AD AD8607ARM-REEL 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
OUT 1
V– 2
V+
4
–IN
OUT A 1
AD8607
TOP VIEW
(Not to Scale)
V– 4
8
V+
7
OUT B
6
–IN B
5
+IN B
OUT A 1
–IN A 2
AD8607
8
V+
7
OUT B
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
makes 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 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.
6 –IN B
TOP VIEW
V– 4 (Not to Scale) 5 +IN B
04356-003
Figure 2. 8-Lead MSOP (RM Suffix)
+IN A 3
GENERAL DESCRIPTION
04356-002
Figure 1. 5-Lead TSOT (UJ Suffix)
+IN A 3
Battery-powered instrumentation
Multipole filters
Sensors
Low power ASIC input or output amplifiers
5
TOP VIEW
(Not to Scale)
+IN 3
–IN A 2
APPLICATIONS
AD8603
04356-001
PIN CONFIGURATIONS
Figure 3. 8-Lead SOIC (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 maximum
Low input bias current: 1 pA maximum
Single-supply operation: 1.8 V to 5 V
Low noise: 22 nV/√Hz
Micropower: 50 μA maximum
Low distortion
No phase reversal
Unity gain stable
Figure 4. 14-Lead TSSOP (RU Suffix)
OUT A 1
14 OUT D
–IN A 2
+IN A 3
V+ 4
+IN B 5
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 (R Suffix)
Rev. C
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 ©2003–2008 Analog Devices, Inc. All rights reserved.
AD8603/AD8607/AD8609
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications..................................................................................... 12
Applications ....................................................................................... 1
No Phase Reversal ...................................................................... 12
General Description ......................................................................... 1
Input Overvoltage Protection ................................................... 12
Pin Configurations ........................................................................... 1
Driving Capacitive Loads .......................................................... 12
Revision History ............................................................................... 2
Proximity Sensors....................................................................... 13
Specifications..................................................................................... 3
Composite Amplifiers................................................................ 13
Electrical Characteristics ............................................................. 3
Battery-Powered Applications .................................................. 13
Absolute Maximum Ratings............................................................ 5
Photodiodes ................................................................................ 13
ESD Caution .................................................................................. 5
Outline Dimensions ....................................................................... 14
Typical Performance Characteristics ............................................. 6
Ordering Guide .......................................................................... 16
REVISION HISTORY
6/08—Rev. B to Rev. C
Changes to Table 1 ............................................................................ 3
Changes to Table 2 ............................................................................ 4
Changes to Figure 15 ........................................................................ 7
Changes to Figure 33 ...................................................................... 10
Changes to Figure 45 and Figure 47 ............................................. 13
Updated Outline Dimensions ....................................................... 14
Changes to Ordering Guide .......................................................... 16
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. C | Page 2 of 16
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
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
4.97
16
160
Short-Circuit Current
Closed-Loop Output Impedance
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current per Amplifier
PSRR
ISY
1.8 V < VS < 5 V
VO = 0 V
−40°C <TA < +125°C
DYNAMIC PERFORMANCE
Slew Rate
Settling Time 0.1%
Gain Bandwidth Product
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
Phase Margin
NOISE PERFORMANCE
Peak-to-Peak Noise
Voltage Noise Density
Current Noise Density
Channel Separation
ISC
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
ØO
en p-p
en
in
CS
±70
36
f = 10 kHz, AV = 1
Rev. C | Page 3 of 16
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
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
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
38
Short-Circuit Current
Closed-Loop Output Impedance
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current per Amplifier
PSRR
ISY
1.8 V < VS < 5 V
VO = 0 V
−40°C < TA < +85°C
DYNAMIC PERFORMANCE
Slew Rate
Settling Time 0.1%
Gain Bandwidth Product
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
f = 10 kHz
f = 100 kHz
2.3
25
22
0.05
−115
−110
Phase Margin
NOISE PERFORMANCE
Peak-to-Peak Noise
Voltage Noise Density
Current Noise Density
Channel Separation
ISC
ZOUT
IL = 1 mA
−40°C to +125°C
IL = 1 mA
−40°C to +125°C
98
ØO
en p-p
en
in
CS
±10
36
f = 10 kHz, AV = 1
Rev. C | Page 4 of 16
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
Absolute maximum ratings apply at 25°C, unless otherwise noted.
Table 3.
Parameter
Supply Voltage
Input Voltage
Differential Input Voltage
Output Short-Circuit Duration to GND
Storage Temperature Range
Lead Temperature (Soldering, 60 sec)
Operating Temperature Range
Junction Temperature Range
Rating
6V
GND to VS
±6 V
Indefinite
−65°C to +150°C
300°C
−40°C to +125°C
−65°C to +150°C
Table 4. Package Characteristics
Package Type
5-Lead TSOT (UJ)
8-Lead MSOP (RM)
8-Lead SOIC_N (R)
14-Lead SOIC_N (R)
14-Lead TSSOP (RU)
θJA1
207
210
158
120
180
θJC
61
45
43
36
35
Unit
°C/W
°C/W
°C/W
°C/W
°C/W
1
θJA is specified for the worst-case conditions, that is, θJA is specified for a
device soldered in a circuit board for surface-mount packages.
ESD CAUTION
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. C | Page 5 of 16
AD8603/AD8607/AD8609
TYPICAL PERFORMANCE CHARACTERISTICS
300
2600
2200
VS = 5V
TA = 25°C
VCM = 0V TO 5V
200
150
1800
100
1600
50
VOS (µV)
1400
1200
1000
–150
600
400
–200
200
–250
–270 –210 –150
–90 –30 0 30
VOS (µV)
90
150
210
270
–300
0.3
VS = ±2.5V
TA = –40°C TO +125°C
VCM = 0V
1.2
1.5 1.8
VCM (V)
(V)
2.1
2.4
2.7
3.0
3.3
VS = ±2.5V
20
15
10
5
300
250
200
150
100
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
04356-007
0
25
0
75
50
TEMPERATURE (°C)
100
125
04356-010
50
Figure 10. Input Bias Current vs. Temperature
Figure 7. Input Offset Voltage Drift Distribution
1000
OUTPUT VOLTAGE TO SUPPLY RAIL (mV)
VS = 5V
TA = 25°C
200
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
100
10
SOURCE
1
Figure 8. Input Offset Voltage vs. Common-Mode Voltage
SINK
0.1
0.01
0.001
04356-008
0
VS = 5V
TA = 25°C
0.01
0.1
LOAD CURRENT (mA)
1
Figure 11. Output Voltage to Supply Rail vs. Load Current
Rev. C | Page 6 of 16
10
04356-011
300
250
VOS (µV)
0.9
350
INPUT BIAS CURRENT (pA)
25
–300
0.6
400
30
0
0
Figure 9. Input Offset Voltage vs. Common-Mode Voltage
Figure 6. Input Offset Voltage Distribution
NUMBERS OF AMPLIFIERS
0
–50
–100
800
04356-006
NUMBER OF AMPLIFIERS
2000
0
VS = 3.3V
TA = 25°C
250
04356-009
2400
AD8603/AD8607/AD8609
350
1575
OUTPUT IMPEDANCE (Ω)
200
VOL @ 10mA LOAD
150
100
VDD – VOH @ 1mA LOAD
20
35
50
65
TEMPERATURE (°C)
80
95
110
525
350
125
0
100
140
180
120
135
100
90
20
45
0
0
–45
–90
–60
–135
–20
–80
–180
–40
20
0
–225
10M
–60
100
VS = 5V
VIN = 4.9V p-p
TA = 25°C
AV = 1
100
60
2.5
2.0
40
20
0
1.0
–20
0.5
–40
1
FREQUENCY (kHz)
10
100
04356-014
1.5
–60
10
100
1k
FREQUENCY (Hz)
10k
Figure 17. PSRR vs. Frequency
Figure 14. Closed-Loop Output Voltage Swing vs. Frequency
Rev. C | Page 7 of 16
100k
04356-017
PSRR (dB)
80
3.0
0.1
VS = ±2.5V
120
3.5
0
0.01
100k
140
5.0
4.0
1k
10k
FREQUENCY (Hz)
Figure 16. CMRR vs. Frequency
Figure 13. Open-Loop Gain and Phase vs. Frequency
4.5
VS = ±2.5V
40
–40
1M
100k
60
–20
100k
FREQUENCY (Hz)
10k
FREQUENCY (Hz)
80
CMRR (dB)
40
04356-013
OPEN-LOOP GAIN (dB)
60
225
PHASE (Degree)
VS = ±2.5V
RL = 100kΩ
CL = 20pF
Φ = 70.9°
80
1k
Figure 15. Output Impedance vs. Frequency
100
10k
AV = 1
700
Figure 12. Output Voltage Swing vs. Temperature
–100
1k
AV = 10
875
04356-015
5
AV = 100
1050
175
VOL @ 1mA LOAD
–10
1225
04356-016
50
0
–40 –25
OUTPUT VOLTAGE SWING (V p-p)
VS = ±2.5V, ±0.9V
1400
VDD – VOH @ 10mA LOAD
250
04356-012
OUTPUT VOLTAGE SWING (mV)
300
1750
VS = 5V
TA = 25°C
AD8603/AD8607/AD8609
60
VS = 5V, 1.8V
VS = 5V
OS–
30
20
OS+
10
0
10
100
LOAD CAPACITANCE (pF)
1000
TIME (1s/DIV)
Figure 18. Small Signal Overshoot vs. Load Capacitance
04356-021
VOLTAGE NOISE (1µV/DIV)
40
04356-018
SMALL SIGNAL OVERSHOOT (%)
50
Figure 21. 0.1 Hz to 10 Hz Input Voltage Noise
60
VS = 5V
RL = 10kΩ
CL = 200pF
AV = 1
VS = ±2.5V
55
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
100
Figure 22. Small Signal Transient
TA = 25°C
90
VS = 5V
RL = 10kΩ
CL = 200pF
AV = 1
80
VOLTAGE (1V/DIV)
70
60
50
40
30
20
0
0
1
2
3
SUPPLY VOLTAGE (V)
4
5
TIME (20µs/DIV)
Figure 23. Large Signal Transient
Figure 20. Supply Current vs. Supply Voltage
Rev. C | Page 8 of 16
04356-023
10
04356-020
SUPPLY CURRENT (µA)
04356-022
–25
04356-019
5
0
–40
AD8603/AD8607/AD8609
0V
VIN (mV)
0V
04356-024
–50mV
TIME (4μs/DIV))
(40µs/DIV)
154
132
110
88
66
44
22
0
0
+2.5V
0V
0V
–50mV
4
5
6
FREQUENCY (kHz)
7
8
9
10
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
Figure 25. Positive Overload Recovery
–60
60
0
VOS (µV)
120
180
240
300
04356-028
100
TIME (4µs/DIV)
Figure 28. VOS Distribution
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
Figure 29. Input Offset Voltage vs. Common-Mode Voltage
Figure 26. Voltage Noise Density vs. Frequency
Rev. C | Page 9 of 16
1.8
04356-029
–250
0
04356-026
VOLTAGE NOISE DENSITY (nV/√Hz)
3
800
750
VS = ±2.5V
RL = 10kΩ
AV = 100
VIN = 50mV
VIN (mV)
2
Figure 27. Voltage Noise Density vs. Frequency
NUMBER OF AMPLIFIERS
VOUT (V)
Figure 24. Negative Overload Recovery
1
04356-027
+2.5V
VS = ±2.5V
VOLTAGE NOISE DENSITY (nV/√Hz)
VOUT (V)
176
VS = ±2.5V
RL = 10kΩ
AV = 100
VIN = 50mV
AD8603/AD8607/AD8609
225
80
60
OPEN-LOOP GAIN (dB)
100
10
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
1k
100k
FREQUENCY (Hz)
1M
–225
10M
140
120
90
VS = 1.8V
80
VS = 1.8V
100
80
VDD – VOH @ 1mA LOAD
60
CMRR (dB)
60
50
VOL @ 1mA LOAD
40
40
20
30
0
20
–20
10
–40
0
–40 –25
–10
5
35
50
65
20
TEMPERATURE (°C)
80
95
110
125
–60
100
Figure 31. Output Voltage Swing vs. Temperature
1k
10k
FREQUENCY (Hz)
100k
04356-034
70
04356-031
Figure 34. CMRR vs. Frequency
60
1.8
OUTPUT VOLTAGE SWING (V p-p)
VS = 1.8V
TA = 25°C
AV = 1
40
30
20
OS–
10
1.5
1.2
VS = 1.8V
VIN = 1.7V p-p
TA = 25°C
AV = 1
0.9
0.6
0.3
0
10
100
LOAD CAPACITANCE (pF)
1000
04356-032
OS+
Figure 32. Small Signal Overshoot vs. Load Capacitance
0
0.01
0.1
1
FREQUENCY (kHz)
10
100
Figure 35. Closed-Loop Output Voltage Swing vs. Frequency
Rev. C | Page 10 of 16
04356-035
OUTPUT VOLTAGE SWING (mV)
10k
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 (Degrees)
VS = ±0.9V
RL = 100kΩ
CL = 20pF
Φ = 70°
04356-033
100
VS = 1.8V
TA = 25°C
04356-030
OUTPUT VOLTAGE TO SUPPLY RAIL (mV)
1000
AD8603/AD8607/AD8609
176
VS = 1.8V
RL = 10kΩ
CL = 200pF
AV = 1
VS = ±0.9V
TIME (4µs/DIV)
132
110
88
66
44
22
0
0
1
2
3
4
5
6
FREQUENCY (kHz)
7
8
9
10
04356-039
04356-036
VOLTAGE (50mV/DIV)
VOLTAGE NOISE DENSITY (nV/√Hz)
154
Figure 39. Voltage Noise Density vs. Frequency
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
TIME (20µs/DIV)
Figure 37. Large Signal Transient
140
112
84
56
28
0.1
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
1k
10k
FREQUENCY (Hz)
100k
Figure 40. Channel Separation vs. Frequency
168
0
–140
100
Figure 38. Voltage Noise Density vs. Frequency
Rev. C | Page 11 of 16
1M
04356-040
04356-037
–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
Figure 42. Output Response to a 2 nF Capacitive Load, Without Snubber
V–
V+
Figure 41. No Phase Response
200mV
INPUT OVERVOLTAGE PROTECTION
+
–
VCC
RS
150Ω
CS
47pF
CL
04356-043
TIME (4µs/DIV)
04356-041
VEE
Figure 43. Snubber Network
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.
VSY = ±0.9V
VIN = 100mV
CL = 2nF
RL = 10kΩ
RS = 150Ω
CS = 470pF
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 following equation:
(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.
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.
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
Optimum values for RS and CS are determined empirically;
Table 5 lists a few starting values.
Table 5. Optimum Values for the Snubber Network
CL (pF)
100 to ~500
1500
1600 to ~2000
Rev. C | Page 12 of 16
RS (Ω)
500
100
400
CS (pF)
680
330
100
AD8603/AD8607/AD8609
PROXIMITY SENSORS
BATTERY-POWERED APPLICATIONS
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.
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.
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 (see Figure 45) improves the phase margin.
Picking CF = 50 pF yields a phase margin of about 45° for the
values shown in Figure 45.
CF
R2
99kΩ
VEE
AD8603
V–
VCC
U5
V–
R3
1kΩ
VEE
R4
04356-045
VCC
VIN
99kΩ
Photodiodes have a wide range of applications from barcode
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.
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.
AD8541
V+
V+
PHOTODIODES
C2
10pF
Figure 45. High Gain Composite Amplifier
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 because they are divided
by the high gain of the AD8603.
The circuit in Figure 46 offers high bandwidth (nearly double
that of the AD8603), high output current, and very low power
consumption of less than 100 μA.
R2
VEE
R1
1kΩ
VCC
AD8603
R3
1kΩ
V+
V–
C2
V+
VCC
R4
100Ω
AD8541
VEE
C3
04356-046
VIN
VEE
V–
AD8603
R1
1000MΩ
C1
10pF
V+
VCC
Figure 47. Photodiode Circuit
100kΩ
V–
R2
1000MΩ
Figure 46. Low Power Composite Amplifier
Rev. C | Page 13 of 16
04356-047
R1
1kΩ
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.
AD8603/AD8607/AD8609
OUTLINE DIMENSIONS
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 48. 5-Lead Thin Small Outline Transistor Package [TSOT]
(UJ-5)
Dimensions shown in millimeters
3.20
3.00
2.80
8
3.20
3.00
2.80
1
5
5.15
4.90
4.65
4
PIN 1
0.65 BSC
0.95
0.85
0.75
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 49. 8-Lead Mini Small Outline Package [MSOP]
(RM-8)
Dimensions shown in millimeters
Rev. C | Page 14 of 16
0.80
0.60
0.40
AD8603/AD8607/AD8609
5.00 (0.1968)
4.80 (0.1890)
8
4.00 (0.1574)
3.80 (0.1497)
5
1
4
1.27 (0.0500)
BSC
0.25 (0.0098)
0.10 (0.0040)
6.20 (0.2441)
5.80 (0.2284)
1.75 (0.0688)
1.35 (0.0532)
0.51 (0.0201)
0.31 (0.0122)
COPLANARITY
0.10
SEATING
PLANE
0.50 (0.0196)
0.25 (0.0099)
45°
8°
0°
0.25 (0.0098)
0.17 (0.0067)
1.27 (0.0500)
0.40 (0.0157)
012407-A
COMPLIANT TO JEDEC STANDARDS MS-012-A A
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 50. 8-Lead Standard Small Outline Package [SOIC_N]
(R-8)
Dimensions shown in millimeters and (inches)
8.75 (0.3445)
8.55 (0.3366)
4.00 (0.1575)
3.80 (0.1496)
8
14
1
7
1.27 (0.0500)
BSC
0.50 (0.0197)
0.25 (0.0098)
1.75 (0.0689)
1.35 (0.0531)
0.25 (0.0098)
0.10 (0.0039)
COPLANARITY
0.10
6.20 (0.2441)
5.80 (0.2283)
SEATING
PLANE
0.51 (0.0201)
0.31 (0.0122)
8°
0°
0.25 (0.0098)
0.17 (0.0067)
1.27 (0.0500)
0.40 (0.0157)
060606-A
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
45°
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. C | Page 15 of 16
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
AD8609ARU-REEL
AD8609ARUZ1
AD8609ARUZ-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
5-Lead TSOT
5-Lead TSOT
5-Lead TSOT
5-Lead TSOT
5-Lead TSOT
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 = RoHS Compliant Part.
©2003–2008 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D04356-0-6/08(C)
Rev. C | Page 16 of 16
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