UG-369
Evaluation Board User Guide
Rev. A | Page 12 of 24
EVALUATION AND TEST
To evaluate and test the performance of the
, use the
following procedure:
1.
If using a different VCO and loop filter than provided on
the board, ensure that a VCO and loop filter are properly
inserted on the board. Use ADIsimPLL to generate the
loop filter component values.
2.
software. Connect the evaluation
board to a PC using the supplied USB cable. Follow the
hardware driver installation procedure that appears.
3.
If the on-board crystal oscillator is used, skip this step. If
an external reference is necessary, connect a reference
signal to the REFIN edge mount connector.
4.
Connect the power supply to the board.
5.
Connect a spectrum analyzer to Connector VCO_I/O.
6.
software.
7.
In the software window, set the VCO center frequency
(Figure 20 shows a screenshot of a spectrum analyzer taken
at a frequency of 1750 MHz, which is in the middle range
of the provided VCO). Set the PFD frequency as defined in
ADIsimPLL, and program the reference frequency to 25
MHz if the on-board TCXO is used or to the frequency
that has been supplied to the REFIN connector. See Figure 21
for the suggested setup.
8.
Measure the output spectrum. Figure 20 shows a
1750 MHz output.
Att
5 dB
A
*
1 AP
CLRWR
Ref
0 dBm
200 kHz/
Center
1.749996795 GHz
Span 2 MHz
*
3DB
RBW 20 kHz
VBW 50 kHz
SWT 20 ms
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
1
Marker 1 [T1 ]
-5.28 dBm
1.749996795 GHz
Date: 14.DEC.2011 16:44:31
1048
2-
020
Figure 20. Spectrum Analyzer Display
1
048
2-
0
21
PC
E
X
T
E
RNAL
DC
SU
PPL
Y
E
X
T
E
RNAL
DC
SU
PPL
Y
TCXO
VCO
LOOP FILTER
LOCK
DETECT
LED
PLL
POWER
LED
USB LED
PLL
USB
POWER
SUPPLIES
SIGNAL
GENERATOR
SPECTRUM
ANALYZER
REFERENCE
(OPTIONAL)
C21
C13
C14
R47
R34
C67
R9
R59
Figure 21. Typical Evaluation Setup