Datasheet
UG-405 Evaluation Board User Guide
Rev. 0 | Page 4 of 20
EVALUATION BOARD HARDWARE
The evaluation board comes with a USB cable to connect to the
USB port of a PC. The evaluation board silkscreen is shown in
Figure 3. The EV-ADF41020EB1Z schematics are shown in
Figure 8, Figure 9, Figure 10, and Figure 11.
POWER SUPPLIES
The board is powered via two external supplies, 5.5 V and 15 V,
and connected as described in the Quick Start Guide Section.
INPUT SIGNALS
The 100 MHz TCXO provides the necessary reference signal.
An external REF
IN
may be used if desired. A low noise, high
slew rate reference source is best for achieving the stated
performance of the ADF41020.
OUTPUT SIGNALS
The VCO output is available at EXT_VCOOUT through a
standard SMA connector.
LOOP FILTER
An active loop filter using standard feedback is inserted
between the charge pump output and the VCO input. Figure 2
shows the ADIsimPLL loop filter configuration. Table 1 shows
how the ADIsimPLL loop filter component descriptors are
related to the evaluation board descriptors in Figure 8, Figure 9,
Figure 10, and Figure 11. Figure 3 shows the loop filter
component placements.
The design parameters for the loop filter are for a center
frequency of 12,500 MHz, a PFD frequency of 2.5 MHz, and
an active loop filter bandwidth of 30 kHz. To design a filter for
different frequency setups, use the ADIsimPLL simulation
software to generate filter component values and evaluate
results.
Table 1. Filter Components
ADIsimPLL Evaluation Board
C1 C21
R1 R59
C2 C19
R2 R10
C3 C18
R3 R12
C4 C20
C3
C2
R2
R3
R1
C1
C4
10675-002
V
R
Figure 2. ADIsimPLL Filter
DEFAULT OPERATION
All components necessary for LO generation are inserted
on the board. The board is shipped with the ADF41020
synthesizer, an active loop filter, and the VCO.
10675-017
Figure 3. Evaluation Board Silkscreen