AD8351

Low Distortion

Differential RF/IF Amplifier

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© 2004 Analog Devices, Inc. All rights reserved.

FEATURES

Single Resistor Programmable Gain

0 dB

Differential Interface

Low Noise Input Stage 2.7 nV/

Low Harmonic Distortion

–79 dBc Second @ 70 MHz

–81 dBc Third @ 70 MHz

OIP3 of 31 dBm @ 70 MHz

Single-Supply Operation: 3 V to 5.5 V

Low Power Dissipation: 28 mA @ 5 V

Adjustable Output Common-Mode Voltage

Fast Settling and Overdrive Recovery

Slew Rate of 13,000 V/ s

Power-Down Capability

10-Lead MSOP Package

APPLICATIONS

Differential ADC Drivers

Single-Ended-to-Differential Conversion

IF Sampling Receivers

RF/IF Gain Blocks

SAW Filter Interfacing

FUNCTIONAL BLOCK DIAGRAM

VOCM

VPOS

OPHI

OPLO

COMM

PWUP

RGP1

INHI

INLO

RGP2

AD8351

BIAS CELL

GENERAL DESCRIPTION

The AD8351 is a low cost differential amplifier useful in RF and

IF applications up to 2.2 GHz. The voltage gain can be set from

unity to 26 dB using a single external gain resistor. The AD8351

provides a nominal 150

Ω differential output impedance. The

excellent distortion performance and low noise characteristics of

this device allow for a wide range of applications.

The AD8351 is designed to satisfy the demanding performance

requirements of communications transceiver applications. The

device can be used as a general-purpose gain block, an ADC driver,

05

10

15

20

25

30

35

2

3

+

RG

AD8351

100nF

100nF 25

25

AD6645

14-BIT ADC

INHI

INLO

200

AD8351

AD8351 WITH 10 dB OF

GAIN DRIVING THE

AD6645 (RL = 1k )

ANALOG INPUT: 70MHz

ENCODE : 80MHz

SNR :

69.1dB

FUND : –1.1dBFS

HD2 :

–78.5dBc

HD3 :

–80.7dBc

THD :

–75.9dBc

SFDR :

78.2dBc

0

–10

–20

–40

–30

–50

–60

–70

–80

–90

–120

–100

–130

–110

and a high speed data interface driver, among other functions. The

AD8351 can also be used as a single-ended-to-differential

amplifier with similar distortion products as in the differential

configuration. The exceptionally good distortion performance

makes the AD8351 an ideal solution for 12-bit and 14-bit IF

sampling receiver designs.

Fabricated in ADI’s high speed XFCB process, the AD8351

has high bandwidth that provides high frequency performance

and low distortion. The quiescent current of the AD8351 is 28 mA

typically. The AD8351 amplifier comes in a compact 10-lead

MSOP package and will operate over the temperature range

of –40

°C to +85°C.

REV. B