Evaluation Board User Guide
UG-171
Rev. A | Page 3 of 8
EVALUATION BOARD HARDWARE
The evaluation board comes with a cable for connecting to the
printer port of a PC (see Figure 2 for a PC cable diagram and
Figure 4 for a test setup configuration).
The evaluation board schematics are shown in Figure 6 and
POWER SUPPLIES
The board is powered from a single 9 V battery. The power
cupply circuitry allows the user to choose 3 V for the ADF4156
V
DD
and either 3 V or 5 V for the ADF4156 V
P
and VCO supply.
The default settings are 3 V for the ADF4156 V
DD
and 5 V for
the ADF4156 V
P
and the VCO supply.
It is important to note that the ADF4156 V
DD
should never
exceed the ADF4156 V
P
. This can cause damage to the device. If
desired, external power supplies can be used. In this case, the
user must insert SMA connectors as shown in Figure 3 and in
the block diagram (see Figure 1).
LOCAL OSCILLATOR COMPONENTS
The 10 MHz TCXO provides the reference frequency. The on-
chip R divider should be set to 1 so that the PFD frequency is
also 10 MHz. The PLL is made up of the 10 MHz TCXO, the
ADF4156, a passive loop filter (20 kHz bandwidth), and the
V940ME03-LF VCO from Z-Communications, Inc. The output
is available at RF
OUT
through a standard SMA connector.
The on-board loop filter has been designed for a charge pump
current of 0.3125 mA. ADIsimPLL™ can be used to design other
loop filters.
EVAL-ADF41xx
EVAL-ADF421x
9-WAY
FEMALE
D-TYPE
TO
ADF41xx
ADF421x
EVALUATION
BOARD
BLACK-CLK
BROWN-DATA
RED-LE
ORANGE-CE
WHITE-GND
YELLOW
BLUE
PURPLE
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
PC
25-WAY
MALE
D-TYPE
TO PC PRINTER PORT
09173-
002
Figure 2. PC Cable Diagram
09173-
003
Figure 3. Evaluation Board Silkscreen
