AD9042
0
0
POWER RELATIVE TO ADC FULL SCALE – dB
POWER RELATIVE TO ADC FULL SCALE – dB
–20
ENCODE = 41 MSPS
AIN = 19.5MHz @ –29 dBFS
NO DITHER
–20
ENCODE = 41 MSPS
AIN = 19.5MHz @ –29 dBFS
DITHER = –32.5dBm
–40
–40
–60
–60
–80
2
4
6
8
8
7
5
3
–80
2
4
6
8
8
7
5
3
–100
–100
–120
dc
4.1
8.2
12.3
FREQUENCY – MHz
16.4
20.5
–120
dc
4.1
8.2
12.3
FREQUENCY – MHz
16.4
20.5
Figure 20. 4K FFT without Dither
Figure 23. 4K FFT with Dither
100
90
WORST CASE SPURIOUS – dBc
WORST CASE SPURIOUS – dBc
100
ENCODE = 41 MSPS
AIN = 19.5MHz
NO DITHER
90
80
70
60
50
40
30
20
10
0
0
–80
–70
SFDR = 80dB
REFERENCE LINE
–60
–50
–40
–30
–20
–10
ANALOG INPUT POWER LEVEL – dBFS
0
ENCODE = 41 MSPS
AIN = 19.5MHz
DITHER = –32.5dBm
80
70
60
50
40
30
20
10
0
–80
SFDR = 80dB
REFERENCE LINE
–70
–60
–50
–40
–30
–20
–10
ANALOG INPUT POWER LEVEL – dBFS
Figure 21. SFDR without Dither
Figure 24. SFDR with Dither
0
POWER RELATIVE TO ADC FULL SCALE – dB
POWER RELATIVE TO ADC FULL SCALE – dB
0
ENCODE = 41 MSPS
AIN = 2.5MHz @ –26 dBFS
NO DITHER
ENCODE = 41 MSPS
AIN = 2.5MHz@–26dBFS
DITHER = –32.5dBm
–20
–20
–40
–40
–60
–60
–80
–80
–100
–100
–120
dc
4.1
8.2
12.3
FREQUENCY – MHz
16.4
20.5
–120
dc
4.1
8.2
12.3
FREQUENCY – MHz
16.4
20.5
Figure 22. 128K FFT without Dither
Figure 25. 128K FFT with Dither
–10–
REV. A
AD [ ANALOG DEVICES ]
