AD6644
100
95
WORST OTHER SPUR
90
ENCODE = 65MSPS
AIN = –1dBFS
85
80
75
70
HARMONICS (2nd, 3rd)
65
60
55
0 10 20 30 40 50 60 70 80 90 100
ANALOG FREQUENCY – MHz
Figure 14. Harmonics vs. Analog Frequency (IF)
120
110
100
90
80
70
60
50
40
30
20
10
0
–80
ENCODE = 65MSPS
AIN = 15.5MHz
dBFS
dBc
SFDR = 90dB
REFERENCE LINE
–70 –60 –50 –40 –30 –20 –10 0
ANALOG INPUT POWER LEVEL – dBFS
Figure 15. Single Tone SFDR
0
ENCODE = 65MSPS
–10
AIN = 19MHz,
–20
19.5MHz @ –7dBFS
NO DITHER
–30
–40
–50
–60
–70
–80
–90
–100
–110
–120
–130
0
5
10
15
20
25
30
FREQUENCY – MHz
Figure 16. Two Tones at 19 MHz and 19.5 MHz
0
–10
ENCODE = 65MSPS
–20
AIN = 15MHz,
15.5MHz @ –7dBFS
–30
NO DITHER
–40
–50
–60
–70
–80
–90
–100
–110
–120
–130
0
5
10
15
20
25
30
FREQUENCY – MHz
Figure 17. Two Tones at 15 MHz and 15.5 MHz
110
dBFS
100
90 ENCODE = 65MSPS
F1 = 15MHz
80 F2 = 15.5MHz
dBc
70
60
SFDR = 90dB
50
REFERENCE LINE
40
30
20
10
0
–77 –67 –57 –47 –37 –27 –17
–7
INPUT POWER LEVEL – (F1 = F2) dBFS
Figure 18. Two-Tone SFDR
100
AIN = 2.2MHz @ –1dBFS
95
WORST SPUR
90
85
80
75
SNR
70
65
60
0 10 20 30 40 50 60 70 80 90
ENCODE FREQUENCY – MHz
Figure 19. SNR, Worst Spurious vs. Encode
–10–
REV. 0