AD ADA4528-1ARMZ-R7 Precision, ultralow noise, rrio, zero-drift op amp Datasheet

Precision, Ultralow Noise, RRIO,
Zero-Drift Op Amp
ADA4528-1/ADA4528-2
Data Sheet
PIN CONNECTION DIAGRAMS
Low offset voltage: 2.5 µV maximum
Low offset voltage drift: 0.015 μV/°C maximum
Low noise
5.6 nV/√Hz at f = 1 kHz, AV = +100
97 nV p-p at f = 0.1 Hz to 10 Hz, AV = +100
Open-loop gain: 130 dB minimum
CMRR: 135 dB minimum
PSRR: 130 dB minimum
Unity-gain crossover: 4 MHz
Gain bandwidth product: 3 MHz at AV = +100
−3 dB closed-loop bandwidth: 6.2 MHz
Single-supply operation: 2.2 V to 5.5 V
Dual-supply operation: ±1.1 V to ±2.75 V
Rail-to-rail input and output
Unity-gain stable
NIC 1
ADA4528-1
+IN 3
TOP VIEW
(Not to Scale)
V– 4
8
NIC
7
V+
6
OUT
5
NIC
NOTES
1. NIC = NO INTERNAL CONNECTION.
Figure 1. ADA4528-1 Pin Configuration, 8-Lead MSOP
NIC 1
8 NIC
–IN 2
ADA4528-1
+IN 3
TOP VIEW
(Not to Scale)
V– 4
7 V+
6 OUT
09437-102
5 NIC
NOTES
1. NIC = NO INTERNAL CONNECTION.
2. CONNECT THE EXPOSED PAD TO
V– OR LEAVE IT UNCONNECTED.
APPLICATIONS
Figure 2. ADA4528-1 Pin Configuration, 8-Lead LFCSP
Thermocouple/thermopile
Load cell and bridge transducers
Precision instrumentation
Electronic scales
Medical instrumentation
Handheld test equipment
For ADA4528-2 pin connections and for more information about
the pin connections for these products, see the Pin Configurations
and Function Descriptions section.
The ADA4528-1/ADA4528-2 are ultralow noise, zero-drift
operational amplifiers featuring rail-to-rail input and output
swing. With an offset voltage of 2.5 μV, offset voltage drift of
0.015 μV/°C, and typical noise of 97 nV p-p (0.1 Hz to 10 Hz,
AV = +100), the ADA4528-1/ADA4528-2 are well suited for
applications in which error sources cannot be tolerated.
The ADA4528-1/ADA4528-2 have a wide operating supply range
of 2.2 V to 5.5 V, high gain, and excellent CMRR and PSRR
specifications, which make it ideal for applications that require
precision amplification of low level signals, such as position and
pressure sensors, strain gages, and medical instrumentation.
The ADA4528-1/ADA4528-2 are specified over the extended
industrial temperature range (−40°C to +125°C). The ADA4528-1
and ADA4528-2 are available in 8-lead MSOP and 8-lead
LFCSP packages.
For more information about the ADA4528-1/ADA4528-2,
see the AN-1114 Application Note, Lowest Noise Zero-Drift
Amplifier Has 5.6 nV/√Hz Voltage Noise Density.
VSY = 5V
AV = 1
VCM = VSY/2
10
1
1
10
100
1k
10k
100k
1M
FREQUENCY (Hz)
10M
09437-063
VOLTAGE NOISE DENSITY (nV/√Hz)
100
GENERAL DESCRIPTION
Figure 3. Voltage Noise Density vs. Frequency
Table 1. Analog Devices, Inc., Zero-Drift Op Amp Portfolio 1
Low
Micropower Power
Type
(<20 µA)
(<1 mA)
Single ADA4528-1 ADA4051-1 AD8628
AD8538
Dual
ADA4528-2 ADA4051-2 AD8629
AD8539
Quad
AD8630
Ultralow
Noise
1
Rev. D
–IN 2
09437-001
FEATURES
16 V
Operating
Voltage
AD8638
30 V
Operating
Voltage
ADA4638-1
AD8639
See www.analog.com for the latest selection of zero-drift operational amplifiers.
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PARAMETRIC SELECTION TABLES
PRODUCT RECOMMENDATIONS & REFERENCE DESIGNS
AD8628, AD8629, AD8630: available in single, dual, and quad
channel counts offering lower supply current and input bias current in
a zero-drift precision Op Amp.
CN-0216: Precision Weigh Scale Design Using the AD7791 24-Bit
Sigma-Delta ADC with External ADA4528-1 Zero-Drift Amplifiers
AD8538 and AD8539: available in single and dual channel versions
offering lower supply current in a zero-drift precision Op Amp.
AD8551, AD8552, AD8554: available in single, dual, and quad
channel versions offering lower supply current in a zero-drift precision
Op Amp.
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AD8571 and AD8572: available in single and dual channel versions
offering lower supply current in a zero-drift precision Op Amp.
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DOCUMENTATION
AN-1114: Lowest Noise Zero-Drift Amplifier Has 5.6 nV/√Hz Voltage
Noise Density
AN-940: Low Noise Amplifier Selection Guide for Optimal Noise
Performance
CN-0216: Precision Weigh Scale Design Using the AD7791 24-Bit
Sigma-Delta ADC with External ADA4528-1 Zero-Drift Amplifiers
ADA4528: Lowest Noise, Zero-Drift Amplifier Enabling 24-bit
Resolution (Video)
Op Amp Applications Handbook
MS-2066: Low Noise Signal Conditioning for Sensor-Based Circuits
Visit the ADA4528-1/4528-2 Product Page for Practical Analog
Design Techniques and more documentation.
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ADA4528-1/ADA4528-2
Data Sheet
TABLE OF CONTENTS
Features .............................................................................................. 1
Pin Configurations and Function Descriptions ............................8
Applications ....................................................................................... 1
Typical Performance Characteristics ........................................... 10
General Description ......................................................................... 1
Applications Information .............................................................. 20
Pin Connection Diagrams ............................................................... 1
Input Protection ......................................................................... 20
Revision History ............................................................................... 2
Rail-to-Rail Input and Output .................................................. 20
Specifications..................................................................................... 3
Noise Considerations ................................................................. 20
Electrical Characteristics—2.5 V Operation ............................ 3
Comparator Operation .............................................................. 22
Electrical Characteristics—5 V Operation................................ 5
Printed Circuit Board Layout ................................................... 23
Absolute Maximum Ratings ............................................................ 7
Outline Dimensions ....................................................................... 24
Thermal Resistance ...................................................................... 7
Ordering Guide .......................................................................... 25
ESD Caution .................................................................................. 7
REVISION HISTORY
5/13—Rev. C to Rev. D
Added 8-Lead LFCSP Package (CP-8-11) ....................... Universal
Changes to Table 5 ............................................................................ 7
Added Figure 7, Renumbered Sequentially .................................. 8
Added Figure 62 and Figure 63..................................................... 19
Changes to Comparator Operation Section, Figure 68,
Figure 69, Figure 70, and Figure 71 .............................................. 21
Changes to Figure 72 ...................................................................... 22
Added Figure 76.............................................................................. 24
9/12—Rev. B to Rev. C
Changes to Features Section............................................................ 1
Added Comparator Operation Section ....................................... 21
Added Figure 65 to Figure 69; Renumbered Sequentially ........ 21
7/12—Rev. A to Rev. B
Added ADA4528-2 ............................................................. Universal
Changes to Features Section, Figure 1, Figure 2, and Table 1 .... 1
Added Pin Connection Diagrams Section and Figure 3;
Renumbered Sequentially................................................................ 1
Changes to Table 2 ............................................................................ 3
Changes to Table 3 ............................................................................ 5
Change to Endnote 1 of Table 4 and Thermal Resistance
Section ................................................................................................ 7
Added Pin Configurations and Function Descriptions Section,
Figure 4, Figure 5, and Table 6 ........................................................ 8
Added Figure 6 and Table 7 .............................................................9
Changes to Input Protection Section ........................................... 19
Changes to Source Resistance Section and
Caption of Figure 63....................................................................... 20
Changes to Residual Voltage Ripple Section and
Caption of Figure 64....................................................................... 21
Changes to Ordering Guide .......................................................... 22
9/11—Rev. 0 to Rev. A
Added 8-Lead LFCSP_WD Package ................................ Universal
Changes to General Description Section ......................................1
Added Figure 2; Renumbered Sequentially ...................................1
Changes to Offset Voltage, Offset Voltage Drift, Power Supply
Rejection Ratio, and Settling Time to 0.1% Parameters, Table 2 ...3
Changes to Thermal Resistance Section and Table 5 ...................5
Changes to Figure 41 and Figure 44 ............................................ 12
Changes to Figure 45 and Figure 48 ............................................ 13
Updated Outline Dimensions ....................................................... 18
Changes to Ordering Guide .......................................................... 18
1/11—Revision 0: Initial Version
Rev. D | Page 2 of 28
Data Sheet
ADA4528-1/ADA4528-2
SPECIFICATIONS
ELECTRICAL CHARACTERISTICS—2.5 V OPERATION
VSY = 2.5 V, VCM = VSY/2, TA = 25°C, unless otherwise specified.
Table 2.
Parameter
INPUT CHARACTERISTICS
Offset Voltage
Symbol
Test Conditions/Comments
VOS
Offset Voltage Drift
ΔVOS/ΔT
VCM = 0 V to 2.5 V
−40°C ≤ TA ≤ +125°C, MSOP package
−40°C ≤ TA ≤ +125°C, LFCSP package
−40°C ≤ TA ≤ +125°C, MSOP package
−40°C ≤ TA ≤ +125°C, LFCSP package
Input Bias Current
IB
Min
Typ
Max
Unit
0.3
2.5
4
4.3
0.015
0.018
400
600
800
1
2.5
μV
μV
μV
μV/°C
μV/°C
pA
pA
pA
nA
V
dB
dB
dB
dB
dB
dB
dB
dB
0.002
220
−40°C ≤ TA ≤ +125°C
Input Offset Current
IOS
440
−40°C ≤ TA ≤ +125°C
Input Voltage Range
Common-Mode Rejection Ratio
CMRR
Open-Loop Gain
AVO
ADA4528-1
ADA4528-2
Input Resistance
Differential Mode
Common Mode
Input Capacitance
Differential Mode
Common Mode
OUTPUT CHARACTERISTICS
Output Voltage High
Output Voltage Low
Short-Circuit Current
Closed-Loop Output Impedance
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current per Amplifier
DYNAMIC PERFORMANCE
Slew Rate
Settling Time to 0.1%
Unity-Gain Crossover
Phase Margin
Gain Bandwidth Product
−3 dB Closed-Loop Bandwidth
Overload Recovery Time
VCM = 0 V to 2.5 V
−40°C ≤ TA ≤ +125°C
RL = 10 kΩ, VO = 0.1 V to 2.4 V
−40°C ≤ TA ≤ +125°C
RL = 2 kΩ, VO = 0.1 V to 2.4 V
−40°C ≤ TA ≤ +125°C
RL = 2 kΩ, VO = 0.1 V to 2.4 V
−40°C ≤ TA ≤ +125°C
0
135
116
130
126
125
121
122
119
158
140
132
132
RINDM
RINCM
225
1
kΩ
GΩ
CINDM
CINCM
15
30
pF
pF
2.495
V
V
V
V
mV
mV
mV
mV
mA
Ω
VOH
VOL
ISC
ZOUT
PSRR
ISY
SR
tS
UGC
ΦM
GBP
f−3dB
RL = 10 kΩ to VCM
−40°C ≤ TA ≤ +125°C
RL = 2 kΩ to VCM
−40°C ≤ TA ≤ +125°C
RL = 10 kΩ to VCM
−40°C ≤ TA ≤ +125°C
RL = 2 kΩ to VCM
−40°C ≤ TA ≤ +125°C
2.49
2.485
2.46
2.44
5
20
RL = 10 kΩ, CL = 100 pF, AV = +1
VIN = 1.5 V step, RL = 10 kΩ, CL = 100 pF, AV = −1
VIN = 10 mV p-p, RL = 10 kΩ, CL = 100 pF, AV = +1
VIN = 10 mV p-p, RL = 10 kΩ, CL = 100 pF, AV = +1
VIN = 10 mV p-p, RL = 10 kΩ, CL = 100 pF, AV = +100
VIN = 10 mV p-p, RL = 10 kΩ, CL = 100 pF, AV = +1
RL = 10 kΩ, CL = 100 pF, AV = −10
Rev. D | Page 3 of 28
10
15
40
60
±30
0.1
f = 1 kHz, AV = +10
VSY = 2.2 V to 5.5 V
−40°C ≤ TA ≤ +125°C
IO = 0 mA
−40°C ≤ TA ≤ +125°C
2.48
130
127
150
1.4
0.45
7
4
57
3
6.2
50
1.7
2.1
dB
dB
mA
mA
V/μs
µs
MHz
Degrees
MHz
MHz
μs
ADA4528-1/ADA4528-2
Data Sheet
Parameter
NOISE PERFORMANCE
Voltage Noise
Voltage Noise Density
Symbol
Test Conditions/Comments
en p-p
en
Current Noise
Current Noise Density
in p-p
in
f = 0.1 Hz to 10 Hz, AV = +100
f = 1 kHz, AV = +100
f = 1 kHz, AV = +100, VCM = 2.0 V
f = 0.1 Hz to 10 Hz, AV = +100
f = 1 kHz, AV = +100
Rev. D | Page 4 of 28
Min
Typ
97
5.6
5.5
10
0.7
Max
Unit
nV p-p
nV/√Hz
nV/√Hz
pA p-p
pA/√Hz
Data Sheet
ADA4528-1/ADA4528-2
ELECTRICAL CHARACTERISTICS—5 V OPERATION
VSY = 5 V, VCM = VSY/2, TA = 25°C, unless otherwise specified.
Table 3.
Parameter
INPUT CHARACTERISTICS
Offset Voltage
Offset Voltage Drift
Input Bias Current
Symbol
Test Conditions/Comments
VOS
VCM = 0 V to 5 V
−40°C ≤ TA ≤ +125°C
−40°C ≤ TA ≤ +125°C
ΔVOS/ΔT
IB
Min
Typ
Max
Unit
0.3
2.5
4
0.015
μV
μV
μV/°C
200
300
250
350
pA
pA
pA
pA
400
500
500
600
5
pA
pA
pA
pA
V
dB
dB
dB
dB
dB
dB
0.002
90
ADA4528-1
−40°C ≤ TA ≤ +125°C
125
ADA4528-2
−40°C ≤ TA ≤ +125°C
Input Offset Current
IOS
180
ADA4528-1
−40°C ≤ TA ≤ +125°C
250
ADA4528-2
−40°C ≤ TA ≤ +125°C
Input Voltage Range
Common-Mode Rejection Ratio
CMRR
Open-Loop Gain
AVO
Input Resistance
Differential Mode
Common Mode
Input Capacitance
Differential Mode
Common Mode
OUTPUT CHARACTERISTICS
Output Voltage High
Output Voltage Low
Short-Circuit Current
Closed-Loop Output Impedance
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current per Amplifier
DYNAMIC PERFORMANCE
Slew Rate
Settling Time to 0.1%
Unity-Gain Crossover
Phase Margin
Gain Bandwidth Product
−3 dB Closed-Loop Bandwidth
Overload Recovery Time
VCM = 0 V to 5 V
−40°C ≤ TA ≤ +125°C
RL = 10 kΩ, VO = 0.1 V to 4.9 V
−40°C ≤ TA ≤ +125°C
RL = 2 kΩ, VO = 0.1 V to 4.9 V
−40°C ≤ TA ≤ +125°C
0
137
122
127
125
121
120
160
139
131
RINDM
RINCM
190
1
kΩ
GΩ
CINDM
CINCM
16.5
33
pF
pF
4.995
V
V
V
V
mV
mV
mV
mV
mA
Ω
VOH
VOL
ISC
ZOUT
PSRR
ISY
SR
tS
UGC
ΦM
GBP
f−3dB
RL = 10 kΩ to VCM
−40°C ≤ TA ≤ +125°C
RL = 2 kΩ to VCM
−40°C ≤ TA ≤ +125°C
RL = 10 kΩ to VCM
−40°C ≤ TA ≤ +125°C
RL = 2 kΩ to VCM
−40°C ≤ TA ≤ +125°C
4.99
4.98
4.96
4.94
5
20
RL = 10 kΩ, CL = 100 pF, AV = +1
VIN = 4 V step, RL = 10 kΩ, CL = 100 pF, AV = −1
VIN = 10 mV p-p, RL = 10 kΩ, CL = 100 pF, AV = +1
VIN = 10 mV p-p, RL = 10 kΩ, CL = 100 pF, AV = +1
VIN = 10 mV p-p, RL = 10 kΩ, CL = 100 pF, AV = +100
VIN = 10 mV p-p, RL = 10 kΩ, CL = 100 pF, AV = +1
RL = 10 kΩ, CL = 100 pF, AV = −10
Rev. D | Page 5 of 28
10
20
40
60
±40
0.1
f = 1 kHz, AV = +10
VSY = 2.2 V to 5.5 V
−40°C ≤ TA ≤ +125°C
IO = 0 mA
−40°C ≤ TA ≤ +125°C
4.98
130
127
150
1.5
0.5
10
4
57
3.4
6.5
50
1.8
2.2
dB
dB
mA
mA
V/μs
µs
MHz
Degrees
MHz
MHz
μs
ADA4528-1/ADA4528-2
Data Sheet
Parameter
NOISE PERFORMANCE
Voltage Noise
Voltage Noise Density
Symbol
Test Conditions/Comments
en p-p
en
Current Noise
Current Noise Density
in p-p
in
f = 0.1 Hz to 10 Hz, AV = +100
f = 1 kHz, AV = +100
f = 1 kHz, AV = +100, VCM = 4.5 V
f = 0.1 Hz to 10 Hz, AV = +100
f = 1 kHz, AV = +100
Rev. D | Page 6 of 28
Min
Typ
99
5.9
5.3
10
0.5
Max
Unit
nV p-p
nV/√Hz
nV/√Hz
pA p-p
pA/√Hz
Data Sheet
ADA4528-1/ADA4528-2
ABSOLUTE MAXIMUM RATINGS
THERMAL RESISTANCE
Table 4.
Parameter
Supply Voltage
Input Voltage
Input Current1
Differential Input Voltage
Output Short-Circuit Duration to GND
Storage Temperature Range
Operating Temperature Range
Junction Temperature Range
Lead Temperature (Soldering, 60 sec)
1
Rating
6V
±VSY ± 0.3 V
±10 mA
±VSY
Indefinite
−65°C to +150°C
−40°C to +125°C
−65°C to +150°C
300°C
θJA is specified for the worst-case conditions, that is, a device
soldered in a circuit board for surface-mount packages using a
4-layer JEDEC board. The exposed pad of the LFCSP package is
soldered to the board.
Table 5. Thermal Resistance
Package Type
8-Lead MSOP (RM-8)
8-Lead LFCSP (CP-8-12)
8-Lead LFCSP (CP-8-11)
The input pins have clamp diodes to the power supply pins. Limit the input
current to 10 mA or less whenever input signals exceed the power supply
rail by 0.3 V.
1
θJA
142
80
83.5
θJC is measured on the top surface of the package.
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. D | Page 7 of 28
θJC
45
601
48.51
Unit
°C/W
°C/W
°C/W
ADA4528-1/ADA4528-2
Data Sheet
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
NIC 1
ADA4528-1
+IN 3
TOP VIEW
(Not to Scale)
V– 4
NIC
7
V+
6
OUT
5
NIC
NOTES
1. NIC = NO INTERNAL CONNECTION.
8 NIC
–IN 2
ADA4528-1
+IN 3
TOP VIEW
(Not to Scale)
V– 4
5 NIC
Figure 5. ADA4528-1 Pin Configuration, 8-Lead LFCSP
Table 6. ADA4528-1 Pin Function Descriptions
Mnemonic
NIC
−IN
+IN
V−
OUT
V+
EPAD
6 OUT
NOTES
1. NIC = NO INTERNAL CONNECTION.
2. CONNECT THE EXPOSED PAD TO
V– OR LEAVE IT UNCONNECTED.
Figure 4. ADA4528-1 Pin Configuration, 8-Lead MSOP
Pin No.
1, 5, 8
2
3
4
6
7
7 V+
09437-102
–IN 2
8
09437-001
NIC 1
Description
No Internal Connection.
Inverting Input.
Noninverting Input.
Negative Supply Voltage.
Output.
Positive Supply Voltage.
Exposed Pad (LFCSP Only). Connect the exposed pad to V− or leave it unconnected.
Rev. D | Page 8 of 28
ADA4528-1/ADA4528-2
–IN A 2
ADA4528-2
+IN A 3
TOP VIEW
(Not to Scale)
V–
4
8
V+
7
OUT B
6
–IN B
5
+IN B
OUT A 1
09437-103
OUT A 1
8 V+
–IN A 2
ADA4528-2
7 OUT B
+IN A 3
TOP VIEW
(Not to Scale)
6 –IN B
V– 4
5 +IN B
NOTES
1. CONNECT THE EXPOSED PAD TO
V– OR LEAVE IT UNCONNECTED.
Figure 6. ADA4528-2 Pin Configuration, 8-Lead MSOP
09437-107
Data Sheet
Figure 7. ADA4528-2 Pin Configuration, 8-Lead LFCSP
Table 7. ADA4528-2 Pin Function Descriptions
Pin No.
1
2
3
4
5
6
7
8
Mnemonic
OUT A
−IN A
+IN A
V−
+IN B
−IN B
OUT B
V+
EPAD
Description
Output, Channel A.
Inverting Input, Channel A.
Noninverting Input, Channel A.
Negative Supply Voltage.
Noninverting Input, Channel B.
Inverting Input, Channel B.
Output, Channel B.
Positive Supply Voltage.
Connect the exposed pad to V- or leave it unconnected.
Rev. D | Page 9 of 28
ADA4528-1/ADA4528-2
Data Sheet
TYPICAL PERFORMANCE CHARACTERISTICS
TA = 25°C, unless otherwise noted.
100
100
VSY = 2.5V
VCM = VSY/2
90
80
70
60
50
40
30
70
60
50
40
30
20
20
10
10
–0.8
–0.6
–0.4
–0.2
0
0.2
VOS (µV)
0.4
0.6
0.8
1.0
0
–1.0
09437-002
0
–1.0
Figure 8. Input Offset Voltage Distribution
–0.6
–0.2
0
0.2
VOS (µV)
0.4
0.6
0.8
1.0
60
VSY = 2.5V
VCM = VSY/2
VSY = 5V
VCM = VSY/2
50
NUMBER OF AMPLIFIERS
50
40
30
20
10
40
30
20
0
3
6
9
12
09437-006
09437-003
10
0
0
15
0
3
TCVOS (nV/°C)
9
6
12
15
TCVOS (nV/°C)
Figure 9. Input Offset Voltage Drift Distribution
Figure 12. Input Offset Voltage Drift Distribution
1.0
1.0
VSY = 5V
VSY = 2.5V
0.8
0.6
0.6
0.4
0.4
0.2
0.2
0
–0.2
0
–0.2
–0.4
–0.4
–0.6
–0.6
–0.8
–0.8
–1.0
0
0.5
1.5
1.0
2.0
2.5
VCM (V)
Figure 10. Input Offset Voltage vs. Common-Mode Voltage
–1.0
0
1
3
2
4
VCM (V)
Figure 13. Input Offset Voltage vs. Common-Mode Voltage
Rev. D | Page 10 of 28
5
09437-007
VOS (µV)
0.8
09437-004
VOS (µV)
–0.4
Figure 11. Input Offset Voltage Distribution
60
NUMBER OF AMPLIFIERS
–0.8
09437-005
NUMBER OF AMPLIFIERS
80
NUMBER OF AMPLIFIERS
VSY = 5V
VCM = VSY/2
90
Data Sheet
ADA4528-1/ADA4528-2
400
400
VSY = 2.5V
VCM = VSY/2
300
IB+
200
200
100
IB+
100
IB (pA)
IB (pA)
VSY = 5V
VCM = VSY/2
300
0
–100
0
IB–
–100
–200
–300
–300
–25
0
25
50
75
100
125
TEMPERATURE (°C)
–400
–50
09437-008
–400
–50
–25
0
25
50
75
100
125
TEMPERATURE (°C)
Figure 14. Input Bias Current vs. Temperature
09437-110
IB–
–200
Figure 17. Input Bias Current vs. Temperature
600
600
400
+85°C
400
+85°C
–40°C
200
–40°C
200
IB (pA)
IB (pA)
+25°C
+125°C
0
0
+25°C
–200
+125°C
–200
–400
–400
–600
0.5
1.0
1.5
2.0
2.5
VCM (V)
0
4
5
10
OUTPUT VOLTAGE (VOL) TO SUPPLY RAIL (V)
VSY = 2.5V
1
100m
–40°C
+25°C
+85°C
+125°C
1m
0.01
0.1
1
LOAD CURRENT (mA)
10
100
09437-014
OUTPUT VOLTAGE (VOL) TO SUPPLY RAIL (V)
3
Figure 18. Input Bias Current vs. Common-Mode Voltage
10
0.1m
0.001
2
VCM (V)
Figure 15. Input Bias Current vs. Common-Mode Voltage
10m
1
VS = 5V
1
100m
10m
–40°C
+25°C
+85°C
+125°C
1m
0.1m
0.001
0.01
0.1
1
LOAD CURRENT (mA)
10
100
Figure 19. Output Voltage (VOL) to Supply Rail vs. Load Current
Figure 16. Output Voltage (VOL) to Supply Rail vs. Load Current
Rev. D | Page 11 of 28
09437-017
0
–800
09437-009
–600
09437-012
VSY = 5V
VSY = 2.5V
ADA4528-1/ADA4528-2
Data Sheet
10
1
100m
–40°C
+25°C
+85°C
+125°C
1m
0.01
0.1
1
LOAD CURRENT (mA)
10
100m
100
Figure 20. Output Voltage (VOH) to Supply Rail vs. Load Current
OUTPUT VOLTAGE (VOL) TO SUPPLY RAIL (mV)
RL = 2kΩ
15
10
RL = 10kΩ
5
–25
0
75
50
25
TEMPERATURE (°C)
100
125
OUTPUT VOLTAGE (VOH) TO SUPPLY RAIL (mV)
25
RL = 2kΩ
20
15
10
RL = 10kΩ
5
0
–50
–25
0
75
50
25
TEMPERATURE (°C)
100
125
0.1m
0.001
0.01
1
0.1
LOAD CURRENT (mA)
10
100
45
VSY = 5V
40
RL = 2kΩ
35
30
25
20
15
RL = 10kΩ
10
5
–25
0
75
50
25
TEMPERATURE (°C)
100
125
Figure 24. Output Voltage (VOL) to Supply Rail vs. Temperature
25
VSY = 5V
Figure 22. Output Voltage (VOH) to Supply Rail vs. Temperature
RL = 2kΩ
20
15
10
RL = 10kΩ
5
0
–50
09437-015
OUTPUT VOLTAGE (VOH) TO SUPPLY RAIL (mV)
Figure 21. Output Voltage (VOL) to Supply Rail vs. Temperature
VSY = 2.5V
1m
0
–50
09437-016
OUTPUT VOLTAGE (VOL) TO SUPPLY RAIL (mV)
VSY = 2.5V
0
–50
10m
Figure 23. Output Voltage (VOH) to Supply Rail vs. Load Current
25
20
–40°C
+25°C
+85°C
+125°C
09437-019
0.1m
0.001
1
–25
0
75
50
25
TEMPERATURE (°C)
100
125
Figure 25. Output Voltage (VOH) to Supply Rail vs. Temperature
Rev. D | Page 12 of 28
09437-117
10m
VSY = 5V
09437-013
OUTPUT VOLTAGE (VOH) TO SUPPLY RAIL (V)
VSY = 2.5V
09437-010
OUTPUT VOLTAGE (VOH) TO SUPPLY RAIL (V)
10
Data Sheet
ADA4528-1/ADA4528-2
2.00
2.0
+125°C
1.8
+85°C
1.50
ISY PER AMPLIFIER (mA)
ISY PER AMPLIFIER (mA)
1.75
+25°C
1.25
–40°C
1.00
0.75
0.50
VSY = 5.0V
1.6
VSY = 2.5V
1.4
1.2
2.5 3.0
VSY (V)
4.0
3.5
4.5
5.5
5.0
1.0
–50
–25
25
0
Figure 26. Supply Current vs. Supply Voltage
75
100
125
Figure 29. Supply Current vs. Temperature
135
120
90
90
90
90
60
45
60
45
120
135
PHASE
0
VSY = 2.5V
RL = 10kΩ
CL = 100pF
–30
1k
GAIN
30
10k
–90
10M
1M
100k
0
VSY = 5V
RL = 10kΩ
CL = 100pF
0
–45
09437-022
0
PHASE (Degrees)
GAIN
30
OPEN-LOOP GAIN (dB)
PHASE
FREQUENCY (Hz)
–30
1k
–45
10k
Figure 30. Open-Loop Gain and Phase vs. Frequency
60
60
VSY = 2.5V
VSY = 5V
50
50
AV = 100
CLOSED-LOOP GAIN (dB)
AV = 100
40
30
AV = 10
20
10
AV = 1
0
40
30
AV = 10
20
10
AV = 1
0
–10
100
1k
10k
100k
1M
FREQUENCY (Hz)
10M
09437-026
–10
–20
10
–90
10M
1M
100k
FREQUENCY (Hz)
Figure 27. Open-Loop Gain and Phase vs. Frequency
CLOSED-LOOP GAIN (dB)
OPEN-LOOP GAIN (dB)
50
TEMPERATURE (°C)
PHASE (Degrees)
2.0
1.5
1.0
09437-025
0.5
Figure 28. Closed-Loop Gain vs. Frequency
–20
10
100
1k
10k
100k
1M
FREQUENCY (Hz)
Figure 31. Closed-Loop Gain vs. Frequency
Rev. D | Page 13 of 28
10M
09437-029
0
09437-021
0
09437-024
0.25
ADA4528-1/ADA4528-2
Data Sheet
140
160
VSY = 2.5V
140
VSY = 5V
VCM = VSY/2
120
120
CMRR (dB)
80
60
VCM = VSY/2
VCM = 1.1V
10k
100k
1M
10M
FREQUENCY (Hz)
0
100
09437-126
1k
10k
1k
Figure 32. CMRR vs. Frequency
120
VSY = 5V
100
100
80
80
PSRR (dB)
60
PSRR+
40
60
PSRR+
40
PSRR–
PSRR–
20
20
0
0
100k
1M
10M
FREQUENCY (Hz)
–20
100
09437-032
10k
1k
10k
100k
1M
10M
FREQUENCY (Hz)
Figure 33. PSRR vs. Frequency
Figure 36. PSRR vs. Frequency
1k
1k
VSY = 2.5V
VSY = 5V
100
100
10
10
ZOUT (Ω)
AV = 100
AV = 10
1
AV = 1
AV = 100
AV = 1
0.1
0.01
0.01
1k
10k
100k
1M
FREQUENCY (Hz)
10M
Figure 34. Closed-Loop Output Impedance vs. Frequency
AV = 10
1
0.1
09437-027
ZOUT (Ω)
1k
09437-035
PSRR (dB)
VSY = 2.5V
0.001
100
10M
Figure 35. CMRR vs. Frequency
120
–20
100
1M
100k
FREQUENCY (Hz)
09437-031
20
0
100
60
40
40
20
80
0.001
100
1k
10k
100k
1M
FREQUENCY (Hz)
Figure 37. Closed-Loop Output Impedance vs. Frequency
Rev. D | Page 14 of 28
10M
09437-030
CMRR (dB)
100
100
ADA4528-1/ADA4528-2
VOLTAGE (1V/DIV)
TIME (20µs/DIV)
TIME (20µs/DIV)
Figure 41. Large Signal Transient Response
VOLTAGE (50mV/DIV)
VOLTAGE (50mV/DIV)
Figure 38. Large Signal Transient Response
VSY = ±2.5V
VIN = 100mV p-p
AV = 1
RL = 10kΩ
CL = 100pF
09437-038
VSY = ±1.25V
VIN = 100mV p-p
AV = 1
RL = 10kΩ
CL = 100pF
TIME (1µs/DIV)
TIME (1µs/DIV)
Figure 39. Small Signal Transient Response
Figure 42. Small Signal Transient Response
16
16
VSY = 2.5V
VIN = 100mV p-p
AV = 1
RL = 10kΩ
14
VSY = 5V
VIN = 100mV p-p
AV = 1
RL = 10kΩ
14
12
OS+
10
8
OS–
6
10
8
6
4
4
2
2
1
10
100
1000
LOAD CAPACITANCE (pF)
OS–
0
09437-033
0
OS+
1
10
100
1000
LOAD CAPACITANCE (pF)
Figure 40. Small Signal Overshoot vs. Load Capacitance
Figure 43. Small Signal Overshoot vs. Load Capacitance
Rev. D | Page 15 of 28
09437-036
OVERSHOOT (%)
12
OVERSHOOT (%)
09437-037
VSY = ±2.5V
VIN = 4V p-p
AV = 1
RL = 10kΩ
CL = 100pF
09437-034
VSY = ±1.25V
VIN = 2V p-p
AV = 1
RL = 10kΩ
CL = 100pF
09437-041
VOLTAGE (0.5V/DIV)
Data Sheet
INPUT
0
VSY = ±1.25V
AV = –10
VIN = 187.5mV
RL = 10kΩ
CL = 100pF
0
OUTPUT
1
0
–1
TIME (10µs/DIV)
–0.5
3
1
OUTPUT
0
–1
TIME (10µs/DIV)
VSY = ±1.25V
AV = –10
VIN = 187.5mV
RL = 10kΩ
CL = 100pF
INPUT
0
–0.5
1
OUTPUT
0
–1
–2
TIME (10µs/DIV)
–1
VSY = ±2.5V
AV = –10
VIN = 375mV
RL = 10kΩ
CL = 100pF
09437-039
0
OUTPUT VOLTAGE (V)
1
OUTPUT
–2
OUTPUT VOLTAGE (V)
INPUT
0
0.5
09437-042
INPUT VOLTAGE (V)
Figure 47. Positive Overload Recovery
0.5
–3
TIME (10µs/DIV)
Figure 48. Negative Overload Recovery
Figure 45. Negative Overload Recovery
INPUT
INPUT
VOLTAGE (2V/DIV)
VSY = 2.5V
RL = 10kΩ
CL = 100pF
DUT AV = –1
+7.5mV
ERROR BAND
POST GAIN = 5
0
–7.5mV
+20mV
OUTPUT
0
ERROR BAND
POST GAIN = 5
–20mV
09437-047
OUTPUT
VSY = 5V
RL = 10kΩ
CL = 100pF
DUT AV = –1
09437-044
VOLTAGE (1V/DIV)
INPUT VOLTAGE (V)
VSY = ±2.5V
AV = –10
VIN = 375mV
RL = 10kΩ
CL = 100pF
2
Figure 44. Positive Overload Recovery
–0.5
INPUT
2
OUTPUT VOLTAGE (V)
–0.5
0.5
OUTPUT VOLTAGE (V)
0.5
09437-043
INPUT VOLTAGE (V)
Data Sheet
09437-040
INPUT VOLTAGE (V)
ADA4528-1/ADA4528-2
TIME (10µs/DIV)
TIME (10µs/DIV)
Figure 46. Positive Settling Time to 0.1%
Figure 49. Positive Settling Time to 0.1%
Rev. D | Page 16 of 28
Data Sheet
ADA4528-1/ADA4528-2
VSY = 2.5V
RL = 10kΩ
CL = 100pF
DUT AV = –1
+7.5mV
OUTPUT
0
ERROR BAND
POST GAIN = 5
INPUT
VOLTAGE (2V/DIV)
VOLTAGE (1V/DIV)
INPUT
VSY = 5V
RL = 10kΩ
CL = 100pF
DUT AV = –1
+20mV
ERROR BAND
POST GAIN = 5
OUTPUT
0
–7.5mV
TIME (10µs/DIV)
TIME (10µs/DIV)
Figure 50. Negative Settling Time to 0.1%
Figure 53. Negative Settling Time to 0.1%
100
10
1k
100
10
1
10k
FREQUENCY (Hz)
VSY = 5V
AV = 100
VCM = VSY/2
10
1
1
1k
10k
Figure 54. Voltage Noise Density vs. Frequency
10
10
1
1
10
100
1k
10k
FREQUENCY (Hz)
100k
Figure 52. Current Noise Density vs. Frequency
VSY = 5V
AV = 100
VCM = VSY/2
1
0.1
1
10
100
1k
10k
FREQUENCY (Hz)
Figure 55. Current Noise Density vs. Frequency
Rev. D | Page 17 of 28
100k
09437-153
CURRENT NOISE DENSITY (pA/√Hz)
VSY = 2.5V
AV = 100
VCM = VSY/2
09437-150
CURRENT NOISE DENSITY (pA/√Hz)
100
FREQUENCY (Hz)
Figure 51. Voltage Noise Density vs. Frequency
0.1
10
09437-049
VOLTAGE NOISE DENSITY (nV/√Hz)
VSY = 2.5V
AV = 100
VCM = VSY/2
09437-046
VOLTAGE NOISE DENSITY (nV/√Hz)
100
1
09437-048
09437-045
–20mV
ADA4528-1/ADA4528-2
Data Sheet
VSY = 5V
AV = 100
VCM = VSY/2
TIME (1s/DIV)
TIME (1s/DIV)
Figure 59. 0.1 Hz to 10 Hz Noise
10
1
1
0.1
0.001
0.001
0.1
VSY = 5V
AV = 1
f = 1kHz
RL = 10kΩ
0.01
VSY = 2.5V
AV = 1
f = 1kHz
RL = 10kΩ
0.01
0.1
1
10
AMPLITUDE (V p-p)
0.001
0.001
0.01
0.1
1
10
AMPLITUDE (V p-p)
Figure 57. THD + N vs. Amplitude
09437-155
THD + N (%)
10
09437-152
Figure 60. THD + N vs. Amplitude
1
1
VSY = 2.5V
AV = 1
RL = 10kΩ
80kHz LOW-PASS FILTER
VIN = 2V p-p
VSY = 5V
AV = 1
RL = 10kΩ
80kHz LOW-PASS FILTER
VIN = 2V p-p
0.1
THD + N (%)
THD + N (%)
0.1
0.01
100
1k
10k
FREQUENCY (Hz)
100k
09437-056
0.001
10
0.01
Figure 58. THD + N vs. Frequency
0.001
10
100
1k
10k
FREQUENCY (Hz)
Figure 61. THD + N vs. Frequency
Rev. D | Page 18 of 28
100k
09437-057
THD + N (%)
Figure 56. 0.1 Hz to 10 Hz Noise
0.01
09437-053
09437-050
INPUT VOLTAGE (20nV/DIV)
INPUT VOLTAGE (20nV/DIV)
VSY = 2.5V
AV = 100
VCM = VSY/2
Data Sheet
ADA4528-1/ADA4528-2
0
0
VSY = 2.5V
RL = 2kΩ
AV = –100
CHANNEL SEPERATION (dB)
–40
VIN = 0.5V p-p
VIN = 1V p-p
VIN = 1.2V p-p
–80
–100
–120
–140
100
–40
–60
VIN = 1V p-p
VIN = 2V p-p
VIN = 2.4V p-p
–80
–100
–120
1k
10k
FREQUENCY (Hz)
100k
Figure 62. Channel Separation vs. Frequency
–140
100
1k
10k
FREQUENCY (Hz)
Figure 63.Channel Separation vs. Frequency
Rev. D | Page 19 of 28
100k
09437-263
–60
VSY = 5V
RL = 2kΩ
AV = –100
–20
09437-262
CHANNEL SEPERATION (dB)
–20
ADA4528-1/ADA4528-2
Data Sheet
APPLICATIONS INFORMATION
Offset voltage errors due to common-mode voltage swings
and power supply variations are also corrected by the chopping
technique, resulting in a typical CMRR figure of 158 dB and a
PSRR figure of 150 dB at 2.5 V supply voltage. The ADA4528-1/
ADA4528-2 have low broadband noise of 5.6 nV/√Hz (at f =
1 kHz, AV = +100, and VSY = 2.5 V) with no 1/f noise component.
These features are ideal for amplification of low level signals in
dc or subhertz high precision applications.
RAIL-TO-RAIL INPUT AND OUTPUT
The ADA4528-1/ADA4528-2 feature rail-to-rail input and
output with a supply voltage from 2.2 V to 5.5 V. Figure 64
shows the input and output waveforms of the ADA45281/ADA4528-2 configured as a unity-gain buffer with a supply
voltage of ±2.5 V and a resistive load of 10 kΩ. With an input
voltage of ±2.5 V, the ADA4528-1/ADA4528-2 allow the output
to swing very close to both rails. Additionally, the parts do not
exhibit phase reversal.
3
1
VOLTAGE (V)
For more information about the chopper architecture of the
ADA4528-1/ADA4528-2, see the AN-1114 Application Note,
Lowest Noise Zero-Drift Amplifier Has 5.6 nV/√Hz Voltage
Noise Density.
0
–1
INPUT PROTECTION
The ADA4528-1/ADA4528-2 have internal ESD protection
diodes that are connected between the inputs and each supply
rail. These diodes protect the input transistors in the event of
electrostatic discharge and are reverse biased during normal
operation. This protection scheme allows voltages as high as
approximately 300 mV beyond the rails to be applied at the input
of either terminal without causing permanent damage (see
Table 4 in the Absolute Maximum Ratings section).
When either input exceeds one of the supply rails by more than
300 mV, the ESD diodes become forward biased and large amounts
of current begin to flow through them. Without current limiting,
this excessive fault current causes permanent damage to the device.
If the inputs will be subjected to overvoltage conditions, insert a
resistor in series with each input to limit the input current to 10 mA
maximum. However, consider the resistor thermal noise effect
on the entire circuit.
For example, at a 5 V supply voltage, the broadband voltage noise
of the ADA4528-1/ADA4528-2 is approximately 6 nV/√Hz (at
unity gain). A 1 kΩ resistor has thermal noise of 4 nV/√Hz. Adding
a 1 kΩ resistor at the noninverting input pin increases the total
noise by 30% root sum square (rss).
VIN
VOUT
2
–2
VSY = ±2.5V
AV = 1
RL = 10kΩ
–3
TIME (200µs/DIV)
09437-059
The ADA4528-1/ADA4528-2 are precision, ultralow noise,
zero-drift operational amplifiers that feature a patented chopping technique. This chopping technique offers ultralow input
offset voltage of 0.3 µV typical and input offset voltage drift of
0.002 µV/°C typical.
Figure 64. Rail-to-Rail Input and Output
NOISE CONSIDERATIONS
For more information about the noise characteristics of the
ADA4528-1/ADA4528-2, see the AN-1114 Application Note,
Lowest Noise Zero-Drift Amplifier Has 5.6 nV/√Hz Voltage Noise
Density.
1/f Noise
1/f noise, also known as pink noise or flicker noise, is inherent
in semiconductor devices and increases as frequency decreases.
At low frequency, 1/f noise is a major noise contributor and
causes a significant output voltage offset when amplified by the
noise gain of the circuit. However, the ADA4528-1/ADA4528-2
eliminate the 1/f noise internally, thus making these parts an
excellent choice for dc or subhertz high precision applications.
The 0.1 Hz to 10 Hz amplifier voltage noise is only 97 nV p-p
(AV = +100) at a supply voltage of 2.5 V.
The low frequency 1/f noise, which appears as a slow varying
offset to the ADA4528-1/ADA4528-2, is greatly reduced by
the chopping technique. This reduction in 1/f noise allows the
ADA4528-1/ADA4528-2 to have much lower noise at dc and
low frequency compared to standard low noise amplifiers that
are susceptible to 1/f noise. Figure 51 and Figure 54 show the
voltage noise density of the amplifier with no 1/f noise.
Rev. D | Page 20 of 28
Data Sheet
ADA4528-1/ADA4528-2
Source Resistance
Voltage Noise Density with Different Gain Configurations
With 5.6 nV/√Hz of broadband noise at 1 kHz (VSY = 2.5 V
and AV = +100), the ADA4528-1/ADA4528-2 are among the
lowest noise zero-drift amplifiers currently available in the
industry. Therefore, it is important to carefully select the input
source resistance to maintain a total low noise.
Figure 65 shows the voltage noise density vs. closed-loop gain of a
zero-drift amplifier from a leading competitor. The voltage noise
density of the amplifier increases from 11 nV/√Hz to 21 nV/√Hz
as the closed-loop gain decreases from 1000 to 1.
24
These uncorrelated noise sources can be summed up in a root
sum squared (rss) manner using the following equation:
en total = [en2 + 4 kTRS + (in × RS)2]1/2
where:
en is the input voltage noise of the amplifier (V/√Hz).
k is the Boltzmann’s constant (1.38 × 10−23 J/K).
T is the temperature in Kelvin (K).
RS is the total input source resistance (Ω).
in is the input current noise of the amplifier (A/√Hz).
VSY = 5V
f = 100Hz
COMPETITOR A
20
16
12
8
4
09437-061
VOLTAGE NOISE DENSITY (nV/√Hz)
The total input referred broadband noise (en total) from any
amplifier is primarily a function of three types of noise: input
voltage noise, input current noise, and thermal (Johnson) noise
from the external resistors.
0
1
10
100
1000
CLOSED-LOOP GAIN (V/V)
Figure 65. Competitor A: Voltage Noise Density vs. Closed-Loop Gain
Figure 66 shows the voltage noise density vs. frequency of the
ADA4528-1/ADA4528-2 for three different gain configurations.
The ADA4528-1/ADA4528-2 offer a constant input voltage
noise density of 6 nV/√Hz to 7 nV/√Hz, regardless of the gain
configuration.
where BW is the bandwidth in hertz.
This analysis is valid for broadband noise calculation. If the
bandwidth of concern includes the chopping frequency, more
complicated calculations must be made to include the effect of
the noise energy spectrum at the chopping frequency (see the
Residual Voltage Ripple section).
With a low source resistance of RS < 1 kΩ, the voltage noise
of the amplifier dominates. As source resistance increases, the
thermal noise of RS dominates. As the source resistance increases
further, where RS > 100 kΩ, the current noise becomes the main
contributor to the total input noise. A good selection table for low
noise op amps can be found in the AN-940 Application Note, Low
Noise Amplifier Selection Guide for Optimal Noise Performance.
100
VSY = 5V
VCM = VSY/2
10
AV = 1
AV = 10
AV = 100
1
1
10
100
1k
10k
FREQUENCY (Hz)
Figure 66. Voltage Noise Density vs. Frequency with Different Gain
Configurations
Rev. D | Page 21 of 28
09437-062
en,rms = en total × √BW
VOLTAGE NOISE DENSITY (nV/√Hz)
The total equivalent rms noise over a specific bandwidth is
expressed as
ADA4528-1/ADA4528-2
Data Sheet
3.5
Residual Voltage Ripple
2.5
2.0
1.5
1.0
0
0
0.5
1.0
1.5
2.0
2.5
3.0
VSY (V)
3.5
4.0
4.5
5.0
09437-066
0.5
VSY = 5V
AV = 1
VCM = VSY/2
Figure 69. Supply Current vs. Supply Voltage (Voltage Follower)
10
Figure 70 and Figure 71 show the ADA4528-2 configured as
comparators, with 1kΩ resistors in series with the input pins.
Figure 72 shows the supply currents for both configurations.
Supply currents increase slightly to 3.2 mA per dual amplifier at
5 V of supplies.
+VSY
10
100
1k
10k
100k
1M
FREQUENCY (Hz)
10M
A1
1kΩ
Figure 67. Voltage Noise Density vs. Frequency
To further suppress the noise at the chopping frequency, it is
recommended that a post filter be placed at the output of the
amplifier. For more information about residual voltage ripple,
see the AN-1114 Application Note, Lowest Noise Zero-Drift
Amplifier Has 5.6 nV/√Hz Voltage Noise Density.
ADA4528-2
VOUT
1/2
1kΩ
Figure 68 shows the ADA4528-2 configured as a voltage
follower with an input voltage that is always kept at midpoint
of the power supplies. The same configuration is applied to the
unused channel. A1 and A2 indicate the placement of ammeters
to measure supply current. As shown in Figure 69, as expected,
in normal operating condition, ISY+ = ISY− = 3 mA for the dual
ADA4528-2 at 5 V of supplies.
ISY–
A2
COMPARATOR OPERATION
–VSY
Figure 70. Comparator A
+VSY
+VSY
A1
ISY+
A1
ISY+
1kΩ
ISY+
ADA4528-2
1/2
1kΩ
ADA4528-2
1/2
1kΩ
A2
ISY–
VOUT
–VSY
A2
ISY–
–VSY
Figure 71. Comparator B
09437-065
1kΩ
VOUT
Figure 68. Voltage Follower
Rev. D | Page 22 of 26
09437-068
1
09437-067
1
09437-063
VOLTAGE NOISE DENSITY (nV/√Hz)
100
3.0
ISY PER DUAL AMPLIFIER (mA)
Although autocorrection feedback (ACFB) suppresses the chopping related voltage ripple, higher noise spectrum exists at the
chopping frequency and its harmonics due to the remaining ripple.
Figure 67 shows the voltage noise density of the ADA4528-1/
ADA4528-2 configured in unity gain. A noise energy spectrum
of 50 nV/√Hz can be seen at the chopping frequency of 200 kHz.
This noise energy spectrum is significant when the op amp has a
closed-loop frequency that is higher than the chopping frequency.
Data Sheet
ADA4528-1/ADA4528-2
junction. The most common metallic junctions on a circuit
board are solder-to-board trace and solder-to-component lead.
3.5
Figure 73 shows a cross section of a surface-mount component
soldered to a PCB. A variation in temperature across the board
(where TA1 ≠ TA2) causes a mismatch in the Seebeck voltages at
the solder joints, thereby resulting in thermal voltage errors
that degrade the ultralow offset voltage performance of the
ADA4528-1/ADA4528-2.
2.5
2.0
1.5
1.0
COMPONENT
LEAD
0.5
VSC1 +
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
VSY (V)
SURFACE-MOUNT
COMPONENT
+
VTS1 +
09437-069
0
VSC2
SOLDER
+ VTS2
PC BOARD
Figure 72. Supply Current vs. Supply Voltage (Comparator A and
Comparator B)
TA1
COPPER
TRACE
For more details on op amps as comparators, refer to the
AN-849 Application Note, Using Op Amps as Comparators.
TA2
IF TA1 ≠ TA2, THEN
VTS1 + VSC1 ≠ VTS2 + VSC2
09437-154
ISY PER DUAL AMPLIFIER (mA)
3.0
Figure 73. Mismatch in Seebeck Voltages Causes
Seebeck Voltage Error
PRINTED CIRCUIT BOARD LAYOUT
The ADA4528-1/ADA4528-2 are high precision devices with
ultralow offset voltage and noise. Therefore, care must be taken
in the design of the printed circuit board (PCB) layout to achieve
the optimum performance of the ADA4528-1/ADA4528-2 at
board level.
To avoid leakage currents, keep the surface of the board clean
and free of moisture. Coating the board surface creates a barrier
to moisture accumulation and reduces parasitic resistance on
the board.
To minimize power supply disturbances caused by output current
variation, properly bypass the power supplies and keep the supply
traces short. Connect bypass capacitors as close as possible to the
device supply pins.
Stray capacitances are a concern at the outputs and the inputs of
the amplifier. It is recommended that signal traces be kept at a
distance of at least 5 mm from supply lines to minimize coupling.
To minimize these thermocouple effects, orient resistors so that
heat sources warm both ends equally. Where possible, the input
signal paths should contain matching numbers and types of components to match the number and type of thermocouple junctions.
For example, dummy components, such as zero value resistors, can
be used to match the thermoelectric error source (real resistors
in the opposite input path). Place matching components in close
proximity and orient them in the same manner to ensure equal
Seebeck voltages, thus canceling thermal errors. Additionally, use
leads of equal length to keep thermal conduction in equilibrium.
Keep heat sources on the PCB as far away from the amplifier
input circuitry as practical.
It is highly recommended that a ground plane be used. A ground
plane helps to distribute heat throughout the board, maintains a
constant temperature across the board, and reduces EMI noise
pickup.
A potential source of offset error is the Seebeck voltage on the
circuit board. The Seebeck voltage occurs at the junction of two
dissimilar metals and is a function of the temperature of the
Rev. D | Page 23 of 28
ADA4528-1/ADA4528-2
Data Sheet
OUTLINE DIMENSIONS
3.20
3.00
2.80
8
3.20
3.00
2.80
1
5.15
4.90
4.65
5
4
PIN 1
IDENTIFIER
0.65 BSC
0.95
0.85
0.75
15° MAX
1.10 MAX
0.40
0.25
0.80
0.55
0.40
0.23
0.09
6°
0°
10-07-2009-B
0.15
0.05
COPLANARITY
0.10
COMPLIANT TO JEDEC STANDARDS MO-187-AA
Figure 74. 8-Lead Mini Small Outline Package [MSOP]
(RM-8)
Dimensions shown in millimeters
3.10
3.00 SQ
2.90
0.50 BSC
8
5
0.50
0.40
0.30
0.80
0.75
0.70
0.30
0.25
0.20
1
4
BOTTOM VIEW
TOP VIEW
SEATING
PLANE
1.70
1.60 SQ
1.50
EXPOSED
PAD
0.05 MAX
0.02 NOM
COPLANARITY
0.08
0.203 REF
PIN 1
INDICATOR
(R 0.15)
FOR PROPER CONNECTION OF
THE EXPOSED PAD, REFER TO
THE PIN CONFIGURATION AND
FUNCTION DESCRIPTIONS
SECTION OF THIS DATA SHEET.
COMPLIANT TO JEDEC STANDARDS MO-229-WEED
Figure 75. 8-Lead Lead Frame Chip Scale Package [LFCSP_WD]
3 mm × 3 mm Body, Very Very Thin, Dual Lead
(CP-8-12)
Dimensions shown in millimeters
Rev. D | Page 24 of 28
07-06-2011-A
PIN 1 INDEX
AREA
Data Sheet
ADA4528-1/ADA4528-2
2.44
2.34
2.24
3.10
3.00 SQ
2.90
0.50 BSC
8
5
1.70
1.60
1.50
EXPOSED
PAD
0.50
0.40
0.30
0.80
0.75
0.70
SEATING
PLANE
0.30
0.25
0.20
1
4
BOTTOM VIEW
TOP VIEW
0.05 MAX
0.02 NOM
COPLANARITY
0.08
0.203 REF
0.20 MIN
PIN 1
INDICATOR
(R 0.15)
FOR PROPER CONNECTION OF
THE EXPOSED PAD, REFER TO
THE PIN CONFIGURATION AND
FUNCTION DESCRIPTIONS
SECTION OF THIS DATA SHEET.
COMPLIANT TO JEDEC STANDARDS MO-229-WEED
11-28-2012-C
PIN 1 INDEX
AREA
Figure 76. 8-Lead Lead Frame Chip Scale Package [LFCSP_WD]
3 mm × 3 mm Body, Very Very Thin, Dual Lead
(CP-8-11)
Dimensions shown in millimeters
ORDERING GUIDE
Model 1
ADA4528-1ARMZ
ADA4528-1ARMZ-R7
ADA4528-1ARMZ-RL
ADA4528-1ACPZ-R2
ADA4528-1ACPZ-R7
ADA4528-1ACPZ-RL
ADA4528-2ARMZ
ADA4528-2ARMZ-R7
ADA4528-2ARMZ-RL
ADA4528-2ACPZ-R7
ADA4528-2ACPZ-RL
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
Package Description
8-Lead Mini Small Outline Package [MSOP]
8-Lead Mini Small Outline Package [MSOP]
8-Lead Mini Small Outline Package [MSOP]
8-Lead Lead Frame Chip Scale Package [LFCSP_WD]
8-Lead Lead Frame Chip Scale Package [LFCSP_WD]
8-Lead Lead Frame Chip Scale Package [LFCSP_WD]
8-Lead Mini Small Outline Package [MSOP]
8-Lead Mini Small Outline Package [MSOP]
8-Lead Mini Small Outline Package [MSOP]
8-Lead Lead Frame Chip Scale Package [LFCSP_WD]
8-Lead Lead Frame Chip Scale Package [LFCSP_WD]
Z = RoHS Compliant Part.
Rev. D | Page 25 of 28
Package Option
RM-8
RM-8
RM-8
CP-8-12
CP-8-12
CP-8-12
RM-8
RM-8
RM-8
CP-8-11
CP-8-11
Branding
A2R
A2R
A2R
A2R
A2R
A2R
A32
A32
A32
A32
A32
ADA4528-1/ADA4528-2
Data Sheet
NOTES
Rev. D | Page 26 of 28
Data Sheet
ADA4528-1/ADA4528-2
NOTES
Rev. D | Page 27 of 28
ADA4528-1/ADA4528-2
Data Sheet
NOTES
©2011–2013 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D09437-0-5/13(D)
Rev. D | Page 28 of 28