ANALOG DEVICES AD 8544 ARUZ Datasheet

CMOS Rail-to-Rail General-Purpose

O

O

FEATURES

Single-supply operation: 2.7 V to 5.5 V
Low supply current: 45 μA/amplifier
Wide bandwidth: 1 MHz
No phase reversal
Low input currents: 4 pA
Unity gain stable
Rail-to-rail input and output
Qualified for automotive applications

APPLICATIONS

ASIC input or output amplifiers
Sensor interfaces
Piezoelectric transducer amplifiers
Medical instrumentation
Mobile communications
Audio outputs
Portable systems

GENERAL DESCRIPTION

The AD8541/AD8542/AD8544 are single, dual, and quad rail­to-rail input and output, single-supply amplifiers featuring very
low supply current and 1 MHz bandwidth. All are guaranteed to
operate from a 2.7 V single supply as well as a 5 V supply. These
parts provide 1 MHz bandwidth at a low current consumption
of 45 µA per amplifier.

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 A per amplifier, ideal for battery
operation.

Rail-to-rail inputs and outputs are useful to designers buffering
ASICs in single-supply systems. The AD8541/AD8542/AD8544
are optimized to maintain high gains at lower supply voltages,
making them useful for active filters and gain stages.

The AD8541/AD8542/AD8544 are specified over the extended
industrial temperature range (–40°C to +125°C). The AD8541
is available in 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 surface­mount packages. All MSOP, SC70, and SOT versions are available
in tape and reel only. See the Ordering Guide for automotive
models.

Amplifiers

AD8541/AD8542/AD8544

PIN CONFIGURATIONS

+IN A

V–

AD8541

1

2

3

OUT A

Figure 1. 5-Lead SC70 and 5-Lead SOT-23

(KS and RJ Suffixes)

1

NC

AD8541

2

–IN A

3

+IN A

4

V–

NC = NO CONNECT

Figure 2. 8-Lead SOIC

(R Suffix)

OUT A

–IN A

+IN A

V–

Figure 3. 8-Lead SOIC, 8-Lead MSOP, and 8-Lead TSSOP

AD8542

1

2

3

4

(R, RM, and RU Suffixes)

1

UT A

2

–IN A

3

+IN A

AD8544

4

V+

5

+IN B

6

–IN B

7

UT B

Figure 4. 14-Lead SOIC and 14-Lead TSSOP

(R and RU Suffixes)

V+

5

–IN A

4

0935-001

8

NC

V+

7

OUT A

6

NC

5

00935-002

8

V+

OUT B

7

6

–IN B

5

+IN B

00935-003

14

OUT D

–IN D

13

12

+IN D

11

V–

10

+IN C

9

–IN C

8

OUT C

0935-004

Rev. G

Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Anal og Devices for its use, nor for any infringements of patents or ot her
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] ©2008–2011 Analog Devices, Inc. All rights reserved.

AD8541/AD8542/AD8544

TABLE OF CONTENTS

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

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

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

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

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

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

Electrical Characteristics ............................................................. 3

Absolute Maximum Ratings............................................................ 6

Thermal Resistance ...................................................................... 6

ESD Caution.................................................................................. 6

Typical Performance Characteristics ............................................. 7

REVISION HISTORY

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

Theory of Operation ...................................................................... 13

Notes on the AD854x Amplifiers............................................. 13

Applications..................................................................................... 14

Notch Filter ................................................................................. 14

Comparator Function................................................................ 14

Photodiode Application ............................................................ 15

Outline Dimensions....................................................................... 16

Ordering Guide .......................................................................... 19

Automotive Products................................................................. 19

1/07—Rev. D to Rev. E

Updated Format.................................................................. Universal

Changes to Photodiode Application Section .............................. 14

Changes to Ordering Guide.......................................................... 17

8/04—Rev. C to Rev. D

Changes to Ordering Guide.............................................................5

Changes to Figure 3........................................................................ 10

Updated Outline Dimensions....................................................... 12

1/03—Rev. B to Rev. C

Updated Format.................................................................. Universal

Changes to General Description .....................................................1

Changes to Ordering Guide.............................................................5

Changes to Outline Dimensions .................................................. 12

Rev. G | Page 2 of 20

AD8541/AD8542/AD8544

SPECIFICATIONS

ELECTRICAL CHARACTERISTICS

VS = 2.7 V, VCM = 1.35 V, TA = 25°C, unless otherwise noted.

Table 1.

Parameter 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 ∆VOS/∆T −40°C ≤ TA ≤ +125°C 4 µV/°C
Bias Current Drift ∆IB/∆T −40°C ≤ TA ≤ +85°C 100 fA/°C

−40°C ≤ TA ≤ +125°C 2000 fA/°C
Offset Current Drift ∆IOS/∆T −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 I
I
Closed-Loop Output Impedance Z

POWER SUPPLY

Power Supply Rejection Ratio PSRR VS = 2.5 V to 6 V 65 76 dB

−40°C ≤ TA ≤ +125°C 60 dB
Supply Current/Amplifier ISY VO = 0 V 38 55 µA

−40°C ≤ TA ≤ +125°C 75 µA
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

NOISE PERFORMANCE

Voltage Noise Density en f = 1 kHz 40 nV/√Hz
e
Current Noise Density in <0.1 pA/√Hz

V

OUT

±20 mA

SC

f = 200 kHz, AV = 1 50 Ω

OUT

= VS − 1 V 15 mA

OUT

63 Degrees

Φ

M

f = 10 kHz 38 nV/√Hz

n

Rev. G | Page 3 of 20

AD8541/AD8542/AD8544

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 ∆VOS/∆T −40°C ≤ TA ≤ +125°C 4 V/°C
Bias Current Drift ∆IB/∆T −40°C ≤ TA ≤ +85°C 100 fA/°C

−40°C ≤ TA ≤ +125°C 2000 fA/°C
Offset Current Drift ∆IOS/∆T −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 I
I
Closed-Loop Output Impedance Z

POWER SUPPLY

Power Supply Rejection Ratio PSRR VS = 2.5 V to 6 V 65 76 dB

−40°C ≤ TA ≤ +125°C 60 dB
Supply Current/Amplifier ISY VO = 0 V 40 60 µA

−40°C ≤ TA ≤ +125°C 75 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
e
Current Noise Density in <0.1 pA/√Hz

V

OUT

±25 mA

SC

f = 200 kHz, AV = 1 50 Ω

OUT

f = 10 kHz 38 nV/√Hz

n

= VS − 1 V 18 mA

OUT

Rev. G | Page 4 of 20

AD8541/AD8542/AD8544

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 ∆VOS/∆T −40°C ≤ TA ≤ +125°C 4 V/°C
Bias Current Drift ∆IB/∆T −40°C ≤ TA ≤ +85°C 100 fA/°C

−40°C ≤ TA ≤ +125°C 2000 fA/°C
Offset Current Drift ∆IOS/∆T −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 I
I
Closed-Loop Output Impedance Z

POWER SUPPLY

Power Supply Rejection Ratio PSRR VS = 2.5 V to 6 V 65 76 dB

−40°C ≤ TA ≤ +125°C 60 dB
Supply Current/Amplifier ISY VO = 0 V 45 65 µA

−40°C ≤ TA ≤ +125°C 85 µA

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
e
Current Noise Density in <0.1 pA/√Hz

V

OUT

±60 mA

SC

f = 200 kHz, AV = 1 45 Ω

OUT

f = 10 kHz 38 nV/√Hz

n

= VS − 1 V 30 mA

OUT

Rev. G | Page 5 of 20

AD8541/AD8542/AD8544

ABSOLUTE MAXIMUM RATINGS

Table 4.

Parameter Rating

Supply Voltage (VS) 6 V
Input Voltage GND to VS
Differential Input Voltage1 ±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.

THERMAL RESISTANCE

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 θ

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

Unit

JC

ESD CAUTION

Rev. G | Page 6 of 20

AD8541/AD8542/AD8544

TYPICAL PERFORMANCE CHARACTERISTICS

180

160

140

120

100

80

60

NUMBER OF AMPL IFIE RS

40

20

0

–4.5 –3.5 4. 5–2.5 –1.5 –0.5 0.5

INPUT OFFSET VOLTAGE (mV)

Figure 5. Input Offset Voltage Distribution

1.0

VS = 2.7V AND 5V

0.5

V

= VS/2

CM

0

–0.5

–1.0

–1.5

–2.0

–2.5

INPUT OFFSET VOLTAGE (mV)

–3.0

–3.5

–4.0

–55 –35 –15

5 25456585105125

TEMPERATURE (°C)

Figure 6. Input Offset Voltage vs. Temperature

VS=5V
V

=2.5V

CM

T

= 25°C

A

1.5 2.5 3.5

00935-005

145

00935-006

400

VS = 2.7V AND 5V
V

= VS/2

CM

350

300

250

200

150

100

INPUT BIAS CURRENT (pA)

50

0

–40 –20 0 20 40 60 80 100 120 140

TEMPERATURE (° C)

Figure 8. Input Bias Current vs. Temperature

7

VS = 2.7V AND 5V

= VS/2

V

6

CM

5

4

3

2

1

INPUT OFFSET CURRENT ( pA)

0

–1

–55 –35 –15 5 25 45 65 85 105 125 145

TEMPERATURE (° C)

Figure 9. Input Offset Current vs. Temperature

00935-008

00935-009

9

VS = 2.7V AND 5V

8

V

= VS/2

CM

7

6

5

4

3

INPUT BIAS CURRE NT (pA)

2

1

0

–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

00935-007

Rev. G | Page 7 of 20

160

VS = 2.7V

140

= 25°C

T

A

120

100

80

60

40

20

0

POWER SUPPL Y REJECTION (dB)

–20

–40

100 1k 10k 100k 1M 10M

–PSRR

+PSRR

FREQUENCY (Hz )

Figure 10. Power Supply Rejection vs. Frequency

00935-010

AD8541/AD8542/AD8544

V

10k

1k

VS = 2.7V
T

= 25°C

A

60

50

VS = 2.7V

= 10kΩ

R

L

= 25°C

T

A

100

10

1

∆ OUTPUT VOLTAGE (mV)

0.1

0.01

0.001 0.01 0.1 1 10 100

SOURCE

SINK

LOAD CURRENT (mA)

Figure 11. Output Voltage to Supply Rail vs. Load Current

3.0

2.5

2.0

1.5

1.0

OUTPUT SWING (V p-p)

0.5

VS = 2.7V

= 2.5V p-p

V

IN

= 2kΩ

R

L

= 25°C

T

A

40

30

20

SMALL SIGNAL OVERSHOOT (%)

10

0

00935-011

10 100 1k 10k

CAPACITANCE (pF)

+OS

–OS

00935-014

Figu re 14. Sm all Signal O vershoot vs. Load Capacitance

60

VS = 2.7V
R

= 2kΩ

L

50

T

= 25°C

A

40

30

20

SMALL SIGNAL OVERSHO OT (%)

10

+OS

–OS

0

1k 10k 100 k 1M 10M

FREQUENCY (Hz)

Figure 12. Closed-Loop Output Voltage Swing vs. Frequency

60

VS = 2.7V
R

=

L

∞

TA = 25°C

50

40

30

20

SMALL SIGNAL OVERSHOOT (%)

10

0

10 100 1k 10k

CAPACITANCE (pF)

+OS

–OS

Figure 13. Small Signal Overshoot vs. Load Capacitance

0

00935-012

10 100 1k 10k

CAPACITANCE (pF)

00935-015

Figure 15. Small Signal Overshoot vs. Load Capacitance

VS = 2.7V
R

= 100kΩ

L

= 300pF

C

L

AV = 1
T

= 25°C

A

1.35

00935-013

50mV 10µs

0935-016

Figure 16. Small Signal Transient Response

Rev. G | Page 8 of 20

AD8541/AD8542/AD8544

VS = 2.7V

= 2kΩ

R

L

= 1

A

V

= 25°C

T

A

1.35V

500mV 10µs

Figure 17. Large Signal Transient Response

VS = 2.7V

= NO LOAD

R

L

= 25°C

T

A

80

60

40

GAIN (dB)

20

0

1k 10k 100k 1M 10M

FREQUENCY (Hz)

Figure 18. Open-Loop Gain and Phase vs. Frequency

160

VS = 5V

140

T

= 25°C

A

120

100

80

60

40

20

0

POWER SUPPLY REJECTI ON RATIO ( dB)

–20

–40

100 1k 10k 100k 1M 10M

–PSRR

+PSRR

FREQUENCY (Hz)

Figure 19. Power Supply Rejection Ratio vs. Frequency

45

90

135

180

00935-017

PHASE SHIFT (Degrees)

00935-018

00935-019

90

VS = 5V
T

= 25°C

80

A

70

60

50

40

30

20

10

COMMON-MODE REJECTION (dB)

0

–10

1k 10k 100k 1M 10M

FREQUENCY (Hz)

Figure 20. Common-Mode Rejection vs. Frequency

5

VS=5V

4

= NO LOAD

R

L

=25°C

T

A

3

2

1

0

–1

–2

INPUT OFFSET VOLTAGE (mV)

–3

–4

–5

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

COMMON-MODE VOL TAGE (V)

Figure 21. Input Offset Voltage vs. Common-Mode Voltage

10k

VS = 5V
T

= 25°C

A

1k

100

10

1

∆ OUTPUT VOL TAGE (mV)

0.1

0.01

0.001 0. 01 0.1 1 10 100

SOURCE

SINK

LOAD CURRENT (mA)

Figure 22. Output Voltage to Supply Rail vs. Load Current

00935-020

00935-040

00935-021

Rev. G | Page 9 of 20

AD8541/AD8542/AD8544

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

OUTPUT SWING (V p-p)

1.0

0.5

0

1k 10k 100k 1M 10M

FREQUENCY (Hz)

VS = 5V
V

= 4.9V p-p

IN

R

= NO LOAD

L

T

= 25°C

A

Figure 23. Closed-Loop Output Voltage Swing vs. Frequency,

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

OUTPUT SWING (V p-p)

1.0

0.5

0

1k 10k 100k 1M 10M

FREQUENCY (Hz)

VS = 5V

= 4.9V p-p

V

IN

= 2kΩ

R

L

= 25°C

T

A

Figure 24. Closed-Loop Output Voltage Swing vs. Frequency

00935-022

00935-023

60

VS = 5V
R

= 2kΩ

L

T

= 25°C

50

A

40

30

20

SMALL SIGNAL OVERSHOOT (%)

10

0

10 100 1k 10k

CAPACITANCE (pF)

+OS

–OS

Figure 26. Small Signal Overshoot vs. Load Capacitance

60

VS = 5V

=

R

L

50

40

30

20

SMALL SIGNAL OVERSHOOT (%)

10

∞

TA = 25°C

+OS

–OS

0

10 100 1k 10k

CAPACITANCE (pF)

Figure 27. Small Signal Overshoot vs. Load Capacitance

00935-025

00935-026

60

VS = 5V

= 10kΩ

R

L

= 25°C

T

50

A

40

+OS

30

20

SMALL SIGNAL OVERSHOOT (%)

10

0

10 100 1k 10k

CAPACITANCE (pF)

–OS

Figure 25. Small Signal Overshoot vs. Load Capacitance

00935-024

Rev. G | Page 10 of 20

2.5V

VS = 5V

= 100kΩ

R

L

CL = 300pF
AV = 1
TA = 25°C

50mV 10µs

Figure 28. Small Signal Transient Response

00935-027

AD8541/AD8542/AD8544

VS = 5V
RL = 2kΩ
AV = 1
TA = 25°C

V

IN

V

OUT

VS = 5V
R

= 10kΩ

L

A

= 1

V

T

= 25°C

A

2.5V

1V 10µs

Figure 29. Large Signal Transient Response

VS = 5V
R

= NO LOAD

L

T

= 25°C

A

80

60

40

GAIN (dB)

20

0

1k 10k 100k 1M 10M

FREQUENCY (Hz)

Figure 30. Open-Loop Gain and Phase vs. Frequency

45

90

135

180

2.5V

00935-028

1V 20µs

00935-030

Figure 31. No Phase Reversal

60

TA = 25°C

50

40

30

20

PHASE SHIFT (Degrees)

10

SUPPLY CURRENT/ AMPLIF IER (µA)

0

00935-029

0123456

SUPPLY VOLTAGE (V)

00935-031

Figure 32. Supply Current per Amplifier vs. Supply Voltage

Rev. G | Page 11 of 20

AD8541/AD8542/AD8544

V

55

50

VS = 5V

45

VS=5V
MARKER SET @ 10kHz
MARKER READING : 37.6nV/ Hz
T

=25°C

A

40

35

30

SUPPLY CURRENT/AM PLIFI ER (µA)

25

20

–55 –35 –15 5 25 45 65 85 105 125 145

TEMPERATURE (°C)

VS = 2.7V

Figure 33. Supply Current per Amplifier vs. Temperature

1000

VS= 2.7V AND 5V

900

A

=1

V

T

= 25°C

A

800

700

600

500

400

IMPEDANCE (Ω)

300

200

100

0

1k 10k 100k 1M 10M 100M

FREQUENCY (Hz)

Figure 34. Closed-Loop Output Impedance vs. Frequency

15nV/DI

0 5 10 15 20 25

00935-032

FREQUENCY (kHz)

00935-034

Figure 35. Voltage Noise

00935-033

Rev. G | Page 12 of 20

AD8541/AD8542/AD8544

THEORY OF OPERATION

NOTES ON THE AD854X AMPLIFIERS

The AD8541/AD8542/AD8544 amplifiers are improved
performance, general-purpose operational amplifiers.
Performance has been improved over previous amplifiers in
several ways, 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.

Higher Output Current

At 5 V single supply, the short-circuit current is typically 60 µA.
Even 1 V from the supply rail, the AD854x amplifiers can provide a
30 mA output current, sourcing, or sinking.

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.

Rev. G | Page 13 of 20

AD8541/AD8542/AD8544

V

V

V

APPLICATIONS

NOTCH FILTER

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.
The components must closely match or notch frequency offset
and drift causes the circuit to no longer attenuate at the ideal
notch frequency. To achieve desired performance, 1% or better
component tolerances or special component screens are usually
required. One method to desensitize the circuit-to-component
mismatch is to increase R2 with respect to R1, which lowers Q.
A lower Q increases attenuation over a wider frequency range
but reduces attenuation at the peak notch frequency.

R

100kΩR100kΩ

V

IN

2.5V

REF

1

f

=

0

2πRC

f

=

0

4 1 –

53.6µF

26.7nF

1

R1

R1 + R2

2C

R/2
50kΩ

C

C

26.7nF

1/2 AD8542

Figure 36. 60 Hz Twin-T Notch Filter, Q = 10

RR

V

IN

2.5V

REF

2C

R/2

C

C

Figure 37. 60 Hz Twin-T Notch Filter, Q = ∞ (Ideal)

3

2

V

IN

7

5.0

7

3

U1

2

5.0

8

1/2 AD8542

U1

1

4

5

U2

6

AD8541

6

4

2.5V

R2

2.5kΩ

R1

97.5kΩ

REF

V

V

OUT

OUT

00935-035

00935-036

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.

R

2.61kΩ

R

2.61kΩ

R

2.61kΩ

R

2.61kΩ

REF

1/4 AD8544

9

U3

10

3

2

2.5V

13

12

REF

8

4

U1

U4

1/4 AD8544

1

11

1/4 AD8544

14

V

OUT

NC

00935-037

V

IN

2.5V

REF

1/4 AD8544

R1

Q ADJUST

200Ω

C1

1µF

C2

1µF

6

7

U2

5

1

f =

2π LC1

L = R2C2

2.5V

Figure 38. FDNR 60 Hz Notch Filter with Output Buffer

COMPARATOR FUNCTION

A comparator function is a common application for a spare op
amp in a quad package. Figure 39 illustrates ¼ of the AD8544 as a
comparator in a standard overload detection application. Unlike
many op amps, the AD854x family can double as comparators
because this op amp family has a rail-to-rail differential input
range, rail-to-rail output, and a great speed vs. power ratio.
R2 is used to introduce hysteresis. The AD854x, when used as
comparators, have 5 µs propagation delay at 5 V and 5 µs
overload recovery time.

R2

DC

1MΩ

1/4 AD8541

V

OUT

00935-038

R1

1kΩ

IN

2.5V

REF

2.5V

Figure 39. AD854x Comparator Application—Overload Detector

Rev. G | Page 14 of 20

AD8541/AD8542/AD8544

PHOTODIODE APPLICATION

The AD854x family has very high impedance with an input bias
current typically around 4 pA. This characteristic allows the
AD854x op amps to be used in photodiode applications and
other applications that require high input impedance. Note that
the AD854x has significant voltage offset that can be removed
by capacitive coupling or software calibration.

Figure 40 illustrates a photodiode or current measurement
application. The feedback resistor is limited to 10 M to avoid
excessive output offset. In addition, a resistor is not needed on
the noninverting input to cancel bias current offset because the
bias current-related output offset is not significant when compared
to the voltage offset contribution. For best performance, follow the
standard high impedance layout techniques, which include the
following:

• 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.

C

100pF

R

10MΩ

OR

D

REF

2.5V

REF

2.5V

Figure 40. High Input Impedance Application—Photodiode Amplifier

V+

7

2

6

3

AD8541

4

V

OUT

00935-039

Rev. G | Page 15 of 20

AD8541/AD8542/AD8544

0

0

OUTLINE DIMENSIONS

3.00

2.90

2.80

.15 MAX
.05 MIN

1.70

1.60

1.50

1.30

1.15

0.90

5

123

4

1.90

BSC

0.50 MAX

0.35 MIN

COMPLIANT TO JEDEC STANDARDS MO-178-AA

0.95 BSC

1.45 MAX

0.95 MIN

3.00

2.80

2.60

SEATING
PLANE

0.20 MAX

0.08 MIN

10°

5°
0°

0.60

BSC

0.55

0.45

0.35

11-01-2010-A

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

PIN 1

1.05

1.00

0.80

0.15

0.05

COPLANARIT Y

0.10

14

1

0.65 BSC

0.30

0.19

COMPLI ANT TO JEDEC STANDARDS MO -153-AB-1

8

6.40
BSC

7

1.20

0.20

MAX

SEATING
PLANE

0.09

8°
0°

0.75

0.60

0.45

061908-A

Figure 42. 14-Lead Thin Shrink Small Outline Package [TSSOP]

(RU-14)

Dimensions shown in millimeters

Rev. G | Page 16 of 20

AD8541/AD8542/AD8544

1.35

1.25

1.15

1.00

0.90

0.70

0.10 MAX

COPLANARITY

0.10

2.20

2.00

1.80

2.40

45

2.10

1.80

312

0.65 BSC

0.22

0.08

0.40

0.10

1.10

0.80

0.30

0.15

COMPLIANT TO JEDEC STANDARDS MO-203-AA

SEATING
PLANE

0.46

0.36

0.26

072809-A

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)

14

1

8

6.20 (0.2441)

5.80 (0.2283)

7

0.25 (0.0098)

0.10 (0.0039)

COPLANARITY

0.10

CONTROL LING DIMENSIO NS ARE IN MILLI METERS; INCH DIMENSIONS
(IN PARENTHESES) ARE ROUNDED-OFF MIL LIME TER EQUIVALENTS F OR
REFERENCE O NLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.

1.27 (0.0500)
BSC

0.51 (0.0201)

0.31 (0.0122)

COMPLI ANT TO JEDEC STANDARDS MS- 012-AB

1.75 (0.0689)

1.35 (0.0531)

SEATING
PLANE

8°
0°

0.25 (0.0098)

0.17 (0.0067)

0.50 (0.0197)

0.25 (0.0098)

1.27 (0.0500)

0.40 (0.0157)

45°

060606-A

Figure 44. 14-Lead Standard Small Outline Package [SOIC_N]

Narrow Body

(R-14)

Dimensions shown in millimeters and (inches)

Rev. G | Page 17 of 20

AD8541/AD8542/AD8544

Y

3.20

3.00

2.80

PIN 1

IDENTIFIER

0.95

0.85

0.75

0.15

0.05

COPLANARITY

3.20

3.00

2.80

8

5

5.15

4.90

4

0.40

0.25

4.65

1.10 MAX

15° MAX

6°
0°

0.23

0.09

1

0.65 BSC

0.10

COMPLIANT TO JEDEC STANDARDS MO-187-AA

Figure 45. 8-Lead Mini Small Outline Package [MSOP]

(RM-8)

Dimensions shown in millimeters

0.80

0.55

0.40

5.00 (0.1968)

4.80 (0.1890)

10-07-2009-B

0.15

0.05

COPLANARIT

0.10

Figure 46. 8-Lead Thin Shrink Small Outline Package [TSSOP]

3.10

3.00

2.90

8

5

4.50

6.40 BSC

4.40

4.30

41

PIN 1

0.65 BSC

1.20
MAX

0.30
SEATING

0.19

PLANE

COMPLIANT TO JEDEC STANDARDS MO-153-AA

0.20

0.09

8°
0°

(RU-8)

Dimensions shown in millimeters

0.75

0.60

0.45

4.00 (0.1574)

3.80 (0.1497)

0.25 (0.0098)

0.10 (0.0040)

COPLANARITY

0.10

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.

85

1

1.27 (0.0500)

SEATING

PLANE

COMPLIANT TO JEDEC STANDARDS MS-012-AA

BSC

6.20 (0.2441)

5.80 (0.2284)

4

1.75 (0.0688)

1.35 (0.0532)

0.51 (0.0201)

0.31 (0.0122)

8°
0°

0.25 (0.0098)

0.17 (0.0067)

0.50 (0.0196)

0.25 (0.0099)

1.27 (0.0500)

0.40 (0.0157)

45°

012407-A

Figure 47. 8-Lead Standard Small Outline Package [SOIC_N]

Narrow Body

(R-8)

Dimensions shown in millimeters and (inches)

Rev. G | Page 18 of 20

AD8541/AD8542/AD8544

ORDERING GUIDE

1, 2

Model

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.

AUTOMOTIVE PRODUCTS

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.

Temperature Range Package Description Package Option Branding

Rev. G | Page 19 of 20

AD8541/AD8542/AD8544

NOTES

©2008–2011 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D00935-0-6/11(G)

Rev. G | Page 20 of 20

Mouser Electronics

Authorized Distributor

Click to View Pricing, Inventory, Delivery & Lifecycle Information:

Analog Devices Inc.:
AD8541AKSZ-R2 AD8541AKSZ-REEL7 AD8541ARTZ-R2 AD8541ARTZ-REEL7 AD8541ARZ AD8542ARMZ

AD8542ARMZ-REEL AD8542ARUZ AD8542ARZ AD8542ARZ-REEL7 AD8544ARUZ AD8544ARZ AD8541ARTZ­REEL AD8541ARZ-REEL AD8541ARZ-REEL7 AD8542ARUZ-REEL AD8542ARZ-REEL AD8544ARUZ-REEL
AD8544ARZ-REEL AD8544ARZ-REEL7 AD8544WARZ-R7 AD8544WARZ-RL