Datasheet

Evaluation Board User Guide UG-096
Rev. A | Page 3 of 12
EVALUATION BOARD HARDWARE
The evaluation board comes with a cable to connect it to the
USB port of a PC. The silkscreen and cable diagram for the
evaluation board are shown in Figure 2. The board schematics
are shown in Figure 9 through Figure 11.
08880-002
Figure 2. Evaluation Board Silkscreen—Top View
The board is powered from a single 9 V battery, or from the
USB supply, by changing the position of Switch SW1. All com-
ponents necessary for LO generation are catered for on-board. A
10 MHz TCXO from Fox Electronics provides the necessary
reference input. Otherwise, an external reference signal can be
connected via J3. The PLL comprises the ADF4360-1BCPZ and
a passive loop filter. The VCO output from RF
OUT
A is available
through the standard SMA Connector J1 and the complemen-
tary RF
OUT
B VCO output is available from J2.
Users may provide their own power supplies using the J4 and J5
connectors, as shown in Figure 2. Hardware power-down using
the CE pin can be controlled by inserting an SMA connector
into J6 and removing R12.
The on-board filter is a third-order, passive, low-pass filter. The
filter contains three capacitors (C13, C14, and C15) plus two
resistors (R10 and R11). The footprint for R10 is located on the
underside of the board. The design parameters for the loop
filter are for a center frequency of 2250 MHz, a PFD frequency
of 200 kHz, and a low-pass filter bandwidth of 10 kHz. To design a
filter for different frequency setups, use the ADIsimPLL simulation
software.
RF OUTPUT STAGES
The output stage of the board contains a tuned load for the
particular frequency of operation. The particular network inserted
in the board is optimized for 2250 MHz operation. This consists
of a 1 nH shunt inductor, a 10 pF series capacitor, and a 1 nH
series inductor. If in doubt, use a 50 Ω resistor instead of the
shunt inductor, a 100 pF bypass capacitor, and a series 0 Ω
resistor. It is important that the same components be placed
on the RF
OUT
A and RF
OUT
B lines. In addition, it is essential
that both outputs be terminated with 50 Ω loads. Otherwise,
the output power is not optimum, and in some cases, the part
may malfunction.