AD AD8544 General-purpose cmos rail-to-rail amplifier Datasheet

General-Purpose CMOS
Rail-to-Rail Amplifiers
AD8541/AD8542/AD8544
APPLICATIONS
ASIC input or output amplifiers
Sensor interfaces
Piezoelectric transducer amplifiers
Medical instrumentations
Mobile communications
Audio outputs
Portable systems
PIN CONFIGURATIONS
OUT A 1
AD8541
5 V+
V– 2
+IN A 3
4 –IN A
00935-001
Single-supply operation: 2.7 V to 5.5 V
Low supply current: 45 μA/amplifier
Wide bandwidth: 1 MHz
No phase reversal
Low input currents: 4 pA
Unity gain stable
Rail-to-rail input and output
Figure 1. 5-Lead SC70 and 5-Lead SOT-23
(KS and RJ Suffixes)
8
NC
2
7
V+
+IN A 3
6
OUT A
4
5
NC
NC 1
–IN A
V–
AD8541
00935-002
FEATURES
NC = NO CONNECT
Figure 2. 8-Lead SOIC
(R Suffix)
Very low input bias currents enable the AD8541/AD8542/AD8544
to be used for integrators, photodiode amplifiers, piezoelectric
sensors, and other applications with high source impedance.
The supply current is only 45 μA per amplifier, ideal for battery
operation.
Rail-to-rail inputs and outputs are useful to designers buffering
ASICs in single-supply systems. The AD8541/AD8542/AD8544
are optimized to maintain high gains at lower supply voltages,
making them useful for active filters and gain stages.
The AD8541/AD8542/AD8544 are specified over the extended
industrial temperature range (–40°C to +125°C). The AD8541
is available in 8-lead SOIC, 5-lead SC70, and 5-lead SOT-23
packages. The AD8542 is available in 8-lead SOIC, 8-lead
MSOP, and 8-lead TSSOP surface-mount packages. The
AD8544 is available in 14-lead narrow SOIC and 14-lead
TSSOP surface-mount packages. All MSOP, SC70, and SOT
versions are available in tape and reel only.
OUT A
1
–IN A
AD8542
8
V+
2
7
OUT B
+IN A
3
6
–IN B
V–
4
5
+IN B
Figure 3. 8-Lead SOIC, 8-Lead MSOP, and 8-Lead TSSOP
(R, RM, and RU Suffixes)
OUT A
1
14 OUT D
–IN A
2
13 –IN D
+IN A
3
12 +IN D
V+
4
+IN B
5
–IN B
6
9
–IN C
OUT B
7
8
OUT C
AD8544
11 V–
10 +IN C
00935-004
The AD8541/AD8542/AD8544 are single, dual, and quad railto-rail input and output single-supply amplifiers featuring very
low supply current and 1 MHz bandwidth. All are guaranteed to
operate from a 2.7 V single supply as well as a 5 V supply. These
parts provide 1 MHz bandwidth at a low current consumption
of 45 μA per amplifier.
00935-003
GENERAL DESCRIPTION
Figure 4. 14-Lead SOIC and 14-Lead TSSOP
(R and RU Suffixes)
Rev. E
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
©2007 Analog Devices, Inc. All rights reserved.
AD8541/AD8542/AD8544
TABLE OF CONTENTS
Features .............................................................................................. 1
Typical Performance Characteristics ..............................................7
Applications....................................................................................... 1
Theory of Operation ...................................................................... 12
General Description ......................................................................... 1
Notes on the AD854x Amplifiers............................................. 12
Pin Configurations ........................................................................... 1
Applications..................................................................................... 13
Revision History ............................................................................... 2
Notch Filter ................................................................................. 13
Specifications..................................................................................... 3
Comparator Function ................................................................ 13
Electrical Characteristics............................................................. 3
Photodiode Application ............................................................ 14
Absolute Maximum Ratings............................................................ 6
Outline Dimensions ....................................................................... 15
Thermal Resistance ...................................................................... 6
Ordering Guide .......................................................................... 17
ESD Caution.................................................................................. 6
REVISION HISTORY
1/07—Rev. D to Rev. E
Updated Format..................................................................Universal
Changes to Photodiode Application Section .............................. 14
Changes to Ordering Guide .......................................................... 17
8/04—Rev. C to Rev. D
Changes to Ordering Guide ............................................................ 5
Changes to Figure 3........................................................................ 10
Updated Outline Dimensions ....................................................... 12
1/03—Rev. B to Rev. C
Updated Format..................................................................Universal
Changes to General Description .................................................... 1
Changes to Ordering Guide ............................................................ 5
Changes to Outline Dimensions................................................... 12
Rev. E | Page 2 of 20
AD8541/AD8542/AD8544
SPECIFICATIONS
ELECTRICAL CHARACTERISTICS
VS = 2.7 V, VCM = 1.35 V, TA = 25°C, unless otherwise noted.
Table 1.
Parameter
INPUT CHARACTERISTICS
Offset Voltage
Symbol
Conditions
Min
VOS
Typ
Max
Unit
1
6
7
60
100
1000
30
50
500
2.7
mV
mV
pA
pA
pA
pA
pA
pA
V
dB
dB
V/mV
V/mV
V/mV
μV/°C
fA/°C
fA/°C
fA/°C
–40°C ≤ TA ≤ +125°C
Input Bias Current
IB
4
–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
CMRR
Large Signal Voltage Gain
AVO
Offset Voltage Drift
Bias Current Drift
ΔVOS/ΔT
ΔIB/ΔT
Offset Current Drift
ΔIOS/ΔT
VCM = 0 V to 2.7 V
–40°C ≤ TA ≤ +125°C
RL = 100 kΩ , VO = 0.5 V to 2.2 V
–40°C ≤ TA ≤ +85°C
–40°C ≤ TA ≤ +125°C
–40°C ≤ TA ≤ +125°C
–40°C ≤ TA ≤ +85°C
–40°C ≤ TA ≤ +125°C
–40°C ≤ TA ≤ +125°C
0
40
38
100
50
2
45
500
4
100
2000
25
OUTPUT CHARACTERISTICS
Output Voltage High
VOH
Output Voltage Low
VOL
Output Current
IOUT
±ISC
ZOUT
Closed-Loop Output Impedance
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current/Amplifier
DYNAMIC PERFORMANCE
Slew Rate
Settling Time
Gain Bandwidth Product
Phase Margin
PSRR
IL = 1 mA
–40°C ≤ TA ≤ +125°C
IL = 1 mA
–40°C ≤ TA ≤ +125°C
VOUT = VS – 1 V
2.575
2.550
35
100
125
15
±20
50
f = 200 kHz, AV = 1
VS = 2.5 V to 6 V
–40°C ≤ TA ≤ +125°C
VO = 0 V
–40°C ≤ TA ≤ +125°C
65
60
SR
tS
GBP
Φo
RL = 100 kΩ
To 0.1% (1 V step)
0.4
en
en
in
f = 1 kHz
f = 10 kHz
ISY
2.65
76
38
55
75
V
V
mV
mV
mA
mA
Ω
dB
dB
μA
μA
0.75
5
980
63
V/μs
μs
kHz
Degrees
40
38
<0.1
nV/√Hz
nV/√Hz
pA/√Hz
NOISE PERFORMANCE
Voltage Noise Density
Current Noise Density
Rev. E | Page 3 of 20
AD8541/AD8542/AD8544
VS = 3.0 V, VCM = 1.5 V, TA = 25°C, unless otherwise noted.
Table 2.
Parameter
INPUT CHARACTERISTICS
Offset Voltage
Symbol
Conditions
Min
VOS
Typ
Max
Unit
1
6
7
60
100
1000
30
50
500
3
mV
mV
pA
pA
pA
pA
pA
pA
V
dB
dB
V/mV
V/mV
V/mV
μV/°C
fA/°C
fA/°C
fA/°C
–40°C ≤ TA ≤ +125°C
Input Bias Current
IB
4
–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
CMRR
Large Signal Voltage Gain
AVO
Offset Voltage Drift
Bias Current Drift
ΔVOS/ΔT
ΔIB/ΔT
Offset Current Drift
OUTPUT CHARACTERISTICS
Output Voltage High
ΔIOS/ΔT
VOH
Output Voltage Low
VOL
Output Current
IOUT
±ISC
ZOUT
Closed-Loop Output Impedance
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current/Amplifier
DYNAMIC PERFORMANCE
Slew Rate
Settling Time
Gain Bandwidth Product
Phase Margin
NOISE PERFORMANCE
Voltage Noise Density
Current Noise Density
PSRR
VCM = 0 V to 3 V
–40°C ≤ TA ≤ +125°C
RL = 100 kΩ , VO = 0.5 V to 2.2 V
–40°C ≤ TA ≤ +85°C
–40°C ≤ TA ≤ +125°C
–40°C ≤ TA ≤ +125°C
–40°C ≤ TA ≤ +85°C
–40°C ≤ TA ≤ +125°C
–40°C ≤ TA ≤ +125°C
IL = 1 mA
–40°C ≤ TA ≤ +125°C
IL = 1 mA
–40°C ≤ TA ≤ +125°C
VOUT = VS – 1 V
0
40
38
100
50
2
2.875
2.850
2.955
32
100
125
18
±25
50
f = 200 kHz, AV = 1
65
60
SR
tS
GBP
Φo
RL = 100 kΩ
To 0.01% (1 V step)
0.4
en
en
in
f = 1 kHz
f = 10 kHz
Rev. E | Page 4 of 20
500
4
100
2000
25
VS = 2.5 V to 6 V
–40°C ≤ TA ≤ +125°C
VO = 0 V
–40°C ≤ TA ≤ +125°C
ISY
45
76
40
60
75
V
V
mV
mV
mA
mA
Ω
dB
dB
μA
μA
0.8
5
980
64
V/μs
μs
kHz
Degrees
42
38
<0.1
nV/√Hz
nV/√Hz
pA/√Hz
AD8541/AD8542/AD8544
VS = 5.0 V, VCM = 2.5 V, TA = 25°C, unless otherwise noted.
Table 3.
Parameter
INPUT CHARACTERISTICS
Offset Voltage
Symbol
Conditions
Min
VOS
Typ
Max
Unit
1
6
7
60
100
1000
30
50
500
5
mV
mV
pA
pA
pA
pA
pA
pA
V
dB
dB
V/mV
V/mV
V/mV
μV/°C
fA/°C
fA/°C
fA/°C
–40°C ≤ TA ≤ +125°C
Input Bias Current
IB
4
–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
CMRR
Large Signal Voltage Gain
AVO
Offset Voltage Drift
Bias Current Drift
ΔVOS/ΔT
ΔIB/ΔT
Offset Current Drift
ΔIOS/ΔT
VCM = 0 V to 5 V
–40°C ≤ TA ≤ +125°C
RL = 100 kΩ , VO = 0.5 V to 2.2 V
–40°C ≤ TA ≤ +85°C
–40°C ≤ TA ≤ +125°C
–40°C ≤ TA ≤ +125°C
–40°C ≤ TA ≤ +85°C
–40°C ≤ TA ≤ +125°C
–40°C ≤ TA ≤ +125°C
0
40
38
20
10
2
48
40
4
100
2000
25
OUTPUT CHARACTERISTICS
Output Voltage High
VOH
Output Voltage Low
VOL
Output Current
IOUT
±ISC
ZOUT
Closed-Loop Output Impedance
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current/Amplifier
DYNAMIC PERFORMANCE
Slew Rate
Full-Power Bandwidth
Settling Time
Gain Bandwidth Product
Phase Margin
NOISE PERFORMANCE
Voltage Noise Density
Current Noise Density
PSRR
IL = 1 mA
–40°C ≤ TA ≤ +125°C
IL = 1 mA
–40°C ≤ TA ≤ +125°C
VOUT = VS – 1 V
4.9
4.875
25
f = 200 kHz, AV = 1
65
60
SR
BWP
tS
GBP
Φo
RL = 100 kΩ, CL = 200 pF
1% distortion
To 0.1% (1 V step)
0.45
en
en
in
f = 1 kHz
f = 10 kHz
Rev. E | Page 5 of 20
100
125
30
±60
45
VS = 2.5 V to 6 V
–40°C ≤ TA ≤ +125°C
VO = 0 V
–40°C ≤ TA ≤ +125°C
ISY
4.965
76
45
65
85
V
V
mV
mV
mA
mA
Ω
dB
dB
μA
μA
0.92
70
6
1000
67
V/μs
kHz
μs
kHz
Degrees
42
38
<0.1
nV/√Hz
nV/√Hz
pA/√Hz
AD8541/AD8542/AD8544
ABSOLUTE MAXIMUM RATINGS
THERMAL RESISTANCE
Table 4.
Parameter
Supply Voltage (VS)
Input Voltage
Differential Input Voltage1
Storage Temperature Range
Operating Temperature Range
Junction Temperature Range
Lead Temperature (Soldering, 60 sec)
1
Rating
6V
GND to VS
±6 V
−65°C to +150°C
−40°C to +125°C
−65°C to +150°C
300°C
For supplies less than 6 V, the differential input voltage is equal to ±VS.
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.
θJA is specified for the worst-case conditions, that is, a device
soldered in a circuit board for surface-mount packages.
Table 5.
Package Type
5-Lead SC70 (KS)
5-Lead SOT-23 (RJ)
8-Lead SOIC (R)
8-Lead MSOP (RM)
8-Lead TSSOP (RU)
14-Lead SOIC (R)
14-Lead TSSOP (RU)
ESD CAUTION
Rev. E | Page 6 of 20
θJA
376
230
158
210
240
120
240
θJC
126
146
43
45
43
36
43
Unit
°C/W
°C/W
°C/W
°C/W
°C/W
°C/W
°C/W
AD8541/AD8542/AD8544
TYPICAL PERFORMANCE CHARACTERISTICS
180
160
VS = 2.7V AND 5V
VCM = VS/2
350
140
300
INPUT BIAS CURRENT (pA)
120
100
80
60
40
250
200
150
100
–3.5
–2.5 –1.5
–0.5
0.5
1.5
2.5
INPUT OFFSET VOLTAGE (mV)
3.5
0
–40
00935-005
0
–4.5
4.5
Figure 5. Input Offset Voltage Distribution
100
120
140
VS = 2.7V AND 5V
VCM = VS/2
6
0
INPUT OFFSET CURRENT (pA)
–0.5
–1.0
–1.5
–2.0
–2.5
–3.0
5
4
3
2
1
0
–3.5
–35
5
–15
25
45
65
85
TEMPERATURE (°C)
105
145
125
–1
–55
00935-006
–4.0
–55
Figure 6. Input Offset Voltage vs. Temperature
–35
–15
5
25
45
65
85
TEMPERATURE (°C)
105
125
145
00935-009
INPUT OFFSET VOLTAGE (mV)
20
40
60
80
TEMPERATURE (°C)
7
VS = 2.7V AND 5V
VCM = VS/2
0.5
Figure 9. Input Offset Current vs. Temperature
9
160
VS = 2.7V AND 5V
VCM = VS/2
VS = 2.7V
TA = 25°C
POWER SUPPLY REJECTION (dB)
140
7
6
5
4
3
2
1
120
100
80
–PSRR
60
+PSRR
40
20
0
–20
0
–0.5
0.5
1.5
2.5
3.5
COMMON-MODE VOLTAGE (V)
4.5
5.5
–40
100
00935-007
INPUT BIAS CURRENT (pA)
0
Figure 8. Input Bias Current vs. Temperature
1.0
8
–20
00935-008
50
20
Figure 7. Input Bias Current vs. Common-Mode Voltage
1k
10k
100k
FREQUENCY (Hz)
1M
Figure 10. Power Supply Rejection Ratio vs. Frequency
Rev. E | Page 7 of 20
10M
00935-010
NUMBER OF AMPLIFIERS
400
VS = 5V
VCM = 2.5V
TA = 25°C
AD8541/AD8542/AD8544
60
SMALL SIGNAL OVERSHOOT (%)
100
SOURCE
10
SINK
1
0.1
0.01
0.1
1
LOAD CURRENT (mA)
10
100
+OS
40
–OS
30
20
10
0
00935-011
0.01
0.001
50
10
Figure 11. Output Voltage to Supply Rail vs. Load Current
3.0
SMALL SIGNAL OVERSHOOT (%)
1.5
1.0
0.5
10k
100k
FREQUENCY (Hz)
1M
10M
50
40
+OS
30
–OS
20
10
0
00935-012
1k
VS = 2.7V
RL = 2kΩ
TA = 25°C
10
VS = 2.7V
RL = 100kΩ
CL = 300pF
AV = 1
TA = 25°C
VS = 2.7V
RL = ∞
TA = 25°C
+OS
1.35V
30
–OS
20
10
50mV
0
10
100
1k
CAPACITANCE (pF)
10k
10µs
00935-013
SMALL SIGNAL OVERSHOOT (%)
60
40
10k
Figure 15. Small Signal Overshoot vs. Load Capacitance
Figure 12. Closed-Loop Output Voltage Swing vs. Frequency
50
100
1k
CAPACITANCE (pF)
Figure 16. Small Signal Transient Response
Figure 13. Small Signal Overshoot vs. Load Capacitance
Rev. E | Page 8 of 20
00935-016
OUTPUT SWING (V p-p)
60
2.0
0
10k
Figure 14. Small Signal Overshoot vs. Load Capacitance
VS = 2.7V
VIN = 2.5V p-p
RL = 2kΩ
TA = 25°C
2.5
100
1k
CAPACITANCE (pF)
00935-015
1k
Δ OUTPUT VOLTAGE (mV)
VS = 2.7V
RL = 10kΩ
TA = 25°C
VS = 2.7V
TA = 25°C
00935-014
10k
AD8541/AD8542/AD8544
90
VS = 2.7V
RL = 2kΩ
AV = 1
TA = 25°C
COMMON-MODE REJECTION (dB)
10µs
70
60
50
40
30
20
10
0
–10
1k
10k
100k
FREQUENCY (Hz)
1M
10M
00935-020
500mV
00935-017
1.35V
Figure 20. Common-Mode Rejection Ratio vs. Frequency
Figure 17. Large Signal Transient Response
10k
VS = 2.7V
RL = NO LOAD
TA = 25°C
VS = 5V
TA = 25°C
60
90
40
135
20
180
0
Δ OUTPUT VOLTAGE (mV)
45
PHASE SHIFT (Degrees)
1k
80
100
SOURCE
10
SINK
1
10k
100k
FREQUENCY (Hz)
1M
10M
0.01
0.001
0.01
0.1
1
LOAD CURRENT (mA)
10
100
00935-021
1k
00935-018
0.1
Figure 21. Output Voltage to Supply Rail vs. Frequency
Figure 18. Open-Loop Gain and Phase vs. Frequency
5.0
VS = 5V
TA = 25°C
140
VS = 5V
VIN = 4.9V p-p
RL = NO LOAD
TA = 25°C
4.5
4.0
OUTPUT SWING (V p-p)
120
100
80
–PSRR
60
+PSRR
40
20
3.5
3.0
2.5
2.0
1.5
0
1.0
–20
0.5
1k
10k
100k
FREQUENCY (Hz)
1M
10M
0
00935-019
–40
100
Figure 19. Power Supply Rejection Ratio vs. Frequency
1k
10k
100k
FREQUENCY (Hz)
1M
10M
Figure 22. Closed-Loop Output Voltage Swing vs. Frequency
Rev. E | Page 9 of 20
00935-022
160
POWER SUPPLY REJECTION RATIO (dB)
GAIN (dB)
VS = 5V
TA = 25°C
80
AD8541/AD8542/AD8544
5.0
4.0
SMALL SIGNAL OVERSHOOT (%)
4.5
OUTPUT SWING (V p-p)
60
VS = 5V
VIN = 4.9V p-p
RL = 2kΩ
TA = 25°C
3.5
3.0
2.5
2.0
1.5
1.0
VS = 5V
RL = ∞
TA = 25°C
50
40
+OS
30
–OS
20
10
1k
10k
100k
FREQUENCY (Hz)
1M
10M
0
10
00935-023
0
Figure 23. Closed-Loop Output Voltage Swing vs. Frequency
+OS
2.5V
30
–OS
10
10
100
1k
CAPACITANCE (pF)
10k
Figure 27. Small Signal Transient Response
Figure 24. Small Signal Overshoot vs. Load Capacitance
60
VS = 5V
RL = 2kΩ
AV = 1
TA = 25°C
VS = 5V
RL = 2kΩ
TA = 25°C
50
10µs
00935-024
50mV
00935-027
20
40
+OS
2.5V
30
–OS
20
10
10
100
1k
CAPACITANCE (pF)
10k
10µs
00935-025
1V
0
Figure 25. Small Signal Overshoot vs. Load Capacitance
Figure 28. Large Signal Transient Response
Rev. E | Page 10 of 20
00935-028
SMALL SIGNAL OVERSHOOT (%)
VS = 5V
RL = 100kΩ
CL = 300pF
AV = 1
TA = 25°C
VS = 5V
RL = 10kΩ
TA = 25°C
40
0
SMALL SIGNAL OVERSHOOT (%)
10k
Figure 26. Small Signal Overshoot vs. Load Capacitance
60
50
100
1k
CAPACITANCE (pF)
00935-026
0.5
AD8541/AD8542/AD8544
55
90
40
135
20
180
1k
10k
100k
FREQUENCY (Hz)
1M
00935-029
0
10M
50
VS = 5V
45
40
VS = 2.7V
35
30
25
20
–55
–15
5
25
45
65
85
TEMPERATURE (°C)
105
125
145
Figure 32. Supply Current per Amplifier vs. Temperature
Figure 29. Open-Loop Gain and Phase vs. Frequency
1000
VS = 5V
RL = 10kΩ
AV = 1
TA = 25°C
VIN
–35
00935-032
60
SUPPLY CURRENT/AMPLIFIER (µA)
45
PHASE SHIFT (Degrees)
80
900
800
VOUT
VS = 2.7V AND 5V
AV = 1
TA = 25°C
IMPEDANCE (Ω)
700
2.5V
600
500
400
300
20µs
100
0
1k
10k
100k
1M
FREQUENCY (Hz)
10M
100M
Figure 33. Closed-Loop Output Impedance vs. Frequency
Figure 30. No Phase Reversal
60
VS = 5V
MARKER SET @ 10kHz
MARKER READING: 37.6nV/ Hz
TA = 25°C
TA = 25°C
50
15nV/DIV
40
30
20
0
1
2
3
4
SUPPLY VOLTAGE (V)
5
6
0
5
10
15
FREQUENCY (kHz)
Figure 34. Voltage Noise
Figure 31. Supply Current per Amplifier vs. Supply Voltage
Rev. E | Page 11 of 20
20
25
00935-034
0
00935-031
10
00935-033
1V
00935-030
200
SUPPLY CURRENT/AMPLIFIER (µA)
GAIN (dB)
VS = 5V
RL = NO LOAD
TA = 25°C
AD8541/AD8542/AD8544
THEORY OF OPERATION
Sourcing and sinking are strong at lower voltages, with 15 mA
available at 2.7 V and 18 mA at 3.0 V. For even higher output
currents, see the Analog Devices, Inc. AD8531/AD8532/AD8534
parts, with output currents to 250 mA. Information on these
parts is available from your Analog Devices representative, and
data sheets are available at www.analog.com.
NOTES ON THE AD854x AMPLIFIERS
The AD8541/AD8542/AD8544 amplifiers are improved
performance, general-purpose operational amplifiers.
Performance has been improved over previous amplifiers in
several ways.
Lower Supply Current for 1 MHz Gain Bandwidth
The AD854x series typically uses 45 μA of current per amplifier.
This is much less than the 200 μA to 700 μA used in earlier
generation parts with similar performance. This makes the
AD854x series a good choice for upgrading portable designs for
longer battery life. Alternatively, additional functions and
performance can be added at the same current drain.
Better Performance at Lower Voltages
The AD854x family of parts was designed to provide better ac
performance at 3.0 V and 2.7 V than previously available parts.
Typical gain-bandwidth product is close to 1 MHz at 2.7 V.
Voltage gain at 2.7 V and 3.0 V is typically 500,000. Phase
margin is typically over 60°C, making the part easy to use.
Higher Output Current
At 5 V single supply, the short-circuit current is typically 60 μA.
Even 1 V from the supply rail, the AD854x amplifiers can
provide a 30 mA output current, sourcing or sinking.
Rev. E | Page 12 of 20
AD8541/AD8542/AD8544
APPLICATIONS
The AD854x have very high open-loop gain (especially with a
supply voltage below 4 V), which makes it useful for active
filters of all types. For example, Figure 35 illustrates the AD8542
in the classic twin-T notch filter design. The twin-T notch is
desired for simplicity, low output impedance, and minimal use
of op amps. In fact, this notch filter can be designed with only
one op amp if Q adjustment is not required. Simply remove U2
as illustrated in Figure 36. However, a major drawback to this
circuit topology is ensuring that all the Rs and Cs closely match.
The components must closely match or notch frequency offset
and drift causes the circuit to no longer attenuate at the ideal
notch frequency. To achieve desired performance, 1% or better
component tolerances or special component screens are usually
required. One method to desensitize the circuit-to-component
mismatch is to increase R2 with respect to R1, which lowers Q.
A lower Q increases attenuation over a wider frequency range
but reduces attenuation at the peak notch frequency.
Figure 37 is an example of the AD8544 in a notch filter circuit.
The frequency dependent negative resistance (FNDR) notch
filter has fewer critical matching requirements than the twin-T
notch and for the FNDR Q is directly proportional to a single
resistor R1. While matching component values is still
important, it is also much easier and/or less expensive to
accomplish in the FNDR circuit. For example, the twin-T notch
uses three capacitors with two unique values, whereas the
FNDR circuit uses only two capacitors, which may be of the
same value. U3 is simply a buffer that is added to lower the
output impedance of the circuit.
R1
Q ADJUST
200Ω
2
C2
53.6µF
2.5VREF
2.5VREF
8
1/2 AD8542
U1
4
1
1/4 AD8544
1
C
26.7nF
f=
1/2 AD8542
7
U2
6
4 1–
R1
R1 + R2
2.5VREF
VIN
3
2
2C
7
6
VOUT
2.5VREF
C
00935-036
R/2
C
14
NC
COMPARATOR FUNCTION
AD8541
4
12
1/4 AD8544
U4
Figure 37. FNDR 60 Hz Notch Filter with Output Buffer
5.0V
R
13
2.5VREF
Figure 35. 60 Hz Twin-T Notch Filter, Q = 10
R
R
2.61kΩ
2.5VREF
R1
97.5kΩ
1
1
11
R
2.61kΩ
1
2π LC1
R2
2.5kΩ
5
2
1/4 AD8544
U1
R
2.61kΩ
5
L = R2C2
2πRC
f0 =
U2
6
4
3
C2
1µF
VOUT
R/2
50kΩ
C
26.7nF
VOUT
R
2.61kΩ
7
00935-035
f0 =
3
10
A comparator function is a common application for a spare op
amp in a quad package. Figure 38 illustrates ¼ of the AD8544 as
a comparator in a standard overload detection application.
Unlike many op amps, the AD854x family can double as
comparators because this op amp family has a rail-to-rail
differential input range, rail-to-rail output, and a great speed
vs. power ratio. R2 is used to introduce hysteresis. The AD854x,
when used as comparators, have 5 μs propagation delay at 5 V
and 5 μs overload recovery time.
R2
1MΩ
Figure 36. 60 Hz Twin-T Notch Filter, Q = ∞ (Ideal)
R1
1kΩ
VOUT
VIN
2.5VREF
2.5VDC
1/4 AD8541
00935-038
R
100kΩ
8
U3
C1
1µF
5.0V
R
100kΩ
1/4 AD8544
9
00935-037
NOTCH FILTER
Figure 38. AD854x Comparator Application—Overload Detector
Rev. E | Page 13 of 20
AD8541/AD8542/AD8544
C
100pF
PHOTODIODE APPLICATION
The AD854x family has very high impedance with an input bias
current typically around 4 pA. This characteristic allows the
AD854x op amps to be used in photodiode applications and
other applications that require high input impedance. Note that
the AD854x has significant voltage offset that can be removed
by capacitive coupling or software calibration.
•
Shielding the circuit.
•
Cleaning the circuit board.
•
Putting a trace connected to the noninverting input around
the inverting input.
•
Using separate analog and digital power supplies.
V+
OR
2
7
6
3
4
D
2.5VREF
2.5VREF
VOUT
AD8541
00935-039
Figure 39 illustrates a photodiode or current measurement
application. The feedback resistor is limited to 10 MΩ to avoid
excessive output offset. Also, note that a resistor is not needed
on the noninverting input to cancel bias current offset because
the bias current-related output offset is not significant when
compared to the voltage offset contribution. For best
performance, follow the standard high impedance layout
techniques, which include:
R
10MΩ
Figure 39. High Input Impedance Application—Photodiode Amplifier
Rev. E | Page 14 of 20
AD8541/AD8542/AD8544
OUTLINE DIMENSIONS
5.10
5.00
4.90
2.90 BSC
5
4
2.80 BSC
1.60 BSC
1
2
14
PIN 1
6.40
BSC
0.95 BSC
1
1.90
BSC
1.30
1.15
0.90
7
PIN 1
1.45 MAX
0.15 MAX
8
4.50
4.40
4.30
3
0.50
0.30
0.65
BSC
1.05
1.00
0.80
0.22
0.08
10°
5°
0°
SEATING
PLANE
1.20
MAX
0.15
0.05
0.60
0.45
0.30
0.30
0.19
0.20
0.09
SEATING
COPLANARITY
PLANE
0.10
0.75
0.60
0.45
8°
0°
COMPLIANT TO JEDEC STANDARDS MO-153-AB-1
COMPLIANT TO JEDEC STANDARDS MO-178-AA
Figure 40. 5-Lead Small Outline Transistor Package [SOT-23]
(RJ-5)
Dimensions shown in millimeters
Figure 41. 14-Lead Thin Shrink Small Outline Package [TSSOP]
(RU-14)
Dimensions shown in millimeters
8.75 (0.3445)
8.55 (0.3366)
1.35
1.25
1.15
5
1
4
2
3
PIN 1
1.10
0.80
0.30
0.15
SEATING
PLANE
8
14
1
7
1.27 (0.0500)
BSC
0.65 BSC
1.00
0.90
0.70
0.10 MAX
4.00 (0.1575)
3.80 (0.1496)
2.40
2.10
1.80
0.40
0.10
0.25 (0.0098)
0.10 (0.0039)
0.22
0.08
0.46
0.36
0.26
0.10 COPLANARITY
COMPLIANT TO JEDEC STANDARDS MO-203-AA
Figure 42. 5-Lead Thin Shrink Small Outline Transistor Package [SC70]
(KS-5)
Dimensions shown in millimeters
COPLANARITY
0.10
0.51 (0.0201)
0.31 (0.0122)
6.20 (0.2441)
5.80 (0.2283)
1.75 (0.0689)
1.35 (0.0531)
SEATING
PLANE
0.50 (0.0197)
0.25 (0.0098)
8°
0°
0.25 (0.0098)
0.17 (0.0067)
1.27 (0.0500)
0.40 (0.0157)
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 43. 14-Lead Standard Small Outline Package [SOIC_N]
Narrow Body
(R-14)
Dimensions shown in millimeters and (inches)
Rev. E | Page 15 of 20
45°
060606-A
2.20
2.00
1.80
AD8541/AD8542/AD8544
3.20
3.00
2.80
8
3.20
3.00
2.80
1
3.10
3.00
2.90
5
8
5.15
4.90
4.65
4.50
4.40
4.30
4
1
PIN 1
0.65 BSC
0.95
0.85
0.75
0.38
0.22
COPLANARITY
0.10
6.40 BSC
4
PIN 1
0.65 BSC
1.10 MAX
0.15
0.00
5
0.23
0.08
0.15
0.05
0.80
0.60
0.40
8°
0°
1.20
MAX
COPLANARITY
0.10
SEATING
PLANE
0.30
0.19
SEATING 0.20
PLANE
0.09
8°
0°
0.75
0.60
0.45
COMPLIANT TO JEDEC STANDARDS MO-153-AA
COMPLIANT TO JEDEC STANDARDS MO-187-AA
Figure 44. 8-Lead Mini Small Outline Package [MSOP]
(RM-8)
Dimensions shown in millimeters
Figure 45. 8-Lead Thin Shrink Small Outline Package [TSSOP]
(RU-8)
Dimensions shown in millimeters
5.00 (0.1968)
4.80 (0.1890)
8
1
5
4
1.27 (0.0500)
BSC
0.25 (0.0098)
0.10 (0.0040)
COPLANARITY
0.10
SEATING
PLANE
6.20 (0.2440)
5.80 (0.2284)
1.75 (0.0688)
1.35 (0.0532)
0.51 (0.0201)
0.31 (0.0122)
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)
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 46. 8-Lead Standard Small Outline Package [SOIC_N]
Narrow Body
(R-8)
Dimensions shown in millimeters and (inches)
Rev. E | Page 16 of 20
060506-A
4.00 (0.1574)
3.80 (0.1497)
AD8541/AD8542/AD8544
ORDERING GUIDE
Model
AD8541AKS-R2
AD8541AKS-REEL7
AD8541AKSZ-R21
AD8541AKSZ-REEL71
AD8541AR
AD8541AR-REEL
AD8541AR-REEL7
AD8541ARZ1
AD8541ARZ-REEL1
AD8541ARZ-REEL71
AD8541ART-R2
AD8541ART-REEL
AD8541ART-REEL7
AD8541ARTZ-R21
AD8541ARTZ-REEL1
AD8541ARTZ-REEL71
AD8542AR
AD8542AR-REEL
AD8542AR-REEL7
AD8542ARZ1
AD8542ARZ-REEL1
AD8542ARZ-REEL71
AD8542ARM-R2
AD8542ARM-REEL
AD8542ARMZ-R21
AD8542ARMZ-REEL1
AD8542ARU
AD8542ARU-REEL
AD8542ARUZ1
AD8542ARUZ-REEL1
AD8544AR
AD8544AR-REEL
AD8544AR-REEL7
AD8544ARZ1
AD8544ARZ-REEL1
AD8544ARZ-REEL71
AD8544ARU
AD8544ARU-REEL
AD8544ARUZ1
AD8544ARUZ-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
–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 SC70
5-Lead SC70
5-Lead SC70
5-Lead SC70
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
5-Lead SOT-23
5-Lead SOT-23
5-Lead SOT-23
5-Lead SOT-23
5-Lead SOT-23
5-Lead SOT-23
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 MSOP
8-Lead MSOP
8-Lead MSOP
8-Lead MSOP
8-Lead TSSOP
8-Lead TSSOP
8-Lead TSSOP
8-Lead TSSOP
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; # denotes lead-free product, may be top or bottom marked.
Rev. E | Page 17 of 20
Package
Option
KS-5
KS-5
KS-5
KS-5
R-8
R-8
R-8
R-8
R-8
R-8
RJ-5
RJ-5
RJ-5
RJ-5
RJ-5
RJ-5
R-8
R-8
R-8
R-8
R-8
R-8
RM-8
RM-8
RM-8
RM-8
RU-8
RU-8
RU-8
RU-8
R-14
R-14
R-14
R-14
R-14
R-14
RU-14
RU-14
RU-14
RU-14
Branding
A4B
A4B
A12
A12
A4A
A4A
A4A
A4A#
A4A#
A4A#
AVA
AVA
AVA#
AVA#
AD8541/AD8542/AD8544
NOTES
Rev. E | Page 18 of 20
AD8541/AD8542/AD8544
NOTES
Rev. E | Page 19 of 20
AD8541/AD8542/AD8544
NOTES
©2007 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
C00935-0-1/07(E)
Rev. E | Page 20 of 20