
Wideband Synthesizer
with Integrated VCO
Data Sheet
Rev. 0
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Tel: 781.329.4700
Fax: 781.461.3113
FEATURES
Output frequency range: 35 MHz to 4400 MHz
Fractional-N synthesizer and integer-N synthesizer
Low phase noise VCO
Programmable divide-by-1/-2/-4/-8/-16/-32/-64 output
Typical jitter: 0.3 ps rms
Typical EVM at 2.1 GHz: 0.4%
Power supply: 3.0 V to 3.6 V
Logic compatibility: 1.8 V
Programmable dual-modulus prescaler of 4/5 or 8/9
Programmable output power level
RF output mute function
3-wire serial interface
Analog and digital lock detect
Switched bandwidth fast lock mode
Cycle slip reduction
APPLICATIONS
Wireless infrastructure (W-CDMA, TD-SCDMA, WiMAX,
GSM, PCS, DCS, DECT)
Test equipment
Wireless LANs, CATV equipment
Clock generation
GENERAL DESCRIPTION
Th
e ADF4351 allows implementation of fractional-N or integer-N
phase-locked loop (PLL) frequency synthesizers when used with
an external loop filter and external reference frequency.
Th
e ADF4351 has an integrated voltage controlled oscillator (VCO)
with a fundamental output frequency ranging from 2200 MHz to
4400 MHz. In addition, divide-by-1/-2/-4/-8/-16/-32/-64 circuits
allow the user to generate RF output frequencies as low as 35 MHz.
For applications that require isolation, the RF output stage can be
muted. The mute function is both pin- and software-controllable.
An auxiliary RF output is also available, which can be powered
down when not in use.
Control of all on-chip registers is through a simple 3-wire interface.
The device operates with a power supply ranging from 3.0 V to
3.6 V and can be powered down when not in use.
FUNCTIONAL BLOCK DIAGRAM
MUXOUT
CPOUT
LD
SW
VCOM
TEMP
REFIN
CLK
DATA
LE
AVDD
SDVDD
DVDD
VP
AGND
CE
DGND
CPGND
SDGND
AGNDVCO
RSET
VVCO
VTUNE
VREF
RFOUTA+
RFOUTA–
RFOUTB+
RFOUTB–
PHASE
COMPARATOR
FAST LOCK
SWITCH
CHARGE
PUMP
OUTPUT
STAGE
OUTPUT
STAGE
PDBRF
MULTIPLEXER
M
U
LTIP
LE
X
E
R
10-BIT R
COUNTER
÷2
DIVIDER
×2
DOUBLER
FUNCTION
LATCH
DATA REGISTER
INTEGER
VALUE
N COUNTER
FRACTION
VALUE
THIRD-ORDER
FRACTIONAL
INTERPOLATOR
MODULUS
VALUE
MULTIPLEXER
LOCK
DETECT
÷1/2/4/8/16/
32/64
ADF4351
VCO
CORE
09800-
0
01
Figure 1.