Analog Devices AD8354 Service Manual

1 MHz to 2.7 GHz

FEATURES

Fixed gain of 20 dB
Operational frequency of 1 MHz to 2.7 GHz
Linear output power up to 4 dBm
Input/output internally matched to 50 Ω
Temperature and power supply stable
Noise figure: 4.2 dB
Power supply: 3 V or 5 V

APPLICATIONS

VCO buffers
General Tx/Rx amplification
Power amplifier predrivers
Low power antenna drivers

GENERAL DESCRIPTION

The AD8354 is a broadband, fixed-gain, linear amplifier that
operates at frequencies from 1 MHz up to 2.7 GHz. It is
intended for use in a wide variety of wireless devices, including
cellular, broadband, CATV, and LMDS/MMDS applications.

By taking advantage of ADI’s high performance, complementary Si
bipolar process, these gain blocks provide excellent stability
over process, temperature, and power supply. This amplifier is
single-ended and internally matched to 50 Ω with a return loss
of greater than 10 dB over the full operating frequency range.

RF Gain Block

AD8354

FUNCTIONAL BLOCK DIAGRAM

BIAS AND VREF

INPT

AD8354

Figure 1.

The noise figure is 4.2 dB at 900 MHz. The reverse isolation
(S

) is −33 dB at 900 MHz.

12

The AD8354 can also operate with a 5 V power supply; in
which case, no external inductor is required. Under these
conditions, the AD8354 delivers 4.88 dBm with 20 dB of gain
at 900 MHz. The dc supply current is 26 mA. At 900 MHz, the
OIP3 is greater than 19 dBm; at 2.7 GHz, the OIP3 is 15 dBm.
The noise figure is 4.4 dB at 900 MHz. The reverse isolation
(S

) is −33 dB.

12

VPOS

VOUT

COM2COM1

02722-001

The AD8354 provides linear output power of nearly 4.3 dBm
with 20 dB of gain at 900 MHz when biased at 3 V and an
external RF choke is connected between the power supply and
the output pin. The dc supply current is 24 mA. At 900 MHz,
the output third-order intercept (OIP3) is greater than 18 dBm;
at 2.7 GHz, the OIP3 is 14 dBm.

Rev. C

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.

The AD8354 is fabricated on ADI’s proprietary, high performance,
25 GHz, Si complementary, bipolar IC process. The AD8354 is
available in a chip scale package that uses an exposed paddle for
excellent thermal impedance and low impedance electrical
connection to ground. It operates over a −40°C to +85°C
temperature range, and an evaluation board is also available.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] © 2005 Analog Devices, Inc. All rights reserved.

AD8354

TABLE OF CONTENTS

Features .............................................................................................. 1

Typical Perf or m an c e Charac t e r istics ..............................................7

Applications....................................................................................... 1

Functional Block Diagram .............................................................. 1

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

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

Specifications..................................................................................... 3

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

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

Pin Configuration and Function Descriptions............................. 6

REVISION HISTORY

12/05—Rev. B to Rev. C

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

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

Moved Figure 39 to Page 15; Renumbered Sequentially........... 15

Changes to Ordering Guide.......................................................... 16

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

Basic Connections...................................................................... 13

Applications..................................................................................... 14

Low Frequency Applications Below 100 MHz........................... 14

Evaluation Board ............................................................................ 15

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

Ordering Guide .......................................................................... 16

8/05—Rev. A to Rev. B

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

Changes to Product Title, Features, and General Description... 1

Changes to Basic Connections Section........................................ 13

Added Low Frequency Applications Below 100 MHz Section. 14

Changes to Ordering Guide.......................................................... 16

Updated Outline Dimensions....................................................... 16

6/02—Rev. 0 to Rev. A

Changes to Ordering Guide............................................................ 4

Replaced TPC 34............................................................................. 10

Updated Outline Dimensions....................................................... 13

2/02—Revision 0: Initial Version

Rev. C | Page 2 of 16

AD8354

SPECIFICATIONS

VS = 3 V, TA = 25°C, 100 nH external inductor between VOUT and VPOS, ZO = 50 Ω, unless otherwise noted.

Table 1.

Parameter Conditions Min Typ Max Unit

OVERALL FUNCTION

Frequency Range 1 2700 MHz

Gain f = 900 MHz 19.5 dB
f = 1.9 GHz 18.6 dB
f = 2.7 GHz 17.1 dB
Delta Gain f = 900 MHz, −40°C ≤ TA ≤ +85°C −0.97 dB
f = 1.9 GHz, −40°C ≤ TA ≤ +85°C −1.05 dB
f = 2.7 GHz, −40°C ≤ TA ≤ +85°C −1.33 dB
Gain Supply Sensitivity VPOS ± 10%, f = 900 MHz 0.54 dB/V
f = 1.9 GHz 0.37 dB/V
f = 2.7 GHz 0.2 dB/V

Reverse Isolation (S12) f = 900 MHz −33.5 dB
f = 1.9 GHz −38 dB
f = 2.7 GHz −32.9 dB

RF INPUT INTERFACE Pin INPT

Input Return Loss f = 900 MHz 24.4 dB
f = 1.9 GHz 23 dB
f = 2.7 GHz 12.7 dB

RF OUTPUT INTERFACE Pin VOUT

Output Compression Point f = 900 MHz, 1 dB compression 4.6 dBm
f = 1.9 GHz 3.7 dBm
f = 2.7 GHz 2.7 dBm
Delta Compression Point f = 900 MHz, −40°C ≤ TA ≤ +85°C 0.7 dB
f = 1.9 GHz, −40°C ≤ TA ≤ +85°C 0.7 dB
f = 2.7 GHz, −40°C ≤ TA ≤ +85°C 0.8 dB
Output Return Loss f = 900 MHz 23.6 dB
f = 1.9 GHz 16.5 dB
f = 2.7 GHz 14.6 dB

DISTORTION/NOISE

Output Third-Order Intercept f = 900 MHz, ∆f = 1 MHz, PIN = −28 dBm 19 dBm
f = 1.9 GHz, ∆f = 1 MHz, PIN = −28 dBm 16 dBm
f = 2.7 GHz, ∆f = 1 MHz, PIN = −28 dBm 14.2 dBm
Output Second-Order Intercept f = 900 MHz, ∆f = 1 MHz, PIN = −28 dBm 29.7 dBm
Noise Figure f = 900 MHz 4.2 dB

f = 1.9 GHz 4.8 dB
f = 2.7 GHz 5.4 dB
POWER INTERFACE Pin VPOS

Supply Voltage 2.7 3 3.3 V
Total Supply Current 16 23 31 mA
Supply Voltage Sensitivity 6.2 mA/V
Temperature Sensitivity −40°C ≤ TA ≤ +85°C 33 μA/°C

Rev. C | Page 3 of 16

AD8354

VS = 5 V, TA = 25°C, no external inductor between VOUT and VPOS, ZO = 50 Ω, unless otherwise noted.

Table 2.

Parameter Conditions Min Typ Max Unit

OVERALL FUNCTION

Frequency Range 1 2700 MHz

Gain f = 900 MHz 19.5 dB
f = 1.9 GHz 18.7 dB
f = 2.7 GHz 17.3 dB
Delta Gain f = 900 MHz, −40°C ≤ TA ≤ +85°C −0.93 dB
f = 1.9 GHz, −40°C ≤ TA ≤ +85°C −0.99 dB
f = 2.7 GHz, −40°C ≤ TA ≤ +85°C −1.21 dB
Gain Supply Sensitivity VPOS ± 10%, f = 900 MHz 0.32 dB/V
f = 1.9 GHz 0.21 dB/V
f = 2.7 GHz 0.08 dB/V
Reverse Isolation (S12) f = 900 MHz −33.5 dB
f = 1.9 GHz −37.6 dB
f = 2.7 GHz −32.9 dB

RF INPUT INTERFACE Pin INPT

Input Return Loss f = 900 MHz 24.4 dB
f = 1.9 GHz 23.9 dB
f = 2.7 GHz 13.5 dB

RF OUTPUT INTERFACE Pin VOUT

Output Compression Point f = 900 MHz 4.8 dBm
f = 1.9 GHz 4.6 dBm
f = 2.7 GHz 3.6 dBm
Delta Compression Point f = 900 MHz, −40°C ≤ TA ≤ +85°C 0.37 dB
f = 1.9 GHz, −40°C ≤ TA ≤ +85°C −0.14 dB
f = 2.7 GHz, −40°C ≤ TA ≤ +85°C −0.05 dB
Output Return Loss f = 900 MHz 23.7 dB
f = 1.9 GHz 22.5 dB
f = 2.7 GHz 17.6 dB

DISTORTION/NOISE

Output Third-Order Intercept f = 900 MHz, ∆f = 50 MHz, PIN = −30 dBm 19.3 dBm
f = 1.9 GHz, ∆f = 50 MHz, PIN = −30 dBm 17.3 dBm
f = 2.7 GHz, ∆f = 50 MHz, PIN = −30 dBm 15.3 dBm
Output Second-Order Intercept f = 900 MHz, ∆f = 1 MHz, PIN = −28 dBm 28.7 dBm
Noise Figure f = 900 MHz 4.4 dB
f = 1.9 GHz 5 dB
f = 2.7 GHz 5.6 dB

POWER INTERFACE Pin VPOS

Supply Voltage 4.5 5 5.5 V
Total Supply Current TA = 27°C 17 25 34 mA
Supply Voltage Sensitivity 4 mA/V
Temperature Sensitivity −40°C ≤ TA ≤ +85°C 28 μA/°C

Rev. C | Page 4 of 16

AD8354

ABSOLUTE MAXIMUM RATINGS

Table 3.

Parameter Rating

Supply Voltage, VPOS 5.5 V
Input Power (re: 50 Ω) 10 dBm

Equivalent Voltage 700 mV rms

Internal Power Dissipation

Paddle Not Soldered 325 mW

Paddle Soldered 812 mW

θ

(Paddle Soldered) 80°C/W

JA

θ

(Paddle Not Soldered) 200°C/W

JA

Maximum Junction Temperature 150°C
Operating Temperature Range −40°C to +85°C
Storage Temperature Range −65°C to +150°C
Lead Temperature (Soldering 60 sec) 240°C

ESD CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on
the human body and test equipment and can discharge without detection. Although this product features
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy
electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance
degradation or loss of functionality.

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. C | Page 5 of 16

AD8354

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

COM1

NC

INPT

COM2

1

AD8354

2

TOP VIEW

3

(Not to Scale)

4

8
7
6
5

COM1
VOUT
VPOS
COM2

NC = NO CONNECT

Figure 2. Pin Configuration

02722-041

Table 4. Pin Function Descriptions

Pin No. Mnemonic Description

1, 8 COM1 Device Common. Connect to low impedance ground.
2 NC No Connection.
3 INPT RF Input Connection. Must be ac-coupled.
4, 5 COM2 Device Common. Connect to low impedance ground.
6 VPOS Positive Supply Voltage.
7 VOUT RF Output Connection. Must be ac-coupled.

Rev. C | Page 6 of 16

AD8354

TYPICAL PERFORMANCE CHARACTERISTICS

90

60

120

90

60

120

150

180

210

Figure 3. S

25

20

15

GAIN (dB)

10

240

270

vs. Frequency, VS = 3 V, TA = 25°C, 100 MHz ≤ f ≤ 3 GHz

11

GAIN AT 3.3V

GAIN AT 3.0V

GAIN AT 2.7V

300

330

30

0

02722-002

150

180

210

Figure 6. S

25

20

15

GAIN (dB)

10

330

240

270

vs. Frequency, VS = 3 V, TA = 25°C, 100 MHz ≤ f ≤ 3 GHz

22

GAIN AT +25°C

300

GAIN AT –40°C

GAIN AT +85°C

30

0

02722-005

5

0

0 3000

500

Figure 4. Gain vs. Frequency, V

0

–5

–10

–15

–20

–25

REVERSE ISOLATION (dB)

–30

–35

–

40

S12 AT 2.7V

0

Figure 5. Reverse Isolation vs. Frequency, V

1000 1500 2000 2500

FREQUENCY (MHz)

= 2.7 V, 3 V, and 3.3 V, TA = 25°C

S

500

1000

1500 2000 2500 3000

FREQUENCY (MHz)

S12 AT 3.3V

= 2.7 V, 3 V, and 3.3 V, TA = 25°C

S

S12 AT 3.0V

02722-003

02722-004

Figure 8. Reverse Isolation vs. Frequency, V

Rev. C | Page 7 of 16

5

0

0

500

1000

FREQUENCY (MHz)

Figure 7. Gain vs. Frequency, V

0

–5

–10

–15

–20

–25

AT –40°C

S

REVERSE ISOLATION (dB)

–30

–35

S

–40

0

12

500

12

AT +85°C

1000

FREQUENCY (MHz)

1500 2000 2500 3000

= 3 V, TA = −40°C, +25°C, and +85°C

S

S

AT +25°C

12

1500 2500 3000

2000

= 3 V, TA = −40°C, +25°C, and +85°C

S

02722-006

02722-007

AD8354

7

6

5

4

(dBm)

3

1dB

P

2

1

0

P1dB (dBm)

P

AT 3.0V

1dB

P

1dB

P

1dB

AT 2.7V

AT 3.3V

6

5

4

(dBm)

3

1dB

P

2

1

P

P

1dB

AT +85°C

1dB

AT +25°C

P

1dB

AT –40°C

–1

0

500 1000 1500 2000 2500 3000

Figure 9. P

1dB

50
45

40
35

30

25

20

PERCENTAGE

15

10

5

0

2.5

2.6

2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8
OUTPUT 1dB COMPRESSION POINT (dBm)

Figure 10. Distribution of P

22

20

FREQUENCY (MHz)

vs. Frequency, VS = 2.7 V, 3 V, and 3.3 V, TA = 25°C

, VS = 3 V, TA = 25°C, f = 2.2 GHz

1dB

OIP3 AT 3.3V

02722-008

02722-009

0

Figure 12. P

500

vs. Frequency, VS = 3 V, TA = −40°C, +25°C, and +85°C

1dB

50
45

40
35

30

25

20

PERCENT

15

10

5

0

14.4

14.6 14.8 15.0 15.2 15.4 15.6 15.8 16.0

Figure 13. Distribution of OIP3, V

22

20

1000 1500 2000 2500 30000

FREQUENCY (MHz)

OIP3 (dBm)

= 3 V, TA = 25°C, f = 2.2 GHz

S

02722-011

02722-012

18

16

OIP3 (dBm)

14

OIP3 AT 3.0V

OIP3 AT 2.7V

12

10

0 2000 2500

500

1000

1500 3000

FREQUENCY (MHz)

Figure 11. OIP3 vs. Frequency, V

= 2.7 V, 3 V, and 3.3 V, TA = 25°C

S

02722-010

Rev. C | Page 8 of 16

18

16

OIP3 (dBm)

OIP3 AT +85°C

14

12

10

0

500

1000

Figure 14. OIP3 vs. Frequency, V

OIP3 AT +25°C

OIP3 AT –40°C

1500 25002000 3000

FREQUENCY (MHz)

= 3 V, TA = −40°C, +25°C, and +85°C

S

02722-013

AD8354

6.0

5.8

5.6

5.4

5.2

5.0

4.8

NOISE FIGURE (dB)

4.6

4.4

4.2

4.0

NF AT 3.0V

NF AT 2.7V

500

NF AT 3.3V

1000

FREQUENCY (MHz)

Figure 15. Noise Figure vs. Frequency, V

40

35

30

25

20

2000 25001500 30000

= 2.7 V, 3 V, and 3.3 V, TA = 25°C

S

02722-014

6.5

6.0

5.5

5.0

500

NF AT +85°C

NF AT +25°C

1000 25002000 30000

FREQUENCY (MHz)

4.5

NOISE FIGURE (dB)

4.0

3.5

3.0

Figure 18. Noise Figure vs. Frequency, V

30

I

25

20

IS AT 3.0V

15

S

NF AT –40°C

1500

= 3 V, TA = −40°C, +25°C, and +85°C

S

AT 3.3V

I

AT 2.7V

S

02722-017

PERCENTAGE

15

10

5

0

4.70

4.75 4.80 4.85 4.90 4.95 5.00 5.05 5.10 5.15 5.20 5.25
NOISE FIGURE (dB)

Figure 16. Distribution of Noise Figure, V

90

120

150

180

210

= 3 V, TA = 25°C, f = 2.2 GHz

S

60

30

330

10

SUPPLY CURRENT (mA)

5

0

–40 –20 0 20 40 60 80 100

–60

02722-015

Figure 19. Supply Current vs. Temperature, V

120

150

0

180

210

TEMPERATURE (°C)

90

= 2.7 V, 3 V, and 3.3 V

S

60

02722-018

30

0

330

Figure 17. S

240

270

vs. Frequency, VS = 5 V, TA = 25°C, 100 MHz ≤ f ≤ 3 GHz

11

300

02722-016

Rev. C | Page 9 of 16

Figure 20. S

240

270

vs. Frequency, VS = 5 V, TA = 25°C, 100 MHz ≤ f ≤ 3 GHz

22

300

02722-019

AD8354

25

GAIN AT 5.5V

20

25

GAIN AT –40°C



20

15

GAIN (dB)

10

GAIN AT 5.0V

GAIN AT 4.5V

5

0

0

500 3000

1000 1500 2000 2500

FREQUENCY (MHz)

Figure 21. Gain vs. Frequency, V

0

–5

–10

–15

–20

–25

REVERSE ISOLATION (dB)

–30

–35

–40

0

S12 AT 4.5V

500

1000

= 4.5 V, 5 V, and 5.5 V, TA = 25°C

S

AT 5.0V

S

12

1500 2000 2500 3000

FREQUENCY (MHz)

Figure 22. Reverse Isolation vs. Frequency, V

7

6

P

1dB

AT 5.5V

AT 5.5V

S

12

= 4.5 V, 5 V, and 5.5 V, TA = 25°C

S

02722-020

02722-021

15

GAIN (dB)

10

5

0

500

0

1000

1500

FREQUENCY (MHz)

Figure 24. Gain vs. Frequency, V

= 5 V, TA = −40°C, +25°C, and +85°C

S

0

–5

–10

–15

–20

AT –40°C

–25

–30

REVERSE ISOLATION (dB)

S

12

–35

–40

0

500

1000

1500 2000 2500 3000

FREQUENCY (MHz)

Figure 25. Reverse Isolation vs. Frequency, V

6

P

AT +85°C

1dB

5

GAIN AT +25°C



GAIN AT +85°C

2000 2500 3000

S

AT +25°C

S

AT +85°C

12

= 5 V, TA = −40°C, +25°C, and +85°C

S

12

02722-023

02722-024

5

4

(dBm)

1dB

3

P

2

1

0

Figure 23. P

P

AT 5.0V

1dB

P

AT 4.5V

1dB

500 1000 1500 2000 2500 30000

FREQUENCY (MHz)

vs. Frequency, VS = 4.5 V, 5 V, and 5.5 V, TA = 25°C

1dB

(dBm)
P

02722-022

Rev. C | Page 10 of 16

P

1dB

4

3

1dB

2

1

0

Figure 26. P

AT –40°C

P

AT +25°C

1dB

500 1000 1500 2000 2500 30000

FREQUENCY (MHz)

vs. Frequency, VS = 5 V, TA = –40°C, +25°C, and +85°C

1dB

02722-025

AD8354

50
45

40
35

35

30

25

30

25

20

PERCENTAGE

15

10

5

0

3.95

4.00

4.05 4.10 4.15 4.20 4.25 4.30 4.35 4.40 4.45 4.50
OUTPUT 1dB COMPRESSION POINT (dBm)

Figure 27. Distribution of P

22

20

18

16

OIP3 (dBm)

14

12

1dB

OIP3 AT 5.5V

OIP3 AT 5.0V

, VS = 5 V, TA = 25°C, f = 2.2 GHz

OIP3 AT 4.5V

02722-026

20

15

PERCENTAGE

10

5

0

16.0

16.1 16.2 16.3 16.4 16.5 16.6 16.7 16.8 16.9 17.0 17.1 17.2

Figure 30. Distribution of OIP3, V

22

20

18

16

OIP3 (dBm)

14

12

OIP3 AT +85°C

OIP3 AT –40°C

OIP3 AT +25°C

OIP3 (dBm)

= 5 V, TA = 25°C, f = 2.2 GHz

S

02722-029

10

Figure 28. OIP3 vs. Frequency, V

7.0

6.5

6.0

5.5

5.0

NOISE FIGURE (dB)

4.5

4.0

500 1000 1500 2000 2500 3000

0

FREQUENCY (MHz)

S

NF AT 5.5V

NF AT 5.0V

500

0

1000

1500 2000 2500 3000

FREQUENCY (MHz)

Figure 29. Noise Figure vs. Frequency, V

= 4.5 V, 5 V, and 5.5 V, TA = 25°C

NF AT 4.5V

= 4.5 V, 5 V, and 5.5 V, TA = 25°C

S

02722-027

NOISE FIGURE (dB)

02722-028

Figure 32. Noise Figure vs. Frequency, V

Rev. C | Page 11 of 16

10

0

1000 1500 2000 2500 3000500

FREQUENCY (MHz)

Figure 31. OIP3 vs. Frequency, V

7.5

7.0

6.5

6.0

5.5

5.0

4.5

4.0

3.5

3.0
0

NF AT +85°C

NF AT +25°C

500

NF AT –40°C

1000

FREQUENCY (MHz)

= 5 V, TA = –40°C, +25°C, and +85°C

S

1500 2000 2500 3000

= 5 V, TA = –40°C, +25°C, and +85°C

S

02722-030

02722-031

AD8354

40

15

20

35

30

25

20

PERCENTAGE

15

10

5

0

4.5

4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 5.5 5.6
NOISE FIGURE (dB)

Figure 33. Distribution of Noise Figure, V

35

30

I

AT 5.5V

S

25

I

AT 4.5V

20

S

IS AT 5.0V

15

10

SUPPLY CURRENT (mA)

5

0

–40 –20 0 20 40 60 80 100

–60

TEMPERATURE (°C)

Figure 34. Supply Current vs. Temperature, V

= 5 V, TA = 25°C, f = 2.2 GHz

S

= 4.5 V, 5 V, and 5.5 V

S

02722-032

02722-033

10

5

(dBm)

0

OUT

P

–5

–10

–15

–30

–25

Figure 35. Output Power and Gain vs. Input Power, V

15

10

5

(dBm)

0

OUT

P

–5

–10

–15

–30 –25 –20 –15 –10 –5 0

Figure 36. Output Power and Gain vs. Input Power, V

–20 –15 –10 –5 0

PIN(dBm)

= 3 V, TA = 25°C, f = 900 MHz

S

PIN (dBm)

= 5 V, TA = 25°C, f = 900 MHz

S

19

18

17

16

15

14

20

19

18

17

16

15

14

GAIN (dB)

02722-034

GAIN (dB)

02722-035

Rev. C | Page 12 of 16

AD8354

THEORY OF OPERATION

The AD8354 is a 2-stage, feedback amplifier employing both
shunt-series and shunt-shunt feedback. The first stage is
degenerated and resistively loaded and provides approximately
10 dB of gain. The second stage is a PNP-NPN Darlington
output stage, which provides another 10 dB of gain. Series­shunt feedback from the emitter of the output transistor sets the
input impedance to 50 Ω over a broad frequency range. Shunt­shunt feedback from the amplifier output to the input of the
Darlington stage helps to set the output impedance to 50 Ω. The
amplifier can be operated from a 3 V supply by adding a choke
inductor from the amplifier output to VPOS. Without this
choke inductor, operation from a 5 V supply is also possible.

BASIC CONNECTIONS

The AD8354 RF gain block is a fixed gain amplifier with single­ended input and output ports whose impedances are nominally
equal to 50 Ω over the frequency range 1 MHz to 2.7 GHz.
Consequently, it can be directly inserted into a 50 Ω system
with no impedance matching circuitry required. The input and
output impedances are sufficiently stable vs. variations in
temperature and supply voltage that no impedance matching
compensation is required. A complete set of scattering
parameters is available at

The input pin (INPT) is connected directly to the base of the
first amplifier stage, which is internally biased to approximately 1 V;
therefore, a dc blocking capacitor should be connected between the
source that drives the AD8354 and the input pin, INPT.

www.analog.com.

It is critical to supply very low inductance ground connections
to the ground pins (Pin 1, Pin 4, Pin 5, and Pin 8) as well as to
the backside exposed paddle. This ensures stable operation.

The AD8354 is designed to operate over a wide supply voltage
range, from 2.7 V to 5.5 V. The output of the part, VOUT, is
taken directly from the collector of the output amplifier stage.
This node is internally biased to approximately 3.2 V when the
supply voltage is 5 V. Consequently, a dc blocking capacitor
should be connected between the output pin, VOUT, and the
load that it drives. The value of this capacitor is not critical, but
it should be 100 pF or larger.

When the supply voltage is 3 V, it is recommended that an
external RF choke be connected between the supply voltage
and the output pin, VOUT. This increases the dc voltage applied
to the collector of the output amplifier stage, which improves
performance of the AD8354 to be very similar to the performance
produced when 5 V is used for the supply voltage. The inductance
of the RF choke should be approximately 100 nH, and care
should be taken to ensure that the lowest series self-resonant
frequency of this choke is well above the maximum frequency
of operation for the AD8354.

Bypass the supply voltage input, VPOS, using a large value
capacitance (approximately 0.47 μF or larger) and a smaller,
high frequency bypass capacitor (approximately 100 pF)
physically located close to the VPOS pin.

The recommended connections and components are shown in
Figure 40.

Rev. C | Page 13 of 16

AD8354

2

2

2

2

APPLICATIONS

The AD8354 RF gain block can be used as a general-purpose,
fixed gain amplifier in a wide variety of applications, such as a
driver for a transmitter power amplifier (see

Figure 37). Its
excellent reverse isolation also makes this amplifier suitable for
use as a local oscillator buffer amplifier that would drive the
local oscillator port of an upconverter or downconverter mixer
(see

Figure 38).

AD8354

HIGH POWER
AMPLIFIER

02722-036

Figure 37. AD8354 as a Driver Amplifier

MIXER

AD8354

LOCAL OSCILLATOR

02722-037

Figure 38. AD8354 as a LO Driver Amplifier

LOW FREQUENCY APPLICATIONS BELOW 100 MHz

The AD8354 RF gain block can be used below 100 MHz. To
accomplish this, the series dc blocking capacitors, C1 and C2,
need to be changed to a higher value that is appropriate for the
desired frequency. C1 and C2 were changed to 0.1 μF to accomplish
the sweeps in

19.5

19.0

18.5

18.0

17.5

17.0

16.5

Figure 39.

1.5
dB-S21

1.0

0.5

0.0

CH 1: START 300.000kHz STOP 100.000MHz

Figure 39. Low Frequency Application from

300 kHz to 100 MHz at 5 V VPOS, −12 dBm Input Power

Mkr 1: 19.40dB97.638034MHz

1

02722-042

Rev. C | Page 14 of 16

AD8354

T

EVALUATION BOARD

Figure 40 shows the schematic of the AD8354 evaluation board.
Note that L1 is shown as an optional component that is used to
obtain maximum gain only when V
by a single supply in the 2.7 V to 5.5 V range. The power supply
is decoupled by a 0.47 μF and a 100 pF capacitor.

AD8354

COM1

1

NC

2

C1

1000pF

INPU

INPT

3

4

NC = NO CONNECT

Figure 40. Evaluation Board Schematic

Table 5. Evaluation Board Configuration Options

Component Function

C1, C2 AC coupling capacitors.

C3 High frequency bypass capacitor.

C4 Low frequency bypass capacitor.

L1

Optional RF choke, used to increase
current through output stage when

= 3 V. Not recommended for use

V

P

when V

= 5 V.

P

= 3 V. The board is powered

P

COM1

8

VOUT

VPOS

COM2COM2

7

6

5

1000pF

L1

C3
100pFC40.47μF

C2

OUTPUT

Default
Value

1000 pF,
0603

100 pF,
0603

0.47 μF,
0603

100 nH,
0603

02722-039

Figure 41. Silkscreen Top

02722-038

02722-040

Figure 42. Component Side

Rev. C | Page 15 of 16

AD8354

R

OUTLINE DIMENSIONS

1.89

1.74

1.59

58

BOTTOM VIEW

EXPOSED PAD

4 1

*

0.55

0.40

0.30

0.15

0.10

0.05

0.25

0.20

0.15

PIN 1

INDICATO

1.00

0.85

0.80

SEATING

1.95

1.75

1.55

PLANE

3.25

3.00

2.75

0.60

0.45

0.30

0.50 BSC

0.05 MAX

0.02 NOM

12° MAX

TOP VIEW

2.95

2.75

2.55

0.30

0.23

0.18

2.25

2.00

1.75

0.80 MAX

0.65 TYP

0.20 REF

Figure 43. 8-Lead Lead Frame Chip Scale Package [LFCSP_VD]

2 mm × 3 mm Body, Very Thin, Dual Lead

CP-8-1

Dimensions shown in millimeters

ORDERING GUIDE

Model Temperature Range Package Description Package Option Branding

AD8354ACP-R2 −40°C to +85°C 8-Lead LFCSP_VD, 7" Tape and Reel CP-8-1 JC
AD8354ACP-REEL7 −40°C to +85°C 8-Lead LFCSP_VD, 7" Tape and Reel CP-8-1 JC
AD8354ACPZ-REEL71 −40°C to +85°C 8-Lead LFCSP_VD, 7" Tape and Reel CP-8-1 0G
AD8354-EVAL Evaluation Board

1

Z = Pb-free part.

© 2005 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
C02722–0–12/05(C)

T

Rev. C | Page 16 of 16

TTT