Evaluation Board User Guide UG-166
Rev. 0 | Page 3 of 8
EVALUATION BOARD HARDWARE
The evaluation board is supplied with a cable for connecting to
the printer port of a PC. The silkscreen and cable diagram for
the evaluation board are shown in Figure 2 and Figure 3, respec-
tively. The board schematics are shown in Figure 5 and Figure 6.
09156-002
Figure 2. Evaluation Board Silkscreen
The board is powered from a single 9 V battery. The power
supply circuitry allows the user to choose either 3 V or 5 V for
the ADF4118 V
DD
and V
P
and for the VCO supply. The default
settings are 3 V for the ADF4118 V
DD
and 5 V for the ADF4118
V
P
and for the VCO supply. It is very important to note that the
ADF4118 V
DD
should never exceed the ADF4118 V
P
. This can
damage the device.
All components necessary for LO generation are included on
board. The 10 MHz TCXO from Vectron provides the necessary
reference input. The PLL is made up of the ADF4118, a passive
loop filter (20 kHz), and the VCO 190-1960T from Vari-L.
The output is available at RF
OUT
through a standard SMA
connector. Alternatively, users can use their own power supplies
and reference input. In this case, insert SMA connectors as
shown on the silkscreen in Figure 2 and the block diagram in
Figure 1.
LOOP COMPONENTS
C1 = 150 pF, C2 = 1.5 nF, C3 = 82 pF.
R1 = 22 kΩ, R1a = 22 kΩ, R2 = 20 kΩ.
1
2
3
4
5
6
7
8
9
9-WAY
FEMALE
D-TYPE
TO
ADF411x
ADF421x
EVALUATION
BOARD
PC
EVAL-ADF421x
EVAL-ADF411x
BLACK-CLK
BROWN-DATA
RED-LE
ORANGE-CE
WHITE-GND
YELLOW
BLUE
PURPLE
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
25-WAY
MALE
D-TYPE
TO PC PRINTER PORT
09156-003
Figure 3. PC Cable Diagram
Loop component values shown in the circuit diagrams (see
Figure 5 and Figure 6) are for a 1.96 GHz RF output, 1 mA
charge pump (CP) current, 200 kHz channel spacing, and
20 kHz loop bandwidth, with a VCO190-1960T.
