EVAL-ADF4360-5EBZ1 Analog Devices Inc, EVAL-ADF4360-5EBZ1 Datasheet - Page 20

BOARD EVALUATION FOR ADF4360-5

EVAL-ADF4360-5EBZ1

Manufacturer Part Number
EVAL-ADF4360-5EBZ1
Description
BOARD EVALUATION FOR ADF4360-5
Manufacturer
Analog Devices Inc
Datasheet

Specifications of EVAL-ADF4360-5EBZ1

Main Purpose
Timing, Frequency Synthesizer
Embedded
No
Utilized Ic / Part
ADF4360-5
Primary Attributes
Single Integer-N PLL with VCO
Secondary Attributes
1.3GHz, 200kHz PFD
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
ADF4360-5
APPLICATIONS
DIRECT CONVERSION MODULATOR
Direct conversion architectures are increasingly being used to
implement base station transmitters. Figure 17 shows how ADI
parts can be used to implement such a system.
The circuit block diagram shows the AD9761 TxDAC® being
used with the AD8349. The use of dual integrated DACs, such
as the AD9761 with its specified ±0.02 dB and ±0.004 dB gain
and offset matching characteristics, ensures minimum error
contribution (over temperature) from this portion of the
signal chain.
The local oscillator is implemented using the ADF4360-5. The
low-pass filter was designed using ADIsimPLL for a channel
spacing of 200 kHz and an open-loop bandwidth of 10 kHz.
The LO ports of the AD8349 can be driven differentially from
FREF
MODULATED
DIGITAL
DATA
1nF
IN
10µF
4.7kΩ
1nF
1nF
51Ω
2kΩ
REFIO
FSADJ
14
16
17
18
19
12
13
CPGND
C
REF
CLK
DATA
LE
C
R
1
V
V
N
C
SET
VCO
VCO
6
IN
3
AD9761
TxDAC
DV
8
21
DD
AGND
9
ADF4360-5
AV
V
10 11
DD
2
DD
QOUTB
QOUTA
IOUTA
IOUTB
CE MUXOUT
23
22
DETECT
LOCK
DGND RF
15
20
RF
V
OUT
OUT
TUNE
CP
A
B
Figure 17. Direct Conversion Modulator
24
7
4
5
V
LOW-PASS
LOW-PASS
VCO
47nH
8200pF
FILTER
FILTER
Rev. A | Page 20 of 24
8.2kΩ
4.3kΩ
10nF
47nH
270pF
3.9pF
3.9pF
the complementary RF
ADF4360-5. This gives better performance than a single-ended
LO driver and eliminates the often necessary use of a balun to
convert from a single-ended LO input to the more desirable
differential LO inputs for the AD8349. The typical rms phase
noise (100 Hz to 100 kHz) of the LO in this configuration is 1.09°.
The AD8349 accepts LO drive levels from −10 dBm to 0 dBm.
The optimum LO power can be software programmed on the
ADF4360-5, which allows levels from −13.5 dBm to −4.5 dBm
from each output.
The RF output is designed to drive a 50 Ω load but must be
ac-coupled, as shown in Figure 17. If the I and Q inputs are
driven in quadrature by 2 V p-p signals, the resulting output
power from the modulator is approximately 2 dBm.
5.1nH
5.1nH
QBBP
QBBN
IBBN
IBBP
LOIP
LOIN
OUT
SPLITTER
A and RF
PHASE
VPS1
AD8349
OUT
VPS2
B outputs of the
RF PA
TO
100pF

Related parts for EVAL-ADF4360-5EBZ1