AD9643/AD9613/AD6649/AD6643 User Guide
UG-293
Rev. A | Page 11 of 26
Adjusting the Amplitude of the Input Signal
The next step is to adjust the amplitude of the input signal for
each channel as follows:
1.
Adjust the amplitude of the input signal so that the
fundamental is at the desired level. (Examine the
Fund Power
reading in the left panel of the VisualAnalog
Graph
window.)
See Figure 17.
2.
Repeat this procedure for Channel B if desired.
3.
Click the
Save
disk icon within the
Graph
window to save
the performance plot data as a .csv formatted file. See
Figure 16 for an example.
0
–20
THIRD HARMONIC
SECOND HARMONIC
–40
–60
–80
–100
–120
–140
10
0
20
30
40
50
60
70
80
90 100 110 120
FREQUENCY (MHz)
AM
P
L
IT
UDE
(
d
BF
S
)
250MSPS
90.1MHz @ –1dBFS
SNR = 70.6dB (71.6dBFS)
SFDR = 88dBc
09
94
0-
01
7
Figure 16. Typical FFT,
AD9643
09
940
-0
16
Figure 17. Graph Window of VisualAnalog (
AD9643
)