies the input signal. As the input common-
mode voltage is slowly increased, the pMOS differential pair
gradually turns off while the nMOS input differential pair turns
on. This transition is inherent to all rail-to-rail input amplifiers
that use the dual differential pairs topology. For the ADA4665-2,
this transition occurs approximately 1 V away from the positive
rail and results in a change in offset voltage due to the different
offset voltages of the differential pairs (see Figure 5 and Figure 8).
*V
= AMPLIFIER GAIN × VOLTAGE ACROSS R
S
OUT
= 100 × R × I
S
= 10 × I
Figure 55. Low-Side Current Sensing Circuit
R
S
0.1Ω
I
16V
SUPPLY
R
L
I
R4
R3
1MΩ
10kΩ
16V
1/2
V
*
OUT
CURRENT SHUNT SENSOR
ADA4665-2
R2
1MΩ
R1
10kΩ
Many applications require the sensing of signals near the
positive or the negative rails. Current shunt sensors are one
such application and are mostly used for feedback control
systems. They are also used in a variety of other applications,
including power metering, battery fuel gauging, and feedback
controls in electrical power steering. In such applications, it is
desirable to use a shunt with very low resistance to minimize
the series voltage drop. This not only minimizes wasted power,
but also allows the measurement of high currents while saving
power. The ADA4665-2 provides a low cost solution for
implementing current shunt sensors.
*V
= AMPLIFIER GAIN × VOLTAGE ACROSS R
S
OUT
= 100 × R × I
= 10 × I
S
Figure 56. High-Side Current Sensing Circuit
ACTIVE FILTERS
The ADA4665-2 is well suited for active filter designs. An active
filter requires an op amp with a unity-gain bandwidth at least
100 times greater than the product of the corner frequency, fc,
and the quality factor, Q. An example of an active filter is the
Sallen-Key, one of the most widely used filter topologies. This
topology gives the user the flexibility of implementing either
a low-pass or a high-pass filter by simply interchanging the
resistors and capacitors. To achieve the desired performance,
1% or better component tolerances are usually required.
Figure 55 shows a low-side current sensing circuit, and Figure 56
shows a high-side current sensing circuit using the ADA4665-2.
A typical shunt resistor of 0.1 Ω is used. In these circuits, the
difference amplifier amplifies the voltage drop across the shunt
resistor by a factor of 100. For true difference amplification,
matching of the resistor ratio is very important, where R1/R2 =
R3/R4. The rail-to-rail feature of the ADA4665-2 allows the
output of the op amp to almost reach 16 V (the power supply of
the op amp). This allows the current shunt sensor to sense up to
approximately 1.6 A of current.
Figure 57 shows a two-pole low-pass filter. It is configured as a
unity-gain filter with cutoff frequency at 10 kHz. Resistor and
capacitor values are chosen to give a quality factor, Q, of 1/√2
for a Butterworth filter, which has maximally flat pass-band
frequency response. Figure 58 shows the frequency response of
the low-pass Sallen-Key filter. The response falls off at a rate of
40 dB per decade after the cutoff frequency of 10 kHz.
Rev. 0 | Page 15 of 20
ADA4665-2
C1
1nF
R1
22.5kΩ
Figure 59 shows a two-pole high-pass filter, with cutoff frequency
at 10 kHz and quality factor, Q, of 1/√2.
V
IN
+V
R2
SY
C1
0.5nF
R1
22.5kΩ
22.5kΩ
V
IN
1/2
V
OUT
C2
0.5nF
+V
SY
C2
0.5nF
ADA4665-2
–V
SY
1/2
V
OUT
R2
45kΩ
ADA4665-2
Figure 57. Two-Pole Low-Pass Filter
–V
SY
When R1 = R2 and C1 = 2C2, the values of Q and the cutoff
frequency are calculated as follows:
Figure 59. Two-Pole High-Pass Filter
When R2 = 2R1 and C1 = C2, the values of Q and the cutoff
frequency are calculated as follows:
R1R2C1C2
Q =
C2(R1+ R2)
R1R2C1C2
Q =
1
fc =
R1(C1+C2)
2π R1 R2 C1 C2
1
fc =
10
0
2π R1R2 C1C2
10
0
–10
–20
–10
–20
–30
–40
–50
–30
–40
–50
–60
–70
–80
–90
–100
–110
–120
–60
100
1k
10k
100k
1M
FREQUENCY (Hz)
Figure 58. Low-Pass Filter: Gain vs. Frequency
10
100
1k
10k
100k
1M
FREQUENCY (Hz)
Figure 60. High-Pass Filter: Gain vs. Frequency
Rev. 0 | Page 16 of 20
ADA4665-2
OUTLINE DIMENSIONS
5.00 (0.1968)
4.80 (0.1890)
8
1
5
4
6.20 (0.2441)
5.80 (0.2284)
4.00 (0.1574)
3.80 (0.1497)
0.50 (0.0196)
0.25 (0.0099)
1.27 (0.0500)
BSC
45°
1.75 (0.0688)
1.35 (0.0532)
0.25 (0.0098)
0.10 (0.0040)
8°
0°
0.51 (0.0201)
0.31 (0.0122)
COPLANARITY
0.10
1.27 (0.0500)
0.40 (0.0157)
0.25 (0.0098)
0.17 (0.0067)
SEATING
PLANE
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 61. 8-Lead Standard Small Outline Package [SOIC_N]
Narrow Body
(R-8)
Dimensions shown in millimeters and (inches)
3.20
3.00
2.80
8
1
5
4
5.15
4.90
4.65
3.20
3.00
2.80
PIN 1
0.65 BSC
0.95
0.85
0.75
1.10 MAX
0.80
0.60
0.40
8°
0°
0.15
0.00
0.38
0.22
0.23
0.08
SEATING
PLANE
COPLANARITY
0.10
COMPLIANT TO JEDEC STANDARDS MO-187-AA
Figure 62. 8-Lead Mini Small Outline Package [MSOP]
(RM-8)
Dimensions shown in millimeters
ORDERING GUIDE
Model
Temperature Range
Package Description
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead MSOP
Package Option
Branding
ADA4665-2ARZ1
ADA4665-2ARZ-RL1
ADA4665-2ARZ-R71
ADA4665-2ARMZ1
ADA4665-2ARMZ-R71
ADA4665-2ARMZ-RL1
−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
R-8
R-8
R-8
RM-8
RM-8
RM-8
A26
A26
A26
8-Lead MSOP
8-Lead MSOP
1 Z = RoHS Compliant Part.
Rev. 0 | Page 17 of 20
ADA4665-2
NOTES
Rev. 0 | Page 18 of 20
ADA4665-2
NOTES
Rev. 0 | Page 19 of 20
ADA4665-2
NOTES
©2009 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D07650-0-1/09(0)
Rev. 0 | Page 20 of 20
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