ADF4218 Datasheet, PDF (1/20 Pages) Analog Devices – Dual RF PLL Frequency Synthesizers

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Dual RF PLL Frequency Synthesizers
ADF4216/ADF4217/ADF4218
FEATURES
ADF4216: 550 MHz/1.2 GHz
ADF4217: 550 MHz/2.0 GHz
ADF4218: 550 MHz/2.5 GHz
2.7 V to 5.5 V Power Supply
Selectable Charge Pump Currents
Selectable Dual Modulus Prescaler
IF: 8/9 or 16/17
RF: 32/33 or 64/65
3-Wire Serial Interface
Power-Down Mode
APPLICATIONS
Wireless Handsets (GSM, PCS, DCS, CDMA, WCDMA)
Base Stations for Wireless Radio (GSM, PCS, DCS,
CDMA, WCDMA)
Wireless LANS
Communications Test Equipment
CATV Equipment
GENERAL DESCRIPTION
The ADF4216/ADF4217/ADF4218 are dual frequency synthe-
sizers that can be used to implement local oscillators (LOs) in
the upconversion and downconversion sections of wireless
receivers and transmitters. They can provide the LO for both
the RF and IF sections. They consist of a low-noise digital PFD
(Phase Frequency Detector), a precision charge pump, a pro-
grammable reference divider, programmable A and B counters,
and a dual-modulus prescaler (P/P+1). The A (6-bit) and B
(11-bit) counters, in conjunction with the dual modulus prescaler
(P/P+1), implement an N divider (N = BP + A). In addition,
the 14-bit reference counter (R Counter), allows selectable
REFIN frequencies at the PFD input. A complete PLL (Phase-
Locked Loop) can be implemented if the synthesizers are
used with an external loop filter and VCOs (Voltage Con-
trolled Oscillators).
Control of all the on-chip registers is via a simple 3-wire interface.
The devices operate with a power supply ranging from 2.7 V
to 5.5 V and can be powered down when not in use.
FUNCTIONAL BLOCK DIAGRAM
V_DD1 V_DD2 V_P1 V_P2
IF_INA
IF_INB
N = BP + A
IF
PRESCALER
REF_IN
CLOCK
DATA
LE
OSCILLATOR
22-BIT
DATA
REGISTER
SDOUT
RF_INA
RF_INB
N = BP + A
RF
PRESCALER
11-BIT IF
B-COUNTER
6-BIT IF
A-COUNTER
14-BIT IF
R-COUNTER
ADF4216/ADF4217/ADF4218
PHASE
COMPARATOR
CHARGE
PUMP
IF
LOCK
DETECT
OUTPUT
MUX
CP_IF
MUXOUT
14-BIT IF
R-COUNTER
11-BIT RF
B-COUNTER
6-BIT RF
A-COUNTER
RF
LOCK
DETECT
PHASE
COMPARATOR
CHARGE
PUMP
CP_RF
REV. 0
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which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
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