UG-802 Datasheet, PDF (4/19 Pages) Analog Devices – EV-ADF5355SD1Z User Guide

UG-802
EVALUATION BOARD HARDWARE
The EV-ADF5355SD1Z requires an SDP-S platform that uses the
EVAL-SDP-CS1Z (SDP-B is not recommended).
The EV-ADF5355SD1Z schematics are shown in Figure 7, Figure 8,
and Figure 9. The silkscreens for the evaluation board are shown in
Figure 10 and Figure 11.
POWER SUPPLIES
The board is powered by a 6 V power supply connected to the
red and black banana connectors. Connect the red connector to
a 6 V power supply and the black connector to ground.
The power supply circuitry allows the user two or three separate
low dropout (LDO) regulators to feed the ADF5355 (using fewer
LDO regulators increases the risk of spur contaminated dc
feeds).
The charge pump and VCO supply pins are powered from a 5 V
ADM7150 high performance, low noise regulator. The remaining
supplies are powered from a 3.3 V ADM7150 high performance,
low noise regulator.
LED1 indicates when the ADF5355 is powered on. Use
Switch S1 to switch the 6 V power to the board on and off.
RF OUTPUT
The EV-ADF5355SD1Z has one pair of SMA output connectors:
RFOUTA+ and RFOUTA− (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).
SMA RFOUTB is a single-ended RF output that operates from
6.8 GHz to 13.6 GHz. If only RFOUTB is used, power off
RFOUTA+ and RFOUTA−. If left on, terminate both RFOUTA+
and RFOUTA− SMA connectors with 50 Ω terminators.
LOOP FILTER
The loop filter schematic is included in the board schematic in
Figure 7. Figure 3 shows the loop filter component placements.
For lowest noise at 100 kHz offset, use the following components
(that are inserted on the evaluation board) with a 0.9 mA charge
pump current:
EV-ADF5355SD1Z User Guide
 C60 = 22 nF, C59 = 0.47 μF, C61 = 10 nF, C73 = 10 pF
 R14 = 220 Ω, R1 = 470 Ω
For lowest rms phase noise, use the following components with
0.9 mA charge pump current:
 C60 = 1.2 nF, C59 = 33 nF, C61 = 390 pF, C73 = 10 pF
 R14 = 1 kΩ, R17 = 3.3 kΩ
R14
R17
RCPOUT
C73
RVTUNE
Figure 3. Loop Filter Placement
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
the REFINA/REFINB SMA connectors. When using an external
reference, remove R12 to disconnect the power rail from the
TCXO.
To use a single-ended REFINx, connect a low noise 122.88 MHz
reference source to SMA REFINB, and connect a 50 Ω terminator
to SMA REFINA. Remove Resistor R27 (100 Ω). To use a differ-
ential REFINx, connect the differential signal to SMA REFINA
and SMA REFINB. The differential REFINA/REFINB SMA
connectors can operate to a 500 MHz input frequency.
In the schematic shown in Figure 7, the REFINA pin of U1
(ADF5355) is connected to SMA REFINB, and the REFINB pin
of U1 (ADF5355) is connected to SMA REFINA. This schematic
matches the evaluation board connections.
DEFAULT CONFIGURATION
All components necessary for local oscillator generation are
inserted on the board. This board is shipped with the ADF5355
synthesizer with an integrated VCO, a differential 122.88 MHz
reference TCXO, and a 5 kHz loop filter (ICP = 0.9 mA).
Rev. B | Page 4 of 19