Analog Devices EV-ADF4356SD1Z, Руководство пользователя

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UG-1062 EV-ADF4356SD1Z User Guide
Rev. A | Page 4 of 13
EVALUATION BOARD HARDWARE
The EV-ADF4356SD1Z requires the SDP-S platform that uses
the EVAL-SDP-CS1Z ( SDP-B is not recommended).
The EV-ADF4356SD1Z schematics are shown in Figure 6, and
Figure 7. The evaluation board silkscreen is shown in Figure 8.
POWER SUPPLIES
The board is powered by a 5.5 V power supply connected to the
red and black banana connectors. Connect the red connector to
a 5.5 V power supply and the black connector to ground. Reversal
of the connections to the red and black banana connectors can
cause catastrophic failure of the HMC1060 low noise regulator.
The
HMC1060 low noise regulator is configured to supply 5 V
for the charge pump and VCO supply pins, and 3.3 V for the
remaining supply pins.
RF OUTPUT
The EV-ADF4356SD1Z has two pairs of SMA output
connectors: /RFOUTA− and /RFOUTB−
(differential outputs). Because they are sensitive to impedance
mismatch, connect the RF outputs to equal load impedances.
If only one port of a differential pair is used, terminate the
complementary port with an equal load terminator (in general,
a 50 Ω terminator).
LOOP FILTER
The loop filter schematic is included in the board schematic in
Figure 6. For lowest rms phase noise, use the following
components (that are inserted on the evaluation board) with a
0.9 mA charge pump current:
• C22 = 120 pF, C29 = 2700 pF, C33 = 22 pF
• R33 = 2.7 kΩ, R34 = 10 kΩ
Narrower loop filter bandwidths have lower spurious signals.
REFERENCE SOURCE
The evaluation board contains a 122.88 MHz differential output
TCXO from Vectron International. If preferred, the user may
supply either a single-ended or differential reference input to
REFINA/REFINB SMA connectors. When using an external
reference, remove R7 to disconnect the power rail to the TCXO.
To use a single-ended REFINx, connect a low noise, 122.88 MHz
reference source to the REFINA SMA connector. Remove Resis-
tor R6 (100 Ω) and insert R10 (50 Ω) and R15 (50 Ω).
To use a differential REFINx, connect the differential signal to
the REFINA and the REFINB SMA connectors. The differential
REFINA/REFINB SMA connectors can operate to a 500 MHz
input frequency.
DEFAULT CONFIGURATION
All components necessary for local oscillator (LO) or clock
generation are inserted on the board. This board is shipped with
the
ADF4356 synthesizer with an integrated VCO, a differential
122.88 MHz reference TCXO, and a 80 kHz loop filter (I
CP
=
0.9 mA).