ANALOG DEVICES ADA4505-2 Service Manual

10 μA, Rail-to-Rail I/O, Zero Input

ADA4505-1/ADA4505-2/ADA4505-4

FEATURES

PSRR: 100 dB minimum
CMRR: 105 dB typical
Very low supply current: 10 μA per amplifier maximum

1.8 V to 5 V single-supply or ±0.9 V to ±2.5 V dual-supply operation
Rail-to-rail input and output
3 mV offset voltage maximum
Very low input bias current: 0.5 pA typical

APPLICATIONS

Pressure and position sensors
Remote security
Medical monitors
Battery-powered consumer equipment
Hazard detectors

GENERAL DESCRIPTION

The ADA4505-1/ADA4505-2/ADA4505-4 are single, dual, and
quad micropower amplifiers featuring rail-to-rail input and output
swings while operating from a single 1.8 V to 5 V power supply
or from dual ±0.9 V to ±2.5 V power supplies.

Employing a new circuit technology, these low cost amplifiers
offer zero input crossover distortion (excellent PSRR and CMRR
performance) and very low bias current, while operating with a
supply current of less than 10 µA per amplifier.

This combination of features makes the ADA4505-x amplifiers
ideal choices for battery-powered applications because they
minimize errors due to power supply voltage variations over the
lifetime of the battery and maintain high CMRR even for a rail­to-rail op amp.

Remote battery-powered sensors, handheld instrumentation
and consumer equipment, hazard detectors (for example, smoke,
fire, and gas), and patient monitors can benefit from the features
of the ADA4505-x amplifiers.

The ADA4505-x family is specified for both the industrial
temperature range (−40°C to +85°C) and the extended industrial
temperature range (−40°C to +125°C). The ADA4505-1 single
amplifier is available in a tiny 5-lead SOT-23 and a 6-ball WLCSP.
The ADA4505-2 dual amplifier is available in a standard 8-lead
MSOP and a 8-ball WLCSP. The ADA4505-4 quad amplifier is
available in a 14-lead TSSOP and a 14-ball WLCSP.

The ADA4505-x family is a member of a growing series of zero
crossover op amps offered by Analog Devices, Inc., including
the AD8505/AD8506/AD8508, which also operate from a single

1.8 V to 5 V power supply or from dual ±0.9 V to ±2.5 V power
supplies.

Rev. D

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.

Crossover Distortion Amplifiers

PIN CONFIGURATIONS

OUT

1

ADA4505-1

V–

2

TOP VIEW

(Not to Scal e)

+IN

3

Figure 1. 5-Lead SOT-23 (RJ-5) Figure 2. 8-Lead MSOP (RM-8)

BALL A1
INDICATOR

OUT V+

A1 A2

V–

B1 B2

+IN –IN

C1 C2

ADA4505-1

TOP VIEW

(BALL SIDE DOW N)

Not to Scal e

NC = NO CONNECT

Figure 3. 6-Ball WLCSP (CB-6-7) Figure 4. 8-Ball WLCSP (CB-8-2)

1

OUT A

2

–IN A

+IN A

+IN

–IN B

OUT B

V+

B

ADA4505-4

3

TOP VIEW

4

(Not to Scale)

5

6

7

Figure 5. 14-Lead TSSOP (RU-14) Figure 6. 14-Ball WLCSP (CB-14-1)

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] ©2008–2010 Analog Devices, Inc. All rights reserved.

NC

14

13

12

11

10

5

4

9

8

V+

–IN

07416-068

OUT D

–IN D

+IN D

V–

+IN C

–IN C

OUT C

OUT A

1

ADA4505-2

2

–IN A

+IN A

07416-001

07416-005

TOP VIEW

3

(Not to Scale)

V–

4

BALL A1
CORNER

OUT B V+ OUT A

A1 A2 A3

–IN B –IN A

B1 B3

+IN B V– +IN A

C1 C2 C3

ADA4505-2

TOP VIEW

(BALL SIDE DOWN)

BALL A1
INDICATOR

OUT D OUT A –IN A

A1

–IN D V– +IN A

B1

+IN D +IN B

C1 C3

+IN C V+ –IN B

D1

–IN C OUT C OUT B

E1

ADA4505-4

TOP VIEW

(BALL SIDE DO WN)

Not to Scale

8

7

6

5

A2

A3

B2

B3

D2

D3

E2

E3

V+

OUT B

–IN B

+IN B

07416-003

07416-004

07416-061

ADA4505-1/ADA4505-2/ADA4505-4

TABLE OF CONTENTS

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

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

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

Pin Configurations ........................................................................... 1

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

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

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

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

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

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

REVISION HISTORY

7/10—Rev. C to Rev. D

Added 6-Ball WLCSP, ADA4505-1 .................................. Universal

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

Changes to Large Signal Voltage Gain Parameter, Table 1 .......... 3

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

Changes to Large Signal Voltage Gain Parameter, Table 2 .......... 4

Changes to Thermal Resistance Section and Table 4 ................... 5

Updated Outline Dimensions ....................................................... 18

Changes to Ordering Guide .......................................................... 21

7/09—Rev. B to Rev. C

Added 5-Lead SOT-23 (ADA4505-1) ......................... Throughout

Changes to Supply Current per Amplifier Parameter, Table 1 ... 3
Changes to Supply Current per Amplifier Parameter, Table 2 ... 4

Changes to Figure 26 and Figure 29 ............................................... 9

Changes to Figure 31 and Figure 34 ............................................. 10

Changes to Figure 42 and Figure 45 ............................................. 12

Added Figure 49 and Figure 51; Renumbered Sequentially ..... 13

Updated Outline Dimensions ....................................................... 18

Changes to Ordering Guide .......................................................... 20

2/09—Rev. A to Rev. B

Added 14-Ball WLCSP (ADA4505-4) ........................ Throughout

Changes to Thermal Resistance Section ........................................ 5

Changes to Figure 17, Figure 18, Figure 20, and Figure 21 ......... 8

Changes to Figure 42 and Figure 45 ............................................. 12

Updated Outline Dimensions ....................................................... 18

Changes to Ordering Guide .......................................................... 20

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

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

Theory of Operation ...................................................................... 14

Applications Information .............................................................. 16

Pulse Oximeter Current Source ............................................... 16

Four-Pole, Low-Pass Butterworth Filter for Glucose Monitor

....................................................................................................... 17

Outline Dimensions ....................................................................... 18

Ordering Guide .......................................................................... 21

10/08—Rev. 0 to Rev. A

Added 8-Ball WLCSP (ADA4505-2) and 14-Lead TSSOP

(ADA4505-4) ................................................................. Throughout

Change to Features Section .............................................................. 1

Added Figure 2 and Figure 3; Renumbered Sequentially ............ 1

Changes to Table 1 ............................................................................. 3

Changes to Table 2 ............................................................................. 4

Changes to Thermal Resistance Section ........................................ 5

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

Changes to Figure 40 and Figure 43............................................. 12

Deleted Figure 46 and Figure 48; Renumbered Sequentially ... 13

Change to Theory of Operation Section ..................................... 14

Changes to Figure 52 ...................................................................... 16

Change to Four-Pole Low-Pass Butterworth Filter

for Glucose Monitor Section ......................................................... 17

Updated Outline Dimensions ....................................................... 18

Changes to Ordering Guide .......................................................... 19

7/08—Revision 0: Initial Version



Rev. D | Page 2 of 24

ADA4505-1/ADA4505-2/ADA4505-4

SPECIFICATIONS

ELECTRICAL CHARACTERISTICS—1.8 V OPERATION

VSY = 1.8 V, VCM = VSY/2, TA = 25°C, RL = 100 k to GND, unless otherwise specified.

Table 1.

Parameter Symbol Test Conditions/Comments Min Typ Max Unit

INPUT CHARACTERISTICS

Offset Voltage VOS 0 V ≤ VCM ≤ 1.8 V 0.5 3 mV

−40°C ≤ TA ≤ +125°C 4 mV
Input Bias Current IB 0.5 2 pA

−40°C ≤ TA ≤ +85°C 50 pA

−40°C ≤ TA ≤ +125°C 375 pA
Input Offset Current IOS 0.05 1 pA

−40°C ≤ TA ≤ +85°C 25 pA

−40°C ≤ TA ≤ +125°C 130 pA
Input Voltage Range −40°C ≤ TA ≤ +125°C 0 1.8 V
Common-Mode Rejection Ratio CMRR 0 V ≤ VCM ≤ 1.8 V 85 100 dB

−40°C ≤ TA ≤ +85°C 85 dB

−40°C ≤ TA ≤ +125°C 80 dB
Large Signal Voltage Gain AVO

0.05 V ≤ V
R

L

OUT

= 100 kΩ to VCM

≤ 1.75 V,

95 115 dB

−40°C ≤ TA ≤ +125°C 95 dB
Offset Voltage Drift

ΔV

OS

/ΔT

−40°C ≤ T

≤ +125°C 2.5 μV/°C

A

Input Resistance RIN 220 GΩ
Input Capacitance Differential Mode C
Input Capacitance Common Mode C

2.5 pF

INDM

4.7 pF

INCM

OUTPUT CHARACTERISTICS

Output Voltage High VOH R

= 100 kΩ to GND 1.78 1.79 V

L

−40°C ≤ TA ≤ +125°C 1.78 V
R

= 10 kΩ to GND 1.65 1.75 V

L

−40°C ≤ TA ≤ +125°C 1.65 V
Output Voltage Low VOL R

= 100 kΩ to VSY 2 5 mV

L

−40°C ≤ TA ≤ +125°C 5 mV
R

= 10 kΩ to VSY 12 25 mV

L

−40°C ≤ TA ≤ +125°C 25 mV
Short-Circuit Limit ISC V

= VSY or GND ±3.8 mA

OUT

POWER SUPPLY

Power Supply Rejection Ratio PSRR VSY = 1.8 V to 5 V 100 110 dB

−40°C ≤ TA ≤ +85°C 100 dB

−40°C ≤ TA ≤ +125°C 95 dB
Supply Current per Amplifier ISY V

= VSY/2

OUT

ADA4505-1 10 11.5 μA

–40°C ≤ TA ≤ +125°C 15 μA

ADA4505-2/ADA4505-4 7 10 μA

−40°C ≤ TA ≤ +125°C 15 μA

DYNAMIC PERFORMANCE

Slew Rate SR RL = 100 kΩ, CL = 20 pF, G = 1 6.5 mV/μs
Gain Bandwidth Product GBP RL = 1 MΩ, CL = 20 pF, G = 1 50 kHz
Phase Margin ΦM R

= 1 MΩ, CL = 20 pF, G = 1 52 Degrees

L

NOISE PERFORMANCE

Voltage Noise en p-p f = 0.1 Hz to 10 Hz 2.95 μV p-p
Voltage Noise Density en f = 1 kHz 65 nV/√Hz
Current Noise Density in f = 1 kHz 20 fA/√Hz

Rev. D | Page 3 of 24

ADA4505-1/ADA4505-2/ADA4505-4

ELECTRICAL CHARACTERISTICS—5 V OPERATION

VSY = 5 V, VCM = VSY/2, TA = 25°C, RL = 100 k to GND, unless otherwise specified.

Table 2.

Parameter Symbol Test Conditions/Comments Min Typ Max Unit

INPUT CHARACTERISTICS

Offset Voltage VOS 0 V ≤ VCM ≤ 5 V 0.5 3 mV

−40°C ≤ TA ≤ +125°C 4 mV
Input Bias Current IB 0.5 2 pA

−40°C ≤ TA ≤ +85°C 50 pA

−40°C ≤ TA ≤ +125°C 375 pA
Input Offset Current IOS 0.05 1 pA

−40°C ≤ TA ≤ +85°C 25 pA

−40°C ≤ TA ≤ +125°C 130 pA
Input Voltage Range −40°C ≤ TA ≤ +125°C 0 5 V
Common-Mode Rejection Ratio CMRR 0 V ≤ VCM ≤ 5 V 90 105 dB

−40°C ≤ TA ≤ +85°C 90 dB

−40°C ≤ TA ≤ +125°C 85 dB
Large Signal Voltage Gain AVO

0.05 V ≤ V
R

= 100 kΩ to VCM

L

≤ 4.95 V,

OUT

−40°C ≤ TA ≤ +125°C 100 dB
Offset Voltage Drift

ΔV

OS

/ΔT

−40°C ≤ T

≤ +125°C 2 μV/°C

A

Input Resistance RIN 220 GΩ
Input Capacitance Differential Mode C
Input Capacitance Common Mode C

2.5 pF

INDM

4.7 pF

INCM

OUTPUT CHARACTERISTICS

Output Voltage High VOH R

= 100 kΩ to GND 4.98 4.99 V

L

−40°C ≤ TA ≤ +125°C 4.98 V
R

= 10 kΩ to GND 4.9 4.95 V

L

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

= 100 kΩ to VSY 2 5 mV

L

−40°C ≤ TA ≤ +125°C 5 mV
R

= 10 kΩ to VSY 10 25 mV

L

−40°C ≤ TA ≤ +125°C 25 mV
Short-Circuit Limit ISC V

= VSY or GND ±40 mA

OUT

POWER SUPPLY

Power Supply Rejection Ratio PSRR VSY = 1.8 V to 5 V 100 110 dB

−40°C ≤ TA ≤ +85°C 100 dB

−40°C ≤ TA ≤ +125°C 95 dB
Supply Current per Amplifier ISY V

= VSY/2

OUT

ADA4505-1 9 10.5 μA

–40°C ≤ TA ≤ +125°C 15 μA

ADA4505-2/ADA4505-4 7 10 μA

−40°C ≤ TA ≤ +125°C 15 μA

DYNAMIC PERFORMANCE

Slew Rate SR RL = 100 kΩ, CL = 20 pF, G = 1 6 mV/μs
Gain Bandwidth Product GBP RL = 1 MΩ, CL = 20 pF, G = 1 50 kHz
Phase Margin ΦM R

= 1 MΩ, CL = 20 pF, G = 1 52 Degrees

L

NOISE PERFORMANCE

Voltage Noise en p-p f = 0.1 Hz to 10 Hz 2.95 μV p-p
Voltage Noise Density en f = 1 kHz 65 nV/√Hz
Current Noise Density in f = 1 kHz 20 fA/√Hz

Rev. D | Page 4 of 24

105 120 dB

ADA4505-1/ADA4505-2/ADA4505-4

ABSOLUTE MAXIMUM RATINGS

Table 3.

Parameter Rating

Supply Voltage 5.5 V
Input Voltage ±VSY ± 0.1 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

Input pins have clamp diodes to the supply pins. Limit input current to 10 mA

or less whenever the input signal exceeds the power supply rail by 0.1 V.

2

Diff erential input voltage is limited to 5 V or the supply voltage, whichever is less.

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 in a circuit board for surface-mount packages with its
exposed paddle soldered to a pad (if applicable). Simulated
thermal numbers on a 4-layer (2S/2P) JEDEC standard thermal
test board, unless otherwise specified.

Table 4.

Package Type θJA θJC Unit

5-Lead SOT-23 (RJ-5) 190 92 °C/W
6-Ball WLCSP (CB-6-7) 105 2.6 °C/W
8-Lead MSOP (RM-8) 142 45 °C/W
8-Ball WLCSP (CB-8-2) 82 N/A °C/W
14-Lead TSSOP (RU-14) 112 35 °C/W
14-Ball WLCSP (CB-14-1) 64 N/A °C/W

ESD CAUTION

Rev. D | Page 5 of 24

ADA4505-1/ADA4505-2/ADA4505-4

TYPICAL PERFORMANCE CHARACTERISTICS

TA = 25°C, unless otherwise noted.

140

120

VSY = 1.8V

= VSY/2

V

CM

140

120

VSY = 5V
V

= VSY/2

CM

100

80

60

40

NUMBER OF AMPLIFIERS

20

0

–3.0 –2.5 –2.0 –1.5 –1.0 –0. 5 0 0.5 1.0 1.5 2.0 2. 5 3.0

V

(mV)

OS

Figure 7. Input Offset Voltage Distribution

NUMBER OF AMPL IFIERS

14

12

10

8

6

4

2

VSY = 1.8V
–40°C  T

A

 125°C

100

80

60

40

NUMBER OF AMPLIFIERS

20

0

07416-007

–3.0 –2.5 –2.0 –1.5 –1.0 –0. 5 0 0.5 1.0 1.5 2.0 2. 5 3.0

V

(mV)

OS

07416-008

Figure 10. Input Offset Voltage Distribution

NUMBER OF AMPLIFIERS

14

12

10

8

6

4

2

VSY = 5V
–40°C  T

 125°C

A

0

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0

TCV

OS

(µV/°C)

Figure 8. Input Offset Voltage Drift Distribution

1500

VSY = 1.8V

1000

500

(µV)

0

OS

V

–500

–1000

–1500

0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8

V

(V)

CM

Figure 9. Input Offset Voltage vs. Common-Mode Voltage

07416-009

DEVICE 1

DEVICE 2

DEVICE 3

DEVICE 4

DEVICE 5

DEVICE 6

DEVICE 7

DEVICE 8

DEVICE 9

DEVICE 10

07416-011

Rev. D | Page 6 of 24

0

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5. 5 6.0

TCV

OS

(µV/°C)

Figure 11. Input Offset Voltage Drift Distribution

1500

VSY = 5V

1000

500

0

(µV)

OS

V

–500

–1000

–1500

012345

V

(V)

CM

Figure 12. Input Offset Voltage vs. Common-Mode Voltage

07416-010

DEVICE 1

DEVICE 2

DEVICE 3

DEVICE 4

DEVICE 5

DEVICE 6

DEVICE 7

DEVICE 8

DEVICE 9

DEVICE 10

07416-012

ADA4505-1/ADA4505-2/ADA4505-4

TA = 25°C, unless otherwise noted.

1000

VSY = 1.8V

I

B+

I

B–

1000

VSY = 5V

I

B+

I

B–

100

10

(pA)

B

I

1

0.1
0 25 50 75 100 125

TEMPERATURE (° C)

Figure 13. Input Bias Current vs. Temperature

1000

100

(pA)

B

I

125°C

105°C

10

85°C

1

25°C

VSY = 1.8V
I

B+

AND I

100

10

(pA)

B

I

1

0.1

07416-013

0 25 50 75 100 125

TEMPERATURE ( °C)

07416-015

Figure 16. Input Bias Current vs. Temperature

1000

B–

125°C

100

105°C

10

(pA)

B

85°C

I

1

25°C

VSY = 5V

AND I

I

B+

B–

0.1
0 0. 2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8

V

(V)

CM

Figure 14. Input Bias Current vs. Common-Mode Voltage and Temperature

10k

VSY = 1.8V

1k

100

) TO SUPPLY RAIL (mV)

10

OH

1

–40°C

0.1

OUTPUT VOLTAGE (V

0.01

0.001 0.01 0.1

LOAD CURRENT (mA)

1101

+25°C
+85°C
+125°C

00

Figure 15. Output Voltage (VOH) to Supply Rail vs. Load Current

and Temperature

0.1
012 345

07416-014

V

(V)

CM

07416-016

Figure 17. Input Bias Current vs. Common-Mode Voltage and Temperature

10k

VSY = 5V

1k

100

) TO SUPPLY RAIL (mV)

10

OH

1

–40°C

0.1

OUTPUT VO LTAGE (V

0.01

0.001 0.01 0.1

07416-017

LOAD CURRENT (mA)

1101

+25°C
+85°C
+125°C

00

07416-018

Figure 18. Output Voltage (VOH) to Supply Rail vs. Load Current

and Temperature

Rev. D | Page 7 of 24

ADA4505-1/ADA4505-2/ADA4505-4

TA = 25°C, unless otherwise noted.

10k

VSY = 1.8V

10k

VSY = 5V

1k

100

) TO SUPPLY RAIL (mV)

10

OL

1

–40°C

0.1

OUTPUT VOL TAGE (V

0.01

0.001 0.01 0.1

LOAD CURRENT (mA)

1 10 100

+25°C
+85°C
+125°C

Figure 19. Output Voltage (VOL) to Supply Rail vs. Load Current

and Temperature

1.800

RL = 100k

1.795

] (V)

OH

1.790

1.785

OUTPUT VOLTAGE [V

1.780

VSY = 1.8V

1.775
–40 –25 –10 5 20 35 50 65 80 95 110 125

RL = 10k

TEMPERATURE (° C)

Figure 20. Output Voltage (VOH) vs. Temperature

25

VSY = 1.8V

1k

100

) TO SUPPLY RAIL (mV)

10

OL

1

–40°C

0.1

OUTPUT VOL TAGE (V

0.01

07416-019

0.001 0.01 0.1

LOAD CURRENT (mA)

1 10 100

+25°C
+85°C
+125°C

07416-020

Figure 22. Output Voltage (VOL) to Supply Rail vs. Load Current

and Temperature

5.000

4.995

] (V)

4.990

OH

4.985

4.980

OUTPUT VO LTAGE [V

4.975

VSY = 5V

4.970
–40 –25 –10 5 20 35 50 65 80 95 110 125

07416-021

RL = 100k

RL = 10k

TEMPERATURE ( °C)

07416-022

Figure 23. Output Voltage (VOH) vs. Temperature

25

VSY = 5V

20

] (mV)

OL

15

10

OUTPUT VOLTAGE [V

5

0
–40 –25 –10 5 20 35 50 65 80 95 110 125

RL = 10k

RL = 100k

TEMPERATURE (° C)

Figure 21. Output Voltage (VOL) vs. Temperature

07416-023

20

] (mV)

OL

15

10

OUTPUT VO LTAGE [V

5

0
–40–25–105 203550658095110125

RL = 10k

RL = 100k

TEMPERATURE (° C)

Figure 24. Output Voltage (VOL) vs. Temperature

07416-024

Rev. D | Page 8 of 24