Pentek 6230 Operating Manual page 97

0
ENCODE = 65MSPS
–10
AIN = 15.5MHz @ –29.5dBFS
NO DITHER
–20
–30
–40
–50
–60
–70
–80
–90
–100
–110
–120
–130
0 5 10
FREQUENCY – MHz
Figure 20. 1M FFT Without Dither
100
ENCODE = 65MSPS
90
AIN = 15.5MHz
NO DITHER
80
70
60
50
40
30
20
10
0
–90 –80 –70 –60
ANALOG INPUT POWER LEVEL – dBFS
Figure 21. SFDR Without Dither
95
90 WORST SPUR
85
30.5MHz
80
2.2MHz
75
70
65
–15.0 –10.0 –5.0
ENCODE INPUT POWER – dBm
Figure 22. SNR, Worst Spurious vs. Clamped Encode
Power (See Figure 25)
REV. 0
15 20 25 30
SFDR = 90dB
REFERENCE LINE
–50 –40 –30 –20 –10 0
2.2MHz
ENCODE = 65MSPS
SNR
30.5MHz
15.0
0 5.0 10.0
0
ENCODE = 65MSPS
–10
AIN = 15.5MHz @ –29.5dBFS
DITHER @ –19dBm
–20
–30
–40
–50
–60
–70
–80
–90
–100
–110
–120
–130
0 5 10
Figure 23. 1M FFT with Dither
100
ENCODE = 65MSPS
90
AIN = 15.5MHz
DITHER = –19dBm
80
70
60
50
40
30
20
10
0
–90 –80 –70
ANALOG INPUT POWER LEVEL – dBFS
Figure 24. SFDR with Dither
–11–
AD6644
15 20 25 30
FREQUENCY – MHz
SFDR = 100dB
REFERENCE LINE
SFDR = 90dB
REFERENCE LINE
–60 –50 –40 –30 –20 –10 0