ANALOG DEVICES ADA4051-1, ADA4051-2 Service Manual

1.8 V, Micropower, Zero-Drift,

FEATURES

Very low supply current: 13 μA typical
Low offset voltage: 15 μV maximum
Offset voltage drift: 20 nV/°C
Single-supply operation: 1.8 V to 5.5 V
High PSRR: 110 dB minimum
High CMRR: 110 dB minimum
Rail-to-rail input/output
Unity-gain stable
Extended industrial temperature range

APPLICATIONS

Pressure and position sensors
Temperature measurements
Electronic scales
Medical instrumentation
Battery-powered equipment
Handheld test equipment

Rail-to-Rail Input/Output Op Amp

ADA4051-1/ADA4051-2

PIN CONFIGURATION

1

OUT

ADA4051-1

V–

2

TOP VIEW

(Not to Scale)

+IN

3

Figure 1. 5-Lead SOT-23 (RJ-5)

1

+IN

ADA4051-1

V–

2

TOP VIEW

(Not to Scale)

–IN

3

Figure 2. 5-Lead SC-70 (KS-5)

OUT A

1

ADA4051-2

2

–IN A
+IN A

V–

TOP VIEW

3

(Not to Scale)

4

Figure 3. 8-Lead MSOP (RM-8)

5

4

8
7
6
5

5

4

V+

OUT

V+
OUT B
–IN B
+IN B

V+

–IN

08056-064

08056-066

08056-001

GENERAL DESCRIPTION

The ADA4051-1/ADA4051-2 are CMOS, micropower, zero­drift operational amplifiers utilizing an innovative chopping
technique. These amplifiers feature rail-to-rail input/output
swing and extremely low offset voltage while operating from a

1.8 V to 5.5 V power supply. In addition, these amplifiers offer
high power supply rejection ratio (PSRR) and common-mode
rejection ratio (CMRR) while operating with a typical supply
current of 13 μA per amplifier. This combination of features
makes the ADA4051-1/ADA4051-2 amplifiers ideal choices for
battery-powered applications where high precision and low
power consumption are important.

PIN 1

1OUT A

INDICATOR

2–IN A

ADA4051-2

3+IN A

TOP VIEW

(Not to Scale)

4V–

NOTES

1. IT IS RE COMMENDED THAT THE
EXPOSED PAD BE CO NNE CTED TO V–.

8V+
7OUT B
6 –IN B
5 +IN B

08056-065

Figure 4. 8-Lead LFCSP (CP-8-2)

The ADA4051-1/ADA4051-2 are specified for the extended
industrial temperature range of −40°C to +125°C. The ADA4051-1
amplifier is available in 5-lead SOT-23 and 5-lead SC-70 packages.
The ADA4051-2 amplifier is available in 8-lead MSOP and 8-lead
LFCSP packages.

The ADA4051-1/ADA4051-2 are members of a growing series
of zero-drift op amps offered by Analog Devices, Inc. Refer to
Table 1 for a list of these devices.

Table 1. Op Amps

Supply Low Power, 5 V 5 V 16 V

Single AD8538 AD8628 AD8638
Dual AD8539 AD8629 AD8639
Quad AD8630

Rev. B

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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: [phone] www.analog.com
Fax: [phone] ©2009–2010 Analog Devices, Inc. All rights reserved.

ADA4051-1/ADA4051-2

TABLE OF CONTENTS

Features .............................................................................................. 1

Applications ....................................................................................... 1 

Pin Configuration ............................................................................. 1

General Description ......................................................................... 1

Revision History ............................................................................... 2

Specifications ..................................................................................... 3

Electrical Characteristics—1.8 V Operation ............................ 3

Electrical Characteristics—5 V Operation................................ 4

Absolute Maximum Ratings ............................................................ 5

REVISION HISTORY

1/10—Rev. A to Rev. B

Added ADA4051-1, 5-Lead SC-70 Package .................... Universal

Added Figure 2; Renumbered Sequentially .................................. 1

Changes to Figure 4 and General Description Section ............... 1

Changes to Electrical Characteristics—1.8 V Operation Section

and Table 2 ......................................................................................... 3

Changes to Electrical Characteristics—5 V Operation Section

and Table 3 ......................................................................................... 4

Changes to Table 5 ............................................................................ 5

Updated Outline Dimensions ....................................................... 17

Changes to Ordering Guide .......................................................... 18

10/09—Rev. 0 to Rev. A

Added ADA4051-1, 5-Lead SOT-23 Package ................. Universal

Added ADA4051-2, 8-Lead LFCSP Package .................. Universal

Changes to the Features and General Description Section,

Added Figure 1 and Figure 3 ........................................................... 1

Moved Electrical Characteristics—1.8 V Operation Section .... 3

Changes to Offset Voltage Parameter and Supply Current per

Amplifier Parameter, Table 2 .......................................................... 3

Moved Electrical Characteristics—5 V Operation Section ........ 4

Changes to Offset Voltage Parameter and Supply Current per

Amplifier Parameter, Table 2 .......................................................... 4

Changes to Thermal Resistance Section and Table 5 ................... 5

Changes to Figure 22 and Figure 25 ............................................... 9

Changes to Theory of Operation Section .................................... 15

Updated Outline Dimensions ....................................................... 17

Changes to Ordering Guide .......................................................... 18

7/09—Revision 0: Initial Version

Thermal Resistance .......................................................................5

Power Sequencing .........................................................................5

ESD Caution...................................................................................5

Typical Performance Characteristics ..............................................6

Theory of Operation ...................................................................... 15

Input Voltage Range ................................................................... 16

Output Phase Reversal ............................................................... 16

Outline Dimensions ....................................................................... 17

Ordering Guide .......................................................................... 18

Rev. B | Page 2 of 20

ADA4051-1/ADA4051-2

SPECIFICATIONS

ELECTRICAL CHARACTERISTICS—1.8 V OPERATION

VSY = 1.8 V, VCM = VSY/2 V, TA = 25°C, RL = 100 kΩ to GND, unless otherwise noted.

Table 2.

Parameter Symbol Test Conditions/Comments Min Typ Max Unit

INPUT CHARACTERISTICS

Offset Voltage VOS

ADA4051-2 0 V ≤ VCM ≤ 1.8 V 2 15 μV

ADA4051-1 0 V ≤ VCM ≤ 1.8 V 2 17 μV
Offset Voltage Drift ∆VOS/∆T −40°C ≤ TA ≤ +125°C 0.02 0.1 μV/°C
Input Bias Current IB 5 50 pA

−40°C ≤ TA ≤ +125°C 200 pA
Input Offset Current IOS 10 100 pA

−40°C ≤ TA ≤ +125°C 150 pA
Input Voltage Range −40°C ≤ TA ≤ +125°C 0 1.8 V
Common-Mode Rejection Ratio CMRR 0 V ≤ VCM ≤ 1.8 V 105 125 dB

−40°C ≤ TA ≤ +125°C 100 dB
Large-Signal Voltage Gain AVO

= 10 kΩ to VCM,

R

L

0.1 V ≤ V

≤ VSY − 0.1 V

OUT

−40°C ≤ TA ≤ +125°C 100 dB
Input Resistance RIN 8 MΩ
Input Capacitance, Differential Mode C
Input Capacitance, Common Mode C

2 pF

INDM

5 pF

INCM

OUTPUT CHARACTERISTICS

Output Voltage High VOH R

= 100 kΩ to VCM 1.796 1.799 V

L

−40°C ≤ TA ≤ +125°C 1.79 V
R

= 10 kΩ to VCM 1.76 1.796 V

L

−40°C ≤ TA ≤ +125°C 1.7 V
Output Voltage Low VOL R

= 100 kΩ to VCM 1 3 mV

L

−40°C ≤ TA ≤ +125°C 9 mV
R

= 10 kΩ to VCM 3 20 mV

L

−40°C ≤ TA ≤ +125°C 40 mV
Short-Circuit Current ISC V
Closed-Loop Output Impedance Z

f = 1 kHz, G = 10 1 Ω

OUT

= VSY or GND 13 mA

OUT

POWER SUPPLY

Power Supply Rejection Ratio PSRR 1.8 V ≤ VSY ≤ 5.5 V 110 135 dB

−40°C ≤ TA ≤ +125°C 106 dB
Supply Current per Amplifier ISY

ADA4051-2 V

ADA4051-1 V

= VSY/2 13 17 μA

OUT

= VSY/2 15 18 μA

OUT

−40°C ≤ TA ≤ +125°C 20 μA

DYNAMIC PERFORMANCE

Slew Rate SR+ RL = 10 kΩ, CL = 100 pF, G = 1 0.04 V/μs
SR− RL = 10 kΩ, CL = 100 pF, G = 1 0.03 V/μs
Settling Time tS

To 0.1%, V
R

= 10 kΩ, CL = 100 pF

L

= 1 V p-p,

IN

Gain Bandwidth Product GBP CL = 100 pF, G = 1 115 kHz
Phase Margin ΦM C

= 100 pF, G = 1 40 Degrees

L

Channel Separation CS VIN = 1.7 V, f = 100 Hz 140 dB

NOISE PERFORMANCE

Voltage Noise en p-p f = 0.1 Hz to 10 Hz 1.96 μV p-p
Voltage Noise Density en f = 1 kHz 95 nV/√Hz
Current Noise Density in f = 1 kHz 100 fA/√Hz

Rev. B | Page 3 of 20

106 130 dB

120 μs

ADA4051-1/ADA4051-2

ELECTRICAL CHARACTERISTICS—5 V OPERATION

VSY = 5.0 V, VCM = VSY/2 V, TA = 25°C, RL = 100 kΩ to GND, unless otherwise noted.

Table 3.

Parameter Symbol Test Conditions/Comments Min Typ Max Unit

INPUT CHARACTERISTICS

Offset Voltage VOS

ADA4051-2 0 V ≤ VCM ≤ 5 V 2 15 μV

ADA4051-1 0 V ≤ VCM ≤ 5 V 2 17 μV
Offset Voltage Drift ∆VOS/∆T −40°C ≤ TA ≤ +125°C 0.02 0.1 μV/°C
Input Bias Current IB 20 70 pA

−40°C ≤ TA ≤ +125°C 200 pA
Input Offset Current IOS 40 100 pA

−40°C ≤ TA ≤ +125°C 150 pA
Input Voltage Range −40°C ≤ TA ≤ +125°C 0 5 V
Common-Mode Rejection Ratio CMRR 0 V ≤ VCM ≤ 5 V 110 135 dB

−40°C ≤ TA ≤ +125°C 106 dB
Large-Signal Voltage Gain AVO

= 10 kΩ to VCM,

R

L

0.1 V ≤ V

≤ VSY − 0.1 V

OUT

−40°C ≤ TA ≤ +125°C 106 dB
Input Resistance RIN 8 MΩ
Input Capacitance, Differential Mode C
Input Capacitance, Common Mode C

2 pF

INDM

5 pF

INCM

OUTPUT CHARACTERISTICS

Output Voltage High VOH R

= 100 kΩ to VCM 4.996 4.998 V

L

−40°C ≤ TA ≤ +125°C 4.985 V
R

= 10 kΩ to VCM 4.96 4.99 V

L

−40°C ≤ TA ≤ +125°C 4.9 V
Output Voltage Low VOL R

= 100 kΩ to VCM 1 4 mV

L

−40°C ≤ TA ≤ +125°C 13 mV
R

= 10 kΩ to VCM 9 30 mV

L

−40°C ≤ TA ≤ +125°C 90 mV
Short-Circuit Current ISC V
Closed-Loop Output Impedance Z

f = 1 kHz, G = 10 1 Ω

OUT

= VSY or GND 15 mA

OUT

POWER SUPPLY

Power Supply Rejection Ratio PSRR 1.8 V ≤ VSY ≤ 5.5 V 110 135 dB

−40°C ≤ TA ≤ +125°C 106 dB
Supply Current per Amplifier ISY

ADA4051-2 V

ADA4051-1 V

= VSY/2 13 17 μA

OUT

= VSY/2 15 18 μA

OUT

−40°C ≤ TA ≤ +125°C 20 μA

DYNAMIC PERFORMANCE

Slew Rate SR+ RL = 10 kΩ, CL = 100 pF, G = 1 0.06 V/μs
SR− RL = 10 kΩ, CL = 100 pF, G = 1 0.04 V/μs
Settling Time tS

To 0.1%, V
R

= 10 kΩ, CL = 100 pF

L

= 1 V p-p,

IN

Gain Bandwidth Product GBP CL = 100 pF, G = 1 125 kHz
Phase Margin ΦM C

= 100 pF, G = 1 40 Degrees

L

Channel Separation CS VIN = 4.99 V, f = 100 Hz 140 dB

NOISE PERFORMANCE

Voltage Noise en p-p f = 0.1 Hz to 10 Hz 1.96 μV p-p
Voltage Noise Density en f = 1 kHz 95 nV/√Hz
Current Noise Density in f = 1 kHz 100 fA/√Hz

Rev. B | Page 4 of 20

115 135 dB

110 μs

ADA4051-1/ADA4051-2

ABSOLUTE MAXIMUM RATINGS

Table 4.

Parameter Rating

Supply Voltage 6 V

Input Voltage ±VSY ± 0.3 V

Input Current1 ±10 mA

Differential Input Voltage2 ±VSY

Output Short-Circuit Duration to GND Indefinite

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

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.

2

Inputs are protected against high differential voltages by internal series

1.33 kΩ resistors and back-to-back diode-connected N-MOSFETs (with a
typical VT of 0.7 V for VCM of 0 V).

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.

THERMAL RESISTANCE

θJA is specified for the worst-case conditions, that is, a device
soldered on a circuit board for surface-mount packages with its
exposed paddle soldered to a pad, if applicable. Tabl e 5 shows
simulated thermal values for a 4-layer (2S2P) JEDEC standard
thermal test board, unless otherwise specified.

Table 5. Thermal Resistance

Package Type θJA θ

5-Lead SOT-23 (RJ-5) 190 92 °C/W
5-Lead SC-70 (KS-5) 534 173 °C/W
8-Lead MSOP (RM-8) 142 45 °C/W
8-Lead LFCSP (CP-8-2) 77 14 °C/W

Unit

JC

POWER SEQUENCING

The op amp supplies must be established simultaneously with
or before any input signals are applied. If this is not possible, the
input current must be limited to 10 mA.

ESD CAUTION

Rev. B | Page 5 of 20

ADA4051-1/ADA4051-2

TYPICAL PERFORMANCE CHARACTERISTICS

TA = 25°C, unless otherwise noted.

300

250

VSY = 1.8V
V

= VSY/2

CM

300

250

VSY = 5V
V

= VSY/2

CM

200

150

100

NUMBER OF AMPLIF IERS

50

0

–10–8–6–4–20246810

VOS (µV)

Figure 5. Input Offset Voltage Distribution Figure 8. Input Offset Voltage Distribution

NUMBER OF AMPLIF IERS

10

8

6

4

2

= 1.8V

V

SY

–40°C  T

 +125°C

A

200

150

100

NUMBER OF AMPLIFI ERS

50

0

–10–8–6–4–20246810

08056-002

8

6

4

NUMBER OF AMPLIF IERS

2

VOS (µV)

–40°C  T

VSY = 5V

 125°C

A

08056-005

0

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10

TCVOS (µV/°C)

Figure 6. Input Offset Voltage Drift Distribution with Temperature

15

VSY = 1.8V

10

5

(µV)

0

OS

V

–5

–10

–15

0 0.3 0.6 0.9 1.2 1.5 1.8

VCM (V)

DEVICE 1
DEVICE 2
DEVICE 3
DEVICE 4
DEVICE 5
DEVICE 6
DEVICE 7
DEVICE 8
DEVICE 9
DEVICE 10

Figure 7. Input Offset Voltage vs. Input Common-Mode Voltage

08056-003

08056-004

Rev. B | Page 6 of 2

0

0 0.010.020.030.040.050.060.070.080.090.10

TCVOS (µV/°C)

Figure 9. Input Offset Voltage Drift Distribution with Temperature

15

= 5V

V

SY

10

5

(µV)

0

OS

V

–5

–10

–15

012345

(V)

V

CM

DEVICE 1
DEVICE 2
DEVICE 3
DEVICE 4
DEVICE 5
DEVICE 6
DEVICE 7
DEVICE 8
DEVICE 9
DEVICE 10

Figure 10. Input Offset Voltage vs. Input Common-Mode Voltage

0

08056-006

6-007
0805