AD AD8603 Precision micropower, low noise cmos rail-to-rail input/output operational amplifier Datasheet

Precision Micropower, Low Noise CMOS
Rail-to-Rail Input/Output Operational Amplifiers
AD8603/AD8607/AD8609
PIN CONFIGURATIONS
V– 2
AD8603
+IN 3
–IN
–IN A 2
AD8607
+IN A 3
TOP VIEW
(Not to Scale)
V– 4
8
V+
7
OUT B
6
–IN B
5
+IN B
Figure 2. 8-Lead MSOP (RM Suffix)
–IN A 2
AD8607
8
V+
7
OUT B
6 –IN B
TOP VIEW
V– 4 (Not to Scale) 5 +IN B
+IN A 3
The AD8603/AD8607/AD8609 are single/dual/quad micropower rail-to-rail input and output amplifiers, respectively, that
feature very low offset voltage as well as low input voltage and
current noise.
These amplifiers use a patented trimming technique that
achieves superior precision without laser trimming. The parts
are fully specified to operate from 1.8 V to 5.0 V single supply
or from ±0.9 V to ±2.5 V dual supply. The combination of low
offsets, low noise, very low input bias currents, and low power
consumption make the AD8603/AD8607/AD8609 especially
useful in portable and loop-powered instrumentation.
The ability to swing rail-to-rail at both the input and output
enables designers to buffer CMOS ADCs, DACs, ASICs, and
other wide output swing devices in low power, single-supply
systems.
The AD8603 is available in a tiny 5-lead TSOT-23 package.
The AD8607 is available in 8-lead MSOP and 8-lead SOIC
packages. The AD8609 is available in 14-lead TSSOP and
14-lead SOIC packages.
04356-002
Figure 1. 5-Lead TSOT-23 (UJ Suffix)
OUT A 1
GENERAL DESCRIPTION
4
04356-003
Battery-powered instrumentation
Multipole filters
Sensors
Low power ASIC input or output amplifiers
V+
TOP VIEW
(Not to Scale)
OUT A 1
APPLICATIONS
5
04356-001
OUT 1
Figure 3. 8-Lead SOIC_N (R Suffix)
OUT A 1
14
OUT D
–IN A 2
13
–IN D
AD8609
12
+IN D
TOP VIEW
(Not to Scale)
11
V–
+IN B 5
10
+IN C
–IN B 6
9
–IN C
OUT B 7
8
OUT C
+IN A 3
V+ 4
04356-004
Low offset voltage: 50 μV max
Low input bias current: 1 pA max
Single-supply operation: 1.8 V to 5 V
Low noise: 22 nV/√Hz
Micropower: 50 μA max
Low distortion
No phase reversal
Unity gain stable
Figure 4. 14-Lead TSSOP (RU Suffix)
OUT A
1
–IN A
2
+IN A 3
V+ 4
+IN B 5
14 OUT D
13 –IN D
AD8609
12 +IN D
TOP VIEW
11 V–
(Not to Scale)
10 +IN C
–IN B
6
9
–IN C
OUT B
7
8
OUT C
04356-005
FEATURES
Figure 5. 14-Lead SOIC_N (R Suffix)
Rev. B
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
registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113
© 2005 Analog Devices, Inc. All rights reserved.
AD8603/AD8607/AD8609
TABLE OF CONTENTS
Specifications..................................................................................... 3
Driving Capacitive Loads.......................................................... 12
Absolute Maximum Ratings............................................................ 5
Proximity Sensors....................................................................... 13
ESD Caution.................................................................................. 5
Composite Amplifiers................................................................ 13
Typical Performance Characteristics ............................................. 6
Battery-Powered Applications .................................................. 14
Applications..................................................................................... 12
Photodiodes ................................................................................ 14
No Phase Reversal ...................................................................... 12
Outline Dimensions ....................................................................... 15
Input Overvoltage Protection ................................................... 12
Ordering Guide .......................................................................... 17
REVISION HISTORY
6/05—Rev. A to Rev. B
Updated Figure 49 .......................................................................... 15
Changes to Ordering Guide .......................................................... 17
10/03—Rev. 0 to Rev. A
Added AD8607 and AD8609 Parts ..................................Universal
Changes to Specifications ................................................................ 3
Changes to Figure 35...................................................................... 10
Added Figure 41.............................................................................. 11
8/03—Revision 0: Initial Version
Rev. B | Page 2 of 20
AD8603/AD8607/AD8609
SPECIFICATIONS
Electrical Characteristics @ VS = 5 V, VCM = VS/2, TA = 25°C, unless otherwise noted.
Table 1.
Parameter
INPUT CHARACTERISTICS
Offset Voltage
Symbol
Conditions
VOS
Offset Voltage Drift
Input Bias Current
∆VOS/∆T
IB
VS = 3.3 V @ VCM = 0.5 V and 2.8 V
–0.3 V < VCM < +5.2 V
–40°C < TA < +125°C, –0.3 V < VCM < +5.2 V
–40°C < TA < +125°C
Min
Typ
Max
Unit
12
40
50
300
700
4.5
1
50
500
0.5
50
250
+5.2
μV
μV
μV
μV/°C
pA
pA
pA
pA
pA
pA
V
dB
dB
1
0.2
–40°C < TA < +85°C
–40°C < TA < +125°C
Input Offset Current
IOS
0.1
–40°C < TA < +85°C
–40°C < TA < +125°C
Input Voltage Range
Common-Mode Rejection Ratio
IVR
CMRR
Large Signal Voltage Gain
AD8603
AD8607/AD8609
Input Capacitance
AVO
OUTPUT CHARACTERISTICS
Output Voltage High
Output Voltage Low
Output Current
Closed-Loop Output Impedance
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current/Amplifier
DYNAMIC PERFORMANCE
Slew Rate
Settling Time 0.1%
Gain Bandwidth Product
Phase Margin
NOISE PERFORMANCE
Peak-to-Peak Noise
Voltage Noise Density
Current Noise Density
Channel Separation
0 V < VCM < 5 V
–40°C < TA < +125°C
RL = 10 kΩ, 0.5 V <VO < 4.5 V
–0.3
85
80
400
250
1000
450
1.9
2.5
V/mV
V/mV
pF
pF
4.95
4.9
4.65
4.50
4.97
V
V
V
V
mV
mV
mV
mV
mA
Ω
CDIFF
CCM
VOH
VOL
IOUT
ZOUT
IL = 1 mA
–40°C to +125°C
IL = 10 mA
–40°C to +125°C
IL = 1 mA
–40°C to +125°C
IL = 10 mA
–40°C to +125°C
100
4.97
16
160
±80
36
f = 10 kHz, AV = 1
PSRR
ISY
1.8 V < VS < 5 V
VO = 0 V
–40°C <TA < +125°C
SR
tS
GBP
RL = 10 kΩ
G = ±1, 2 V Step
RL = 100 kΩ
RL = 10 kΩ
RL = 10 kΩ, RL = 100 kΩ
0.1
23
400
316
70
0.1 Hz to 10 Hz
f = 1 kHz
f = 10 kHz
f = 1 kHz
f = 10 kHz
f = 100 kHz
2.3
25
22
0.05
–115
–110
ØO
en p-p
en
in
Cs
Rev. B | Page 3 of 20
30
50
250
330
80
100
40
50
60
dB
μA
μA
V/μs
μs
kHz
kHz
Degrees
3.5
μV
nV/√Hz
nV/√Hz
pA/√Hz
dB
dB
AD8603/AD8607/AD8609
Electrical Characteristics @ VS = 1.8 V, VCM = VS/2, TA = 25°C, unless otherwise noted.
Table 2.
Parameter
INPUT CHARACTERISTICS
Offset Voltage
Symbol
Conditions
VOS
Offset Voltage Drift
Input Bias Current
∆VOS/∆T
IB
VS = 3.3 V @ VCM = 0.5 V and 2.8 V
–0.3 V < VCM < +1.8 V
–40°C < TA < +85°C, –0.3 V < VCM < +1.8 V
–40°C < TA < +125°C, –0.3 V < VCM < +1.7 V
–40°C < TA < +125°C
Min
Typ
Max
Unit
12
40
50
300
500
700
4.5
1
50
500
0.5
50
250
+1.8
μV
μV
μV
μV
μV/°C
pA
pA
pA
pA
pA
pA
V
dB
dB
1
0.2
–40°C < TA < +85°C
–40°C < TA < +125°C
Input Offset Current
IOS
0.1
–40°C < TA < +85°C
–40°C < TA < +125°C
Input Voltage Range
Common-Mode Rejection Ratio
IVR
CMRR
Large Signal Voltage Gain
AD8603
AD8607/AD8609
Input Capacitance
AVO
OUTPUT CHARACTERISTICS
Output Voltage High
Output Voltage Low
Output Current
Closed-Loop Output Impedance
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current/Amplifier
DYNAMIC PERFORMANCE
Slew Rate
Settling Time 0.1%
Gain Bandwidth Product
Phase Margin
NOISE PERFORMANCE
Peak-to-Peak Noise
Voltage Noise Density
0 V < VCM < 1.8 V
–40°C < TA < +85°C
RL = 10 kΩ, 0.5 V <VO < 4.5 V
–0.3
80
70
150
100
3000
2000
2.1
3.8
V/mV
V/mV
pF
pF
1.65
1.6
1.72
V
V
mV
mV
mA
Ω
CDIFF
CCM
VOH
VOL
IOUT
ZOUT
IL = 1 mA
–40°C to +125°C
IL = 1 mA
–40°C to +125°C
98
38
±7
36
f = 10 kHz, AV = 1
PSRR
ISY
1.8 V < VS < 5 V
VO = 0 V
–40°C < TA < +85°C
SR
tS
GBP
RL = 10 kΩ
G = ±1, 1 V Step
RL = 100 kΩ
RL = 10 kΩ
RL = 10 kΩ, RL = 100 kΩ
0.1
9.2
385
316
70
0.1 Hz to 10 Hz
f = 1 kHz
f = 10 kHz
f = 1 kHz
2.3
25
22
0.05
f = 10 kHz
f = 100 kHz
–115
–110
ØO
en p-p
en
Current Noise Density
in
Channel Separation
Cs
Rev. B | Page 4 of 20
60
80
80
100
40
50
60
dB
μA
μA
V/μs
μs
kHz
kHz
Degrees
3.5
μV
nV/√Hz
nV/√Hz
pA/√Hz
dB
dB
AD8603/AD8607/AD8609
ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter 1
Supply Voltage
Input Voltage
Differential Input Voltage
Output Short-Circuit Duration to GND
Storage Temperature Range
All Packages
Lead Temperature (Soldering, 60 sec)
Operating Temperature Range
Junction Temperature Range
All Packages
1
Table 4. Package Characteristics
Rating
6V
GND to VS
±6 V
Indefinite
Package Type
5-Lead TSOT-23 (UJ)
8-Lead MSOP (RM)
8-Lead SOIC_N (R)
14-Lead SOIC_N (R)
14-Lead TSSOP (RU)
–65°C to +150°C
300°C
–40°C to +125°C
–65°C to +150°C
Absolute maximum ratings apply at 25°C, unless otherwise noted.
1
θJA 1
207
210
158
120
180
θJC
61
45
43
36
35
Unit
°C/W
°C/W
°C/W
°C/W
°C/W
θJA is specified for the worst-case conditions, that is, θJA is specified for device
soldered in circuit board for surface-mount packages.
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.
ESD 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 this product 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. B | Page 5 of 20
AD8603/AD8607/AD8609
TYPICAL PERFORMANCE CHARACTERISTICS
2600
300
VS = 5V
TA = 25°C
VCM = 0V TO 5V
2400
2200
200
2000
150
1800
100
1600
50
1400
VOS (μV)
1200
1000
0
–50
–100
800
–150
600
400
–200
200
–250
–270 –210 –150 –90
–30 0 30
VOS (μV)
90
150
210
–300
0.0
04356-006
0
270
Figure 6. Input Offset Voltage Distribution
0.6
0.9
1.2
1.5 1.8
VCM (V)
(V)
2.1
2.4
2.7
3.0
3.3
Figure 9. Input Offset Voltage vs. Common-Mode Voltage
30
400
350
25
VS = ±2.5V
TA = –40°C TO +125°C
VCM = 0V
20
INPUT BIAS CURRENT (pA)
NUMBERS OF AMPLIFIERS
0.3
04356-009
NUMBER OF AMPLIFIERS
VS = 3.3V
TA = 25°C
250
15
10
VS = ±2.5V
300
250
200
150
100
5
0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0 4.4 4.8 5.2
TCVOS (μV/°C)
0
0
Figure 7. Input Offset Voltage Drift Distribution
OUTPUT VOLTAGE TO SUPPLY RAIL (mV)
150
100
50
0
–50
–100
–150
–200
–250
0.5
1.0
1.5
2.0
2.5
3.0
VCM (V)
3.5
4.0
4.5
5.0
125
VS = 5V
TA = 25°C
100
10
SINK
SOURCE
1
0.1
0.01
0.001
04356-008
VOS (μV)
100
1000
VS = 5V
TA = 25°C
200
–300
0.0
75
50
TEMPERATURE (°C)
Figure 10. Input Bias vs. Temperature
300
250
25
Figure 8. Input Offset Voltage vs. Common-Mode Voltage
0.01
0.1
LOAD CURRENT (mA)
1
Figure 11. Output Voltage to Supply Rail vs. Load Current
Rev. B | Page 6 of 20
10
04356-011
0
04356-007
0
04356-010
50
AD8603/AD8607/AD8609
1925
350
VS = 5V
TA = 25°C
1750
300
VS = ±2.5V, ±0.9V
1575
OUTPUT SWING (mV)
250
OUTPUT IMPEDANCE (Ω)
VDD – VOH @ 10mA LOAD
200
VOL @ 10mA LOAD
150
100
1400
1225
1050
A = 100
875
700
A = 10
A=1
525
VDD – VOH @ 1mA LOAD
5
–10
20
35
50
65
TEMPERATURE (°C)
80
95
110
125
175
100
Figure 12. Output Voltage Swing vs. Temperature
140
180
120
135
100
40
90
20
45
0
0
40
–45
–90
–60
–135
–20
–80
–180
–40
100k
FREQUENCY (Hz)
–225
10M
1M
–60
100
Figure 13. Open-Loop Gain and Phase vs. Frequency
140
VS = 5V
VIN = 4.9V p-p
T = 25°C
AV = 1
100
80
3.0
60
PSRR (dB)
3.5
2.5
2.0
40
20
1.5
0
1.0
–20
0.5
–40
0.1
1
FREQUENCY (kHz)
10
100
–60
04356-014
0.0
0.01
VS = ±2.5V
120
10
Figure 14. Closed-Loop Output Voltage Swing vs. Frequency
100
1k
FREQUENCY (Hz)
10k
Figure 17. PSRR vs. Frequency
Rev. B | Page 7 of 20
100k
04356-017
4.0
100k
1k
10k
FREQUENCY (Hz)
Figure 16. Common-Mode Rejection Ratio vs. Frequency
5.0
4.5
20
0
04356-013
10k
VS = ±2.5V
60
–20
–100
1k
100k
80
–40
OUTPUT SWING (V p-p)
OPEN-LOOP GAIN (dB)
60
225
CMRR (dB)
VS = ±2.5V
RL = 100kΩ
CL = 20pF
φ = 70.9°
80
10k
FREQUENCY (Hz)
Figure 15. Output Impedance vs. Frequency
PHASE (Degree)
100
1k
04356-015
350
VOL @ 1mA LOAD
04356-012
0
–40 –25
04356-016
50
AD8603/AD8607/AD8609
60
VS = 5V
VS = 5V, 1.8V
VOLTAGE NOISE (1μV/DIV)
40
OS–
30
20
OS+
0
10
100
LOAD CAPACITANCE (pF)
1000
TIME (1s/DIV)
Figure 18. Small Signal Overshoot vs. Load Capacitance
04356-021
10
04356-018
SMALL SIGNAL OVERSHOOT (%)
50
Figure 21. 0.1 Hz to 10 Hz Input Voltage Noise
60
55
VS = 5V
RL = 10kΩ
CL = 200pF
AV = 1
VS = ±2.5V
50
VOLTAGE (50mV/DIV)
SUPPLY CURRENT (μA)
45
40
35
30
25
20
15
10
–10
5
20
35
50
65
TEMPERATURE (°C)
80
95
110
125
TIME (4μs/DIV)
Figure 19. Supply Current vs. Temperature
04356-022
–25
04356-019
5
0
–40
Figure 22. Small Signal Transient
100
VS = 5V
RL = 10kΩ
CL = 200pF
AV = 1
TA = 25°C
90
VOLTAGE (1V/DIV)
70
60
50
40
30
20
0
0
1.0
2.0
3.0
SUPPLY VOLTAGE (V)
4.0
5.0
TIME (20μs/DIV)
Figure 20. Supply Current vs. Supply Voltage
Figure 23. Large Signal Transient
Rev. B | Page 8 of 20
04356-023
10
04356-020
SUPPLY CURRENT (μA)
80
176
VS = ±2.5V
RL = 10kΩ
AV = 100
VIN = 50mV
+2.5V
VS = ±2.5V
VOLTAGE NOISE DENSITY (nV/ Hz)
VOUT (V)
AD8603/AD8607/AD8609
0V
VIN (mV)
0V
–50mV
154
132
110
88
66
44
TIME (4μs/DIV))
(40μs/DIV)
0
0
Figure 24. Negative Overload Recovery
3
4
5
6
FREQUENCY (kHz)
7
8
10
9
Figure 27. Voltage Noise Density vs. Frequency
+2.5V
NUMBER OF AMPLIFIERS
VOUT (V)
2
800
750
VS = ±2.5V
RL = 10kΩ
AV = 100
VIN = 50mV
0V
0V
VIN (mV)
1
04356-027
04356-024
22
–50mV
VS = 1.8V
TA = 25°C
VCM = 0V to 1.8V
700
650
600
550
500
450
400
350
300
250
200
150
04356-025
50
0
–300 –240 –180 –120
TIME (4μs/DIV)
0
60
VOS (μV)
120
180
240
300
Figure 28. VOS Distribution
Figure 25. Positive Overload Recovery
300
168
VS = ±2.5V
VS = 1.8V
TA = 25°C
250
144
200
150
120
100
50
VOS (μV)
96
72
0
–50
–100
48
–150
–200
24
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
FREQUENCY (kHz)
0.8
0.9
1.0
–300
0
0.3
0.6
0.9
V
VCM
(V)
CM(V)
1.2
1.5
1.8
Figure 29. Input Offset Voltage vs. Common-Mode Voltage
Figure 26. Voltage Noise Density vs. Frequency
Rev. B | Page 9 of 20
04356-029
–250
0
04356-026
VOLTAGE NOISE DENSITY (nV/ Hz)
–60
04356-028
100
AD8603/AD8607/AD8609
10
OPEN-LOOP GAIN (dB)
60
SOURCE
SINK
1
0.1
0.01
0.001
0.01
0.1
LOAD CURRENT (mA)
10
1
90
20
45
0
0
–20
–45
–40
–90
–60
–135
–80
–180
–100
1
10
–225
10M
1M
140
90
120
VS = 1.8V
VS = 1.8V
80
100
70
80
VDD – VOH @ 1mA LOAD
60
VOL @ 1mA LOAD
40
40
20
30
0
20
–20
10
–40
0
–40 –25
–10
5
50
65
20
35
TEMPERATURE (°C)
80
95
110
125
–60
100
Figure 31. Output Voltage Swing vs. Temperature
1k
10k
FREQUENCY (Hz)
100k
04356-034
CMRR (dB)
60
50
04356-031
Figure 34. Common-Mode Rejection Ratio vs. Frequency
60
1.8
VS = 1.8V
TA = 25°C
AV = 1
OUTPUT SWING (V p-p)
1.5
40
30
OS–
20
VS = 1.8V
VIN = 1.7V p-p
T = 25°C
AV = 1
1.2
0.9
0.6
OS+
10
100
LOAD CAPACITANCE (pF)
1000
04356-032
0
10
0.3
0.0
0.01
0.1
1
FREQUENCY (kHz)
10
100
Figure 35. Closed-Loop Output Voltage Swing vs. Frequency
Figure 32. Small Signal Overshoot vs. Load Capacitance
Rev. B | Page 10 of 20
04356-035
OUTPUT SWING (mV)
100
FREQUENCY (Hz)
Figure 33. Open-Loop Gain and Phase vs. Frequency
100
SMALL SIGNAL OVERSHOOT (%)
135
40
Figure 30. Output Voltage to Supply Rail vs. Load Current
50
180
PHASE (Degree)
100
225
VS = ±0.9V
RL = 100kΩ
CL = 20pF
φ = 70°
80
04356-033
100
VS = 1.8V
TA = 25°C
04356-030
OUTPUT VOLTAGE TO SUPPLY RAIL (mV)
1000
AD8603/AD8607/AD8609
176
VS = ±0.9V
VS = 1.8V
RL = 10kΩ
CL = 200pF
AV = 1
110
88
66
44
22
0
04356-036
TIME (4μs/DIV)
132
0
1
2
3
4
5
6
FREQUENCY (kHz)
7
8
9
10
04356-039
VOLTAGE (50mV/DIV)
VOLTAGE NOISE DENSITY (nV/ Hz)
154
Figure 39. Voltage Noise Density
Figure 36. Small Signal Transient
0
VS = ±2.5V, ±0.9V
VS = 1.8V
RL = 10kΩ
CL = 200pF
AV = 1
VOLTAGE (500mV/DIV)
CHANNEL SEPARATION (dB)
–20
–40
–60
–80
–100
04356-037
–140
100
TIME (20μs/DIV)
168
140
112
84
56
28
0
0.2
0.3
0.4
0.5
0.6
0.7
FREQUENCY (kHz)
0.8
0.9
1.0
04356-038
VOLTAGE NOISE DENSITY (nV/ Hz)
VS = ±0.9V
0.1
10k
FREQUENCY (Hz)
100k
Figure 40. Channel Separation
Figure 37. Large Signal Transient
0
1k
Figure 38. Voltage Noise Density
Rev. B | Page 11 of 20
1M
04356-040
–120
AD8603/AD8607/AD8609
APPLICATIONS
NO PHASE REVERSAL
The AD8603/AD8607/AD8609 do not exhibit phase inversion
even when the input voltage exceeds the maximum input
common-mode voltage. Phase reversal can cause permanent
damage to the amplifier, resulting in system lockups. The
AD8603/AD8607/AD8609 can handle voltages of up to 1 V
over the supply.
The use of the snubber circuit is usually recommended for unity
gain configurations. Higher gain configurations help improve
the stability of the circuit. Figure 44 shows the same output
response with the snubber in place.
VS = ±0.9V
VIN = 100mV
CL = 2nF
RL = 10kΩ
VS = ±2.5V
VIN = 6V p-p
AV = 1
RL = 10kΩ
VOLTAGE (1V/DIV)
VIN
04356-042
VOUT
TIME (4μs/DIV)
04356-041
Figure 42. Output Response to a 2 nF Capacitive Load, Without Snubber
VEE
Figure 41. No Phase Response
200mV +
–
If a voltage 1 V higher than the supplies is applied at either
input, the use of a limiting series resistor is recommended. If
both inputs are used, each one should be protected with a
series resistor.
RS
150Ω
VCC C
S
47pF
CL
04356-043
V–
V+
INPUT OVERVOLTAGE PROTECTION
Figure 43. Snubber Network
To ensure good protection, the current should be limited to a
maximum of 5 mA. The value of the limiting resistor can be
determined from the equation
VSY = ±0.9V
VIN = 100mV
CL = 2nF
RL = 10kΩ
RS = 150Ω
CS = 470pF
(VIN – VS)/(RS + 200 Ω) ≤ 5 mA
DRIVING CAPACITIVE LOADS
Although it is configured in positive unity gain (the worst case),
the AD8603 shows less than 20% overshoot. Simple additional
circuitry can eliminate ringing and overshoot.
04356-044
The AD8603/AD8607/AD8609 are capable of driving large
capacitive loads without oscillating. Figure 42 shows the output
of the AD8603/AD8607/AD8609 in response to a 100 mV input
signal, with a 2 nF capacitive load.
Figure 44. Output Response to a 2 nF Capacitive Load, With Snubber
One technique is the snubber network, which consists of a
series RC and a resistive load (see Figure 43). With the snubber
in place, the AD8603/AD8607/AD8609 are capable of driving
capacitive loads of 2 nF with no ringing and less than 3%
overshoot.
Rev. B | Page 12 of 20
AD8603/AD8607/AD8609
Optimum values for RS and CS are determined empirically;
Table 5 lists a few starting values.
COMPOSITE AMPLIFIERS
A composite amplifier can provide a very high gain in
applications where high closed-loop dc gains are needed. The
high gain achieved by the composite amplifier comes at the
expense of a loss in phase margin. Placing a small capacitor,
CF, in the feedback in parallel with R2 (Figure 45) improves the
phase margin. Picking CF = 50 pF yields a phase margin of
about 45° for the values shown in Figure 45.
Table 5. Optimum Values for the Snubber Network
CL (pF)
100~500
1500
1600~2000
RS (Ω)
500
100
400
CS (pF)
680
330
100
PROXIMITY SENSORS
Proximity sensors can be capacitive or inductive and are used in
a variety of applications. One of the most common applications
is liquid level sensing in tanks. This is particularly popular in
pharmaceutical environments where a tank must know when to
stop filling or mixing a given liquid. In aerospace applications,
these sensors detect the level of oxygen used to propel engines.
Whether in a combustible environment or not, capacitive
sensors generally use low voltage. The precision and low voltage
of the AD8603/AD8607/AD8609 make the parts an excellent
choice for such applications.
A composite amplifier can be used to optimize dc and ac
characteristics. Figure 46 shows an example using the AD8603
and the AD8541. This circuit offers many advantages. The
bandwidth is increased substantially, and the input offset
voltage and noise of the AD8541 become insignificant since
they are divided by the high gain of the AD8603.
The circuit of Figure 46 offers a high bandwidth (nearly double
that of the AD8603), a high output current, and a very low
power consumption of less than 100 μA.
R2
100kΩ
R2
R1
VEE
AD8603
VEE 99kΩ
1kΩ
1kΩ
V–
AD8603
VCC
VIN
U5
V+
V+
AD8541
V–
V+
R3
1kΩ
V+
R4
V–
VCC
V–
C2
100Ω
AD8541
VEE
C3
VCC
1kΩ
VEE
R4
99kΩ
04356-046
R3
04356-045
VIN
VCC
R1
Figure 46. Low Power Composite Amplifier
Figure 45. High Gain Composite Amplifier
Rev. B | Page 13 of 20
AD8603/AD8607/AD8609
BATTERY-POWERED APPLICATIONS
In addition to their low offset voltage and low input bias, the
AD8603/AD8607/AD8609 have a very low supply current of
40 μA, making the parts an excellent choice for portable electronics. The TSOT package allows the AD8603 to be used on
smaller board spaces.
PHOTODIODES
Figure 47 shows a simple photodiode circuit. The feedback
capacitor helps the circuit maintain stability. The signal
bandwidth can be increased at the expense of an increase in the
total noise; a low-pass filter can be implemented by a simple RC
network at the output to reduce the noise. The signal bandwidth
can be calculated by ½πR2C2 and the closed-loop bandwidth is
the intersection point of the open-loop gain and the noise gain.
The circuit shown in Figure 47 has a closed-loop bandwidth of
58 kHz and a signal bandwidth of 16 Hz. Increasing C2 to 50 pF
yields a closed-loop bandwidth of 65 kHz, but only 3.2 Hz of
signal bandwidth can be achieved.
Photodiodes have a wide range of applications from bar code
scanners to precision light meters and CAT scanners. The very
low noise and low input bias current of the AD8603/AD8607/
AD8609 make the parts very attractive amplifiers for I-V
conversion applications.
C2 10pF
R2 1000MΩ
VCC
C1
10pF
R1
1000MΩ
AD8603
VEE
Figure 47. Photodiode Circuit
Rev. B | Page 14 of 20
04356-047
The AD8603/AD8607/AD8609 are ideal for battery-powered
applications. The parts are tested at 5 V, 3.3 V, 2.7 V, and 1.8 V
and are suitable for various applications whether in single or
dual supply.
AD8603/AD8607/AD8609
OUTLINE DIMENSIONS
5.00 (0.1968)
4.80 (0.1890)
8
5
4.00 (0.1574)
3.80 (0.1497) 1
4
6.20 (0.2440)
5.80 (0.2284)
1.27 (0.0500)
BSC
0.50 (0.0196)
× 45°
0.25 (0.0099)
1.75 (0.0688)
1.35 (0.0532)
0.25 (0.0098)
0.10 (0.0040)
0.51 (0.0201)
COPLANARITY
SEATING 0.31 (0.0122)
0.10
PLANE
8°
0.25 (0.0098) 0° 1.27 (0.0500)
0.40 (0.0157)
0.17 (0.0067)
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 48. 8-Lead Standard Small Outline Package [SOIC_N]
(R-8)
Dimensions shown in millimeters and (inches)
2.90 BSC
5
4
2.80 BSC
1.60 BSC
1
2
3
PIN 1
0.95 BSC
1.90
BSC
*0.90
0.87
0.84
*1.00 MAX
0.10 MAX
0.50
0.30
0.20
0.08
8°
4°
0°
SEATING
PLANE
0.60
0.45
0.30
*COMPLIANT TO JEDEC STANDARDS MO-193-AB WITH
THE EXCEPTION OF PACKAGE HEIGHT AND THICKNESS.
Figure 49. 5-Lead Thin Small Outline Transistor Package [TSOT]
(UJ-5)
Dimensions shown in millimeters
3.00
BSC
8
3.00
BSC
1
5
4.90
BSC
4
PIN 1
0.65 BSC
1.10 MAX
0.15
0.00
0.38
0.22
COPLANARITY
0.10
0.23
0.08
8°
0°
SEATING
PLANE
COMPLIANT TO JEDEC STANDARDS MO-187-AA
Figure 50. 8-Lead Mini Small Outline Package [MSOP]
(RM-8)
Dimensions shown in millimeters
Rev. B | Page 15 of 20
0.80
0.60
0.40
AD8603/AD8607/AD8609
8.75 (0.3445)
8.55 (0.3366)
4.00 (0.1575)
3.80 (0.1496)
14
8
1
7
6.20 (0.2441)
5.80 (0.2283)
1.27 (0.0500)
BSC
0.25 (0.0098)
0.10 (0.0039)
0.51 (0.0201)
0.31 (0.0122)
COPLANARITY
0.10
0.50 (0.0197)
× 45°
0.25 (0.0098)
1.75 (0.0689)
1.35 (0.0531)
SEATING
PLANE
8°
0.25 (0.0098) 0° 1.27 (0.0500)
0.40 (0.0157)
0.17 (0.0067)
COMPLIANT TO JEDEC STANDARDS MS-012-AB
CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN
Figure 51. 14-Lead Standard Small Outline Package [SOIC_N]
(R-14)
Dimensions shown in millimeters and (inches)
5.10
5.00
4.90
14
8
4.50
4.40
4.30
6.40
BSC
1
7
PIN 1
1.05
1.00
0.80
0.65
BSC
1.20
MAX
0.15
0.05
0.30
0.19
0.20
0.09
SEATING
COPLANARITY
PLANE
0.10
8°
0°
COMPLIANT TO JEDEC STANDARDS MO-153-AB-1
Figure 52. 14-Lead Thin Shrink Small Outline Package [TSSOP]
(RU-14)
Dimensions shown in millimeters
Rev. B | Page 16 of 20
0.75
0.60
0.45
AD8603/AD8607/AD8609
ORDERING GUIDE
Model
AD8603AUJ-R2
AD8603AUJ-REEL
AD8603AUJ-REEL7
AD8603AUJZ-R2 1
AD8603AUJZ-REEL1
AD8603AUJZ-REEL71
AD8607ARM-R2
AD8607ARM-REEL
AD8607ARMZ-R21
AD8607ARMZ-REEL1
AD8607AR
AD8607AR-REEL
AD8607AR-REEL7
AD8607ARZ1
AD8607ARZ-REEL1
AD8607ARZ-REEL71
AD8609AR
AD8609AR-REEL
AD8609AR-REEL7
AD8609ARZ1
AD8609ARZ-REEL1
AD8609ARZ-REEL71
AD8609ARU
AR8609ARU-REEL
AD8609ARUZ1
AR8609ARUZ-REEL1
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
–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
5-Lead TSOT-23
5-Lead TSOT-23
5-Lead TSOT-23
5-Lead TSOT-23
5-Lead TSOT-23
5-Lead TSOT-23
8-Lead MSOP
8-Lead MSOP
8-Lead MSOP
8-Lead MSOP
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
14-Lead SOIC_N
14-Lead SOIC_N
14-Lead SOIC_N
14-Lead SOIC_N
14-Lead SOIC_N
14-Lead SOIC_N
14-Lead TSSOP
14-Lead TSSOP
14-Lead TSSOP
14-Lead TSSOP
Z = Pb-free part.
Rev. B | Page 17 of 20
Package Option
UJ-5
UJ-5
UJ-5
UJ-5
UJ-5
UJ-5
RM-8
RM-8
RM-8
RM-8
R-8
R-8
R-8
R-8
R-8
R-8
R-14
R-14
R-14
R-14
R-14
R-14
RU-14
RU-14
RU-14
RU-14
Branding
BFA
BFA
BFA
A0X
A0X
A0X
A00
A00
A0G
A0G
AD8603/AD8607/AD8609
NOTES
Rev. B | Page 18 of 20
AD8603/AD8607/AD8609
NOTES
Rev. B | Page 19 of 20
AD8603/AD8607/AD8609
NOTES
© 2005 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
C04356–0–6/05(B)
Rev. B | Page 20 of 20