Low Distortion
Differential RF/IF Amplifier
AD8351
FEATURES
FUNCTIONAL BLOCK DIAGRAM
–3 dB Bandwidth of 2.2 GHz for AV = 12 dB
Single Resistor Programmable Gain
0 dB ≤ AV ≤ 26 dB
AD8351
VOCM
BIAS CELL
PWUP
RGP1
Differential Interface
VPOS
Low Noise Input Stage 2.7 nV/√Hz @ AV = 10 dB
Low Harmonic Distortion
–79 dBc Second @ 70 MHz
–81 dBc Third @ 70 MHz
OPHI
INHI
OPLO
COMM
OIP3 of 31 dBm @ 70 MHz
INLO
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
RGP2
0
–10
AD8351 WITH 10 dB OF
GAIN DRIVING THE
Power-Down Capability
10-Lead MSOP Package
100nF
25⍀
25⍀
AD6645 (R = 1k⍀)
INHI
L
–20
ANALOG INPUT: 70MHz
ENCODE : 80MHz
AD6645
14-BIT ADC
RG
200⍀
AD8351
AD8351
–30
SNR :
69.1dB
APPLICATIONS
INLO
FUND : –1.1dBFS
HD2 : –78.5dBc
HD3 : –80.7dBc
THD : –75.9dBc
SFDR : 78.2dBc
100nF
–40
Differential ADC Drivers
Single-Ended-to-Differential Conversion
IF Sampling Receivers
RF/IF Gain Blocks
–50
–60
–70
SAW Filter Interfacing
2
3
–80
+
–90
–100
–110
–120
–130
0
5
10
15
20
25
30
35
GENERAL DESCRIPTION
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.
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.
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.
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,
REV. B
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