2
1
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
OUT A
AD8541
V–
+IN A
V+
4
5
00935-001
–IN A
3
Rail-to-rail input and output Qualified for automotive applications
Figure 1. 5-Lead SC70 and 5-Lead SOT-23 (KS and RJ Suffixes)
ASIC input or output amplifiers Sensor interfaces
Piezoelectric transducer amplifiers Medical instrumentation
Mobile communications Audio outputs
NC
–IN A
+IN A V–
AD8541
2
7
3
6
4
5
8
1
NC = NO CONNECT
NC V+
00935-002
OUT A NC
Portable systems
The AD8541/AD8542/AD8544 are single, dual, and quad rail- to-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
OUT A
–IN A
+IN A
Figure 2. 8-Lead SOIC
(R Suffix)
8
1
AD8542
2
7
3
6
V+ OUT B
–IN B
of 45 μA per amplifier.
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
V– +IN B
1
5
4
00935-003
Figure 3. 8-Lead SOIC, 8-Lead MSOP, and 8-Lead TSSOP (R, RM, and RU Suffixes)
2
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,
OUT A
–IN A
4
+IN A
OUT D
13
14
–IN D
11
AD8544
12
+IN D
5
3
making them useful for active filters and gain stages.
V+ V–
The AD8541/AD8542/AD8544 are specified over the extended industrial temperature range (–40°C to +125°C). The AD8541
+IN B
–IN B
+IN C
9
10
–IN C
is available in 5-lead SOT-23, 5-lead SC70, and 8-lead SOIC 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. See the Ordering Guide for automotive models.
8
7
6
00935-004
OUT B OUT C
Figure 4. 14-Lead SOIC and 14-Lead TSSOP (R and RU Suffixes)
Rev. G
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibilityis assumedby AnalogDevices foritsuse, norforanyinfringements of patents or other rightsofthirdpartiesthatmayresultfromitsuse.Specificationssubjecttochangewithoutnotice.No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarksandregisteredtrademarksarethepropertyoftheirrespectiveowners.
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 ©2008–2011 Analog Devices, Inc. All rights reserved.
Typical Performance Characteristics 7
Notes on the AD854x Amplifiers 13
6/11—Rev. F to Rev. G
Changes to Features Section and General Description
Section 1
Changes to Table 5 6
Updated Outline Dimensions 16
Changes to Ordering Guide 19
Added Automotive Products Section 19
1/08—Rev. E to Rev. F
Inserted Figure 21; Renumbered Sequentially 9
Changes to Figure 22 Caption 9
Changes to Notch Filter Section, Figure 35, Figure 36, and Figure 37 13
Updated Outline Dimensions 16
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
VS = 2.7 V, VCM = 1.35 V, TA = 25°C, unless otherwise noted.
Table 1.
Parameter | Symbol | Conditions | Min | Typ | Max | Unit |
INPUT CHARACTERISTICS | ||||||
Offset Voltage | VOS | 1 | 6 | mV | ||
−40°C ≤ TA ≤ +125°C | 7 | mV | ||||
Input Bias Current | IB | 4 | 60 | pA | ||
−40°C ≤ TA ≤ +85°C | 100 | pA | ||||
−40°C ≤ TA ≤ +125°C | 1000 | pA | ||||
Input Offset Current | IOS | 0.1 | 30 | pA | ||
−40°C ≤ TA ≤ +85°C | 50 | pA | ||||
−40°C ≤ TA ≤ +125°C | 500 | pA | ||||
Input Voltage Range | 0 | 2.7 | V | |||
Common-Mode Rejection Ratio | CMRR | VCM = 0 V to 2.7 V | 40 | 45 | dB | |
−40°C ≤ TA ≤ +125°C | 38 | dB | ||||
Large Signal Voltage Gain | AVO | RL = 100 kΩ, VO = 0.5 V to 2.2 V | 100 | 500 | V/mV | |
−40°C ≤ TA ≤ +85°C | 50 | V/mV | ||||
−40°C ≤ TA ≤ +125°C | 2 | V/mV | ||||
Offset Voltage Drift | ΔVOS/ΔT | −40°C ≤ TA ≤ +125°C | 4 | μV/°C | ||
Bias Current Drift | ΔIB/ΔT | −40°C ≤ TA ≤ +85°C | 100 | fA/°C | ||
−40°C ≤ TA ≤ +125°C | 2000 | fA/°C | ||||
Offset Current Drift | ΔIOS/ΔT | −40°C ≤ TA ≤ +125°C | 25 | fA/°C | ||
OUTPUT CHARACTERISTICS | ||||||
Output Voltage High | VOH | IL = 1 mA | 2.575 | 2.65 | V | |
−40°C ≤ TA ≤ +125°C | 2.550 | V | ||||
Output Voltage Low | VOL | IL = 1 mA | 35 | 100 | mV | |
−40°C ≤ TA ≤ +125°C | 125 | mV | ||||
Output Current | IOUT | VOUT = VS − 1 V | 15 | mA | ||
ISC | ±20 | mA | ||||
Closed-Loop Output Impedance | ZOUT | f = 200 kHz, AV = 1 | 50 | Ω | ||
POWER SUPPLY | VS = 2.5 V to 6 V −40°C ≤ TA ≤ +125°C VO = 0 V −40°C ≤ TA ≤ +125°C | dB dB μA μA | ||||
Power Supply Rejection Ratio Supply Current/Amplifier | PSRR ISY | 65 60 | 76 38 | 55 75 | ||
DYNAMIC PERFORMANCE | ||||||
Slew Rate | SR | RL = 100 kΩ | 0.4 | 0.75 | V/μs | |
Settling Time | tS | To 0.1% (1 V step) | 5 | μs | ||
Gain Bandwidth Product | GBP | 980 | kHz | |||
Phase Margin | 63 | Degrees | ||||
ΦM | ||||||
NOISE PERFORMANCE | ||||||
Voltage Noise Density | en | f = 1 kHz | 40 | nV/√Hz | ||
en | f = 10 kHz | 38 | nV/√Hz | |||
Current Noise Density | in | <0.1 | pA/√Hz |
VS = 3.0 V, VCM = 1.5 V, TA = 25°C, unless otherwise noted.
Table 2.
Parameter | Symbol | Conditions | Min | Typ | Max | Unit |
INPUT CHARACTERISTICS | ||||||
Offset Voltage | VOS | 1 | 6 | mV | ||
−40°C ≤ TA ≤ +125°C | 7 | mV | ||||
Input Bias Current | IB | 4 | 60 | pA | ||
−40°C ≤ TA ≤ +85°C | 100 | pA | ||||
−40°C ≤ TA ≤ +125°C | 1000 | pA | ||||
Input Offset Current | IOS | 0.1 | 30 | pA | ||
−40°C ≤ TA ≤ +85°C | 50 | pA | ||||
−40°C ≤ TA ≤ +125°C | 500 | pA | ||||
Input Voltage Range | 0 | 3 | V | |||
Common-Mode Rejection Ratio | CMRR | VCM = 0 V to 3 V | 40 | 45 | dB | |
−40°C ≤ TA ≤ +125°C | 38 | dB | ||||
Large Signal Voltage Gain | AVO | RL = 100 kΩ, VO = 0.5 V to 2.2 V | 100 | 500 | V/mV | |
−40°C ≤ TA ≤ +85°C | 50 | V/mV | ||||
−40°C ≤ TA ≤ +125°C | 2 | V/mV | ||||
Offset Voltage Drift | ΔVOS/ΔT | −40°C ≤ TA ≤ +125°C | 4 | μV/°C | ||
Bias Current Drift | ΔIB/ΔT | −40°C ≤ TA ≤ +85°C | 100 | fA/°C | ||
−40°C ≤ TA ≤ +125°C | 2000 | fA/°C | ||||
Offset Current Drift | ΔIOS/ΔT | −40°C ≤ TA ≤ +125°C | 25 | fA/°C | ||
OUTPUT CHARACTERISTICS | ||||||
Output Voltage High | VOH | IL = 1 mA | 2.875 | 2.955 | V | |
−40°C ≤ TA ≤ +125°C | 2.850 | V | ||||
Output Voltage Low | VOL | IL = 1 mA | 32 | 100 | mV | |
−40°C ≤ TA ≤ +125°C | 125 | mV | ||||
Output Current | IOUT | VOUT = VS − 1 V | 18 | mA | ||
ISC | ±25 | mA | ||||
Closed-Loop Output Impedance | ZOUT | f = 200 kHz, AV = 1 | 50 | Ω | ||
POWER SUPPLY Power Supply Rejection Ratio Supply Current/Amplifier | PSRR ISY | VS = 2.5 V to 6 V −40°C ≤ TA ≤ +125°C VO = 0 V −40°C ≤ TA ≤ +125°C | 65 60 | 76 40 | 60 75 | dB dB μA μA |
DYNAMIC PERFORMANCE | ||||||
Slew Rate | SR | RL = 100 kΩ | 0.4 | 0.8 | V/μs | |
Settling Time | tS | To 0.01% (1 V step) | 5 | μs | ||
Gain Bandwidth Product | GBP | 980 | kHz | |||
Phase Margin | ΦM | 64 | Degrees | |||
NOISE PERFORMANCE | ||||||
Voltage Noise Density | en | f = 1 kHz | 42 | nV/√Hz | ||
en | f = 10 kHz | 38 | nV/√Hz | |||
Current Noise Density | in | <0.1 | pA/√Hz |
VS = 5.0 V, VCM = 2.5 V, TA = 25°C, unless otherwise noted.
Table 3.
Parameter | Symbol | Conditions | Min | Typ | Max | Unit |
INPUT CHARACTERISTICS | ||||||
Offset Voltage | VOS | 1 | 6 | mV | ||
−40°C ≤ TA ≤ +125°C | 7 | mV | ||||
Input Bias Current | IB | 4 | 60 | pA | ||
−40°C ≤ TA ≤ +85°C | 100 | pA | ||||
−40°C ≤ TA ≤ +125°C | 1000 | pA | ||||
Input Offset Current | IOS | 0.1 | 30 | pA | ||
−40°C ≤ TA ≤ +85°C | 50 | pA | ||||
−40°C ≤ TA ≤ +125°C | 500 | pA | ||||
Input Voltage Range | 0 | 5 | V | |||
Common-Mode Rejection Ratio | CMRR | VCM = 0 V to 5 V | 40 | 48 | dB | |
−40°C ≤ TA ≤ +125°C | 38 | dB | ||||
Large Signal Voltage Gain | AVO | RL = 100 kΩ, VO = 0.5 V to 2.2 V | 20 | 40 | V/mV | |
−40°C ≤ TA ≤ +85°C | 10 | V/mV | ||||
−40°C ≤ TA ≤ +125°C | 2 | V/mV | ||||
Offset Voltage Drift | ΔVOS/ΔT | −40°C ≤ TA ≤ +125°C | 4 | μV/°C | ||
Bias Current Drift | ΔIB/ΔT | −40°C ≤ TA ≤ +85°C | 100 | fA/°C | ||
−40°C ≤ TA ≤ +125°C | 2000 | fA/°C | ||||
Offset Current Drift | ΔIOS/ΔT | −40°C ≤ TA ≤ +125°C | 25 | fA/°C | ||
OUTPUT CHARACTERISTICS | ||||||
Output Voltage High | VOH | IL = 1 mA | 4.9 | 4.965 | V | |
−40°C ≤ TA ≤ +125°C | 4.875 | V | ||||
Output Voltage Low | VOL | IL = 1 mA | 25 | 100 | mV | |
−40°C ≤ TA ≤ +125°C | 125 | mV | ||||
Output Current | IOUT | VOUT = VS − 1 V | 30 | mA | ||
ISC | ±60 | mA | ||||
Closed-Loop Output Impedance | ZOUT | f = 200 kHz, AV = 1 | 45 | Ω | ||
POWER SUPPLY | VS = 2.5 V to 6 V −40°C ≤ TA ≤ +125°C VO = 0 V −40°C ≤ TA ≤ +125°C | dB dB μA μA | ||||
Power Supply Rejection Ratio Supply Current/Amplifier | PSRR ISY | 65 60 | 76 45 | 65 85 | ||
DYNAMIC PERFORMANCE | ||||||
Slew Rate | SR | RL = 100 kΩ, CL = 200 pF | 0.45 | 0.92 | V/μs | |
Full Power Bandwidth | BWP | 1% distortion | 70 | kHz | ||
Settling Time | tS | To 0.1% (1 V step) | 6 | μs | ||
Gain Bandwidth Product | GBP | 1000 | kHz | |||
Phase Margin | ΦM | 67 | Degrees | |||
NOISE PERFORMANCE | ||||||
Voltage Noise Density | en | f = 1 kHz | 42 | nV/√Hz | ||
en | f = 10 kHz | 38 | nV/√Hz | |||
Current Noise Density | in | <0.1 | pA/√Hz |
Parameter | Rating |
Supply Voltage (VS) | 6 V |
Input Voltage | GND to VS |
±6 V | |
Storage Temperature Range | −65°C to +150°C |
Operating Temperature Range | −40°C to +125°C |
Junction Temperature Range | −65°C to +150°C |
Lead Temperature (Soldering, 60 sec) | 300°C |
1 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 and measured using a standard 4-layer board, unless otherwise specified.
Table 5.
Package Type | θJA | θJC | Unit |
5-Lead SC70 (KS) | 376 | 126 | °C/W |
5-Lead SOT-23 (RJ) | 190 | 92 | °C/W |
8-Lead SOIC (R) | 120 | 45 | °C/W |
8-Lead MSOP (RM) | 142 | 45 | °C/W |
8-Lead TSSOP (RU) | 240 | 43 | °C/W |
14-Lead SOIC (R) | 115 | 36 | °C/W |
14-Lead TSSOP (RU) | 112 | 35 | °C/W |
180
VS = 5V
400
VS = 2.7V AND 5V
160
NUMBER OF AMPLIFIERS
140
120
100
80
60
40
00935-005
20
VCM = 2.5V TA = 25°C
350
INPUT BIAS CURRENT (pA)
300
250
200
150
100
50
VCM = VS/2
0
–4.5 –3.5
–2.5 –1.5 –0.5 0.5
1.5 2.5 3.5
4.5
0
00935-008
–40 –20 0 20 40 60 80 100 120 140
INPUT OFFSET VOLTAGE (mV)
Figure 5. Input Offset Voltage Distribution
TEMPERATURE (°C)
Figure 8. Input Bias Current vs. Temperature
1.0
0.5
INPUT OFFSET VOLTAGE (mV)
0
–0.5
–1.0
VS = 2.7V AND 5V VCM = VS/2
7
VS = 2.7V AND 5V
INPUT OFFSET CURRENT (pA)
6 VCM = VS/2 5
4
–1.5
–2.0
–2.5
–3.0
–3.5
–4.0
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
145
3
2
1
0
00935-009
–1
–55 –35 –15 5 25 45 65 85 105 125 145
TEMPERATURE (°C)
00935-006
Figure 6. Input Offset Voltage vs. Temperature Figure 9. Input Offset Current vs. Temperature
9
VS = 2.7V AND 5V
8 VCM = VS/2
INPUT BIAS CURRENT (pA)
7
6
5
4
3
2
1
0
160
140
POWER SUPPLY REJECTION (dB)
120
100
80
60
40
20
0
–20
–40
VS = 2.7V TA = 25°C
00935-007
+PSRR
–PSRR
–0.5 0.5 1.5 2.5 3.5 4.5 5.5
COMMON-MODE VOLTAGE (V)
Figure 7. Input Bias Current vs. Common-Mode Voltage
100 1k 10k 100k 1M 10M FREQUENCY (Hz)
00935-010
Figure 10. Power Supply Rejection vs. Frequency
10k
1k
VS = 2.7V TA = 25°C
60
VS = 2.7V RL = 10kΩ
SMALL SIGNAL OVERSHOOT (%)
50 TA = 25°C
∆ OUTPUT VOLTAGE (mV)
100
10
1
0.1
SOURCE
SINK
40 +OS
30 –OS
20
00935-011
10
0.01
0.001 0.01 0.1 1 10 100
LOAD CURRENT (mA)
Figure 11. Output Voltage to Supply Rail vs. Load Current
0
00935-014
10 100 1k 10k CAPACITANCE (pF)
Figure 14. Small Signal Overshoot vs. Load Capacitance
3.0
2.5
VS = 2.7V
VIN = 2.5V p-p RL = 2kΩ
TA = 25°C
60
VS = 2.7V RL = 2kΩ
SMALL SIGNAL OVERSHOOT (%)
50 TA = 25°C
OUTPUT SWING (V p-p)
2.0 40
1.5
1.0
0.5
+OS
30
–OS
20
10
0
1k 10k 100k 1M 10M
FREQUENCY (Hz)
0
00935-015
10 100 1k 10k CAPACITANCE (pF)
00935-012
Figure 12. Closed-Loop Output Voltage Swing vs. Frequency Figure 15. Small Signal Overshoot vs. Load Capacitance
60
VS = 2.7V RL = ∞
SMALL SIGNAL OVERSHOOT (%)
50 TA = 25°C
40
30
20
10
+OS
–OS
00935-013
1.35V
VS = 2.7V RL = 100kΩ CL = 300pF AV = 1
TA = 25°C
0
10 100 1k 10k CAPACITANCE (pF)
Figure 13. Small Signal Overshoot vs. Load Capacitance
50mV 10µs
00935-016
Figure 16. Small Signal Transient Response
1.35V
VS = 2.7V RL = 2kΩ AV = 1 TA = 25°C | |||||||||
500mV | 10µs |
00935-017
Figure 17. Large Signal Transient Response
90
80
COMMON-MODE REJECTION (dB)
70
60
50
40
30
20
10
0
–10
VS = 5V TA = 25°C
00935-020
1k 10k 100k 1M 10M FREQUENCY (Hz)
Figure 20. Common-Mode Rejection vs. Frequency
VS = 2.7V
RL = NO LOAD TA = 25°C
80
GAIN (dB)
60
40
20
0
45
PHASE SHIFT (Degrees)
90
135
180
5
VS = 5V
INPUT OFFSET VOLTAGE (mV)
4 RL = NO LOAD TA = 25°C
3
2
1
0
–1
–2
–3
00935-018
1k 10k 100k 1M 10M FREQUENCY (Hz)
Figure 18. Open-Loop Gain and Phase vs. Frequency
–4
00935-040
–5
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
COMMON-MODE VOLTAGE (V)
Figure 21. Input Offset Voltage vs. Common-Mode Voltage
160
POWER SUPPLY REJECTION RATIO (dB)
140
120
100
80
60
40
20
0
–20
–40
VS = 5V TA = 25°C
–PSRR
+PSRR
10k
∆ OUTPUT VOLTAGE (mV)
1k
100
10
1
0.1
00935-021
0.01
VS = 5V TA = 25°C
SOURCE
00935-019
SINK
100 1k 10k 100k 1M 10M FREQUENCY (Hz)
Figure 19. Power Supply Rejection Ratio vs. Frequency
0.001 0.01 0.1 1 10 100
LOAD CURRENT (mA)
Figure 22. Output Voltage to Supply Rail vs. Load Current
5.0
4.5
4.0
OUTPUT SWING (V p-p)
3.5
3.0
2.5
2.0
1.5
60
VS = 5V RL = 2kΩ
SMALL SIGNAL OVERSHOOT (%)
50 TA = 25°C
40
30
20
+OS
–OS
1.0
0.5
0
VS = 5V VIN = 4.9V p-p RL = NO LOAD TA = 25°C | |||||||||||||||||||||||||
1k 10k 100k 1M 10M FREQUENCY (Hz)
10
00935-025
0
10 100 1k 10k CAPACITANCE (pF)
00935-022
Figure 23. Closed-Loop Output Voltage Swing vs. Frequency, Figure 26. Small Signal Overshoot vs. Load Capacitance
5.0
4.5
4.0
OUTPUT SWING (V p-p)
3.5
3.0
2.5
2.0
1.5
1.0
0.5
VS = 5V
VIN = 4.9V p-p RL = 2kΩ
TA = 25°C
60
VS = 5V RL = ∞
SMALL SIGNAL OVERSHOOT (%)
50 TA = 25°C
40
30
20
10
+OS
–OS
0
1k 10k 100k 1M 10M
FREQUENCY (Hz)
0
00935-026
10 100 1k 10k CAPACITANCE (pF)
00935-023
Figure 24. Closed-Loop Output Voltage Swingvs. Frequency Figure 27. Small Signal Overshoot vs. Load Capacitance
60
VS = 5V RL = 10kΩ
SMALL SIGNAL OVERSHOOT (%)
50 TA = 25°C
40
30
20
10
+OS
00935-024
–OS
2.5V
VS = 5V
RL = 100kΩ CL = 300pF AV = 1
TA = 25°C
0
10 100 1k 10k CAPACITANCE (pF)
Figure 25. Small Signal Overshoot vs. Load Capacitance
50mV 10µs
00935-027
Figure 28. Small Signal Transient Response
2.5V
VS = 5V RL = 2kΩ AV = 1 TA = 25°C | |||||||||
1V | 10µs |
00935-028
Figure 29. Large Signal Transient Response
2.5V
VIN VOUT
VS = 5V RL = 10kΩ AV = 1
TA = 25°C
00935-030
1V 20µs
Figure 31. No Phase Reversal
VS = 5V
RL = NO LOAD TA = 25°C
80
GAIN (dB)
60
40
20
0
45
PHASE SHIFT (Degrees)
90
135
180
60
TA = 25°C
SUPPLY CURRENT/AMPLIFIER (µA)
50
40
30
20
00935-029
10
1k 10k 100k 1M 10M FREQUENCY (Hz)
Figure 30. Open-Loop Gain and Phase vs. Frequency
0
00935-031
0 1 2 3 4 5 6
SUPPLY VOLTAGE (V)
Figure 32. Supply Current per Amplifier vs. Supply Voltage
55
SUPPLY CURRENT/AMPLIFIER (µA)
50
VS = 5V
45
40
VS = 2.7V
35
30
25
20
–55 –35 –15 5 25 45 65 85 105 125 145
TEMPERATURE (°C)
Figure 33. Supply Current per Amplifier vs. Temperature
VS = 5V
15nV/DIV
MARKER SET @ 10kHz MARKER READING: 37.6nV/ Hz TA = 25°C
00935-034
0 5 10 15 20 25
FREQUENCY (kHz)
Figure 35. Voltage Noise
00935-032
VS = 2.7V AND 5V AV = 1 TA = 25°C | |||||||||||||||||||||||||
1000
900
800
IMPEDANCE (Ω)
700
600
500
400
300
200
100
00935-033
0
1k 10k 100k 1M 10M 100M FREQUENCY (Hz)
Figure 34. Closed-Loop Output Impedance vs. Frequency
The AD8541/AD8542/AD8544 amplifiers are improved performance, general-purpose operational amplifiers. Performance has been improved over previous amplifiers in several ways, including lower supply current for 1 MHz gain bandwidth, higher output current, and better performance at lower voltages.
Lower Supply Current for 1 MHz Gain Bandwidth
The AD854x series typically uses 45 μA of current per amplifier, which 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.
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.
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 AD8531/AD8532/AD8534 parts for output currents to 250 mA. Information on these parts is available from your Analog Devices, Inc. representative, and data sheets are available at www.analog.com.
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.
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 36 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 37. However, a major drawback to this circuit topology is ensuring that all the Rs and Cs closely match.
Figure 38 is an example of the AD8544 in a notch filter circuit. The frequency dependent negative resistance (FDNR) notch filter has fewer critical matching requirements than the twin-T notch, where as the Q of the FDNR is directly proportional to a single resistor R1. Although matching component values is still important, it is also much easier and/or less expensive to accomplish in the FDNR circuit. For example, the twin-T notch uses three capacitors with two unique values, whereas the FDNR 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.
The components must closely match or notch frequency offset
R1 9
1/4 AD8544
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.
VIN
2.5V
REF
Q ADJUST 8
200Ω 10 U3
C1
1µF
R
VOUT
A lower Q increases attenuation over a wider frequency range but reduces attenuation at the peak notch frequency.
5.0V
1/4 AD8544
6
7
U2 5
2.61kΩ
C2 1µF
R 2.61kΩ
3 4
2 U1
1/4 AD8544
1
11
R 100kΩ
R 100kΩ
3 8 1/2 AD8542
R
1 2.61kΩ
VIN
2.5VREF
2C
53.6µF
R/2 50kΩ
U1 VOUT
2 1
4
VIN
f =
2π LC1
L = R2C2
R 2.61kΩ
2.5VREF
13 1/4 AD8544
U4
14
12 NC
f0 = 1
2πRC
f0 =
C 26.7nF
1
R1
C 26.7nF
1/2 AD8542 5
7
U2 6
R2 2.5kΩ
00935-035
R1 97.5kΩ
2.5VREF
00935-037
Figure 38. FDNR 60 Hz Notch Filter with Output Buffer
A comparator function is a common application for a spare op
4 1 – R1 + R2
2.5V
REF
amp in a quad package. Figure 39 illustrates ¼ of the AD8544 as a
Figure 36. 60 Hz Twin-T Notch Filter, Q = 10
5.0V
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.
R R
2C
VIN
R/2
2.5VREF
3 7
2 U1
AD8541
6
4
VOUT
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
00935-036
C C VIN
R1
1kΩ
VOUT
Figure 37. 60 Hz Twin-T Notch Filter, Q = ∞ (Ideal)
2.5VREF
2.5VDC
1/4 AD8541
00935-038
Figure 39. AD854x Comparator Application—Overload Detector
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
OR 2
3
C 100pF
R 10MΩ
V+
7
6 VOUT
by capacitive coupling or software calibration.
Figure 40 illustrates a photodiode or current measurement application. The feedback resistor is limited to 10 MΩ to avoid
D
2.5VREF
VREF
4 AD8541
00935-039
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.
Figure 40. High Input Impedance Application—Photodiode Amplifier
3.00
2.90
2.80
1.70
1.60
1.50
5
4
1 2 3
3.00
2.80
2.60
1.30
1.15
0.90
1.90 BSC
0.95 BSC
1.45 MAX
0.95 MIN
0.20 MAX
0.08 MIN
0.55
0.15 MAX
0.05 MIN
0.50 MAX
0.35 MIN
SEATING PLANE
10°
5°
0°
0.60
BSC
0.45
0.35
11-01-2010-A
COMPLIANT TO JEDEC STANDARDS MO-178-AA
Figure 41. 5-Lead Small Outline Transistor Package [SOT-23] (RJ-5)
Dimensions shown in millimeters
5.10
5.00
4.90
4.50
4.40
4.30
14 8
6.40
BSC
1 7
PIN 1
0.65 BSC
1.05
1.00 1.20
MAX
0.80
0.20
0.09 0.75
0.15
0.05 0.30
8°
SEATING 0°
PLANE
0.60
0.45
COPLANARITY 0.10
0.19
061908-A
COMPLIANT TO JEDEC STANDARDS MO-153-AB-1
Figure 42. 14-Lead Thin Shrink Small Outline Package [TSSOP] (RU-14)
Dimensions shown in millimeters
2.20
2.00
1.80
1.35
1.25
1.15
5
1 2 3
2.40
4
2.10
1.80
1.00
0.65 BSC
1.10
0.40
0.90
0.70
0.80
SEATING
0.10
0.22
0.46
0.10 MAX
COPLANARITY 0.10
0.30
0.15
PLANE
0.08
0.36
0.26
072809-A
COMPLIANT TO JEDEC STANDARDS MO-203-AA
Figure 43. 5-Lead Thin Shrink Small Outline Transistor Package [SC70] (KS-5)
Dimensions shown in millimeters
8.75 (0.3445)
8.55 (0.3366)
4.00 (0.1575)
3.80 (0.1496)
6.20 (0.2441)
7
8
14
1
5.80 (0.2283)
0.25 (0.0098)
0.10 (0.0039) COPLANARITY
1.27 (0.0500) BSC
0.10 PLANE 0.25 (0.0098) | |||
0.31 (0.0122) | 0.17 (0.0067) |
0.51 (0.0201)
1.75 (0.0689)
1.35 (0.0531) SEATING
0.50 (0.0197)
0.25 (0.0098)
8°
0°
1.27 (0.0500)
0.40 (0.0157)
45°
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 44. 14-Lead Standard Small Outline Package [SOIC_N]
Narrow Body (R-14)
Dimensions shown in millimeters and (inches)
3.20
3.00
2.80
3.10
3.00
2.90
3.20
3.00
2.80
8 5 5.15
4.90
4.65
1 4
8 5
4.50
4.40
4.30
6.40 BSC
PIN 1 1 4
IDENTIFIER
0.95
0.65 BSC
15° MAX
PIN 1
0.65 BSC
0.15
0.85
1.10 MAX
0.05
1.20
0.75
MAX
8°
0.15
0.05
10-07-2009-B
COPLANARITY
0.40
0.25
6° 0.23
0° 0.09
0.80
0.55
0.40
COPLANARITY 0.10
0.30
0.19
SEATING PLANE
0.20 0° 0.09
0.75
0.60
0.45
0.10 COMPLIANT TO JEDEC STANDARDS MO-153-AA
COMPLIANT TO JEDEC STANDARDS MO-187-AA
Figure 45. 8-Lead Mini Small Outline Package [MSOP] (RM-8)
Dimensions shown in millimeters
Figure 46. 8-Lead Thin Shrink Small Outline Package [TSSOP] (RU-8)
Dimensions shown in millimeters
5.00 (0.1968)
4.80 (0.1890)
4.00 (0.1574)
3.80 (0.1497)
8
5
6.20 (0.2441)
4
1
5.80 (0.2284)
1.27 (0.0500) 0.50 (0.0196)
45°
0.25 (0.0098)
0.10 (0.0040)
BSC
1.75 (0.0688)
1.35 (0.0532) 8°
0°
0.25 (0.0099)
COPLANARITY
0.51 (0.0201)
1.27 (0.0500)
0.10
SEATING PLANE
0.31 (0.0122)
0.25 (0.0098)
0.17 (0.0067)
0.40 (0.0157)
COMPLIANT TO JEDEC STANDARDS MS-012-AA
012407-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 47. 8-Lead Standard Small Outline Package [SOIC_N]
Narrow Body (R-8)
Dimensions shown in millimeters and (inches)
Temperature Range | Package Description | Package Option | Branding | |
AD8541AKSZ-R2 | –40°C to +125°C | 5-Lead SC70 | KS-5 | A12 |
AD8541AKSZ-REEL7 | –40°C to +125°C | 5-Lead SC70 | KS-5 | A12 |
AD8541ARTZ-R2 | –40°C to +125°C | 5-Lead SOT-23 | RJ-5 | A4A |
AD8541ARTZ-REEL | –40°C to +125°C | 5-Lead SOT-23 | RJ-5 | A4A |
AD8541ARTZ-REEL7 | –40°C to +125°C | 5-Lead SOT-23 | RJ-5 | A4A |
AD8541ARZ | –40°C to +125°C | 8-Lead SOIC_N | R-8 | |
AD8541ARZ-REEL | –40°C to +125°C | 8-Lead SOIC_N | R-8 | |
AD8541ARZ-REEL7 | –40°C to +125°C | 8-Lead SOIC_N | R-8 | |
AD8542ARZ | –40°C to +125°C | 8-Lead SOIC_N | R-8 | |
AD8542ARZ-REEL | –40°C to +125°C | 8-Lead SOIC_N | R-8 | |
AD8542ARZ-REEL7 | –40°C to +125°C | 8-Lead SOIC_N | R-8 | |
AD8542ARM-REEL | –40°C to +125°C | 8-Lead MSOP | RM-8 | AVA |
AD8542ARMZ | –40°C to +125°C | 8-Lead MSOP | RM-8 | AVA |
AD8542ARMZ-REEL | –40°C to +125°C | 8-Lead MSOP | RM-8 | AVA |
AD8542ARU-REEL | –40°C to +125°C | 8-Lead TSSOP | RU-8 | |
AD8542ARUZ | –40°C to +125°C | 8-Lead TSSOP | RU-8 | |
AD8542ARUZ-REEL | –40°C to +125°C | 8-Lead TSSOP | RU-8 | |
AD8544ARZ | –40°C to +125°C | 14-Lead SOIC_N | R-14 | |
AD8544ARZ-REEL | –40°C to +125°C | 14-Lead SOIC_N | R-14 | |
AD8544ARZ-REEL7 | –40°C to +125°C | 14-Lead SOIC_N | R-14 | |
AD8544ARUZ | –40°C to +125°C | 14-Lead TSSOP | RU-14 | |
AD8544ARUZ-REEL | –40°C to +125°C | 14-Lead TSSOP | RU-14 | |
AD8544WARZ-RL | –40°C to +125°C | 14-Lead SOIC_N | R-14 | |
AD8544WARZ-R7 | –40°C to +125°C | 14-Lead SOIC_N | R-14 |
1 Z = RoHS Compliant Part.
2 W = Qualified for Automotive Applications.
The AD8544W models are available with controlled manufacturing to support the quality and reliability requirements of automotive applications. Note that these automotive models may have specifications that differ from the commercial models; therefore, designers should review the Specifications section of this data sheet carefully. Only the automotive grade products shown are available for use in automotive applications. Contact your local Analog Devices account representative for specific product ordering information and to obtain the specific Automotive Reliability reports for these models.
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AD8541AKSZ-R2 AD8541AKSZ-REEL7 AD8541ARTZ-R2 AD8541ARTZ-REEL7 AD8541ARZ AD8542ARMZ AD8542ARMZ-REEL AD8542ARUZ AD8542ARZ AD8542ARZ-REEL7 AD8544ARUZ AD8544ARZ AD8541ARTZ- REEL AD8541ARZ-REEL AD8541ARZ-REEL7 AD8542ARUZ-REEL AD8542ARZ-REEL AD8544ARUZ-REEL AD8544ARZ-REEL AD8544ARZ-REEL7 AD8544WARZ-R7 AD8544WARZ-RL