Datasheet

AD9255 Data Sheet
Rev. C | Page 20 of 44
0
–20
–40
–60
–80
–100
–120
–140
0 102030 605040
AMPLITUDE (dBFS)
FREQUENCY (MHz)
SECOND
HARMONIC
THIRD
HARMONIC
125MSPS
70.1MHz @ –6dBFS
SNR = 72.6dB (78.6dBFS)
SFDR = 99.7dBc
08505-136
Figure 36. AD9255-125 Single-Tone FFT with f
IN
= 70.1 MHz at −6 dBFS with
Dither Enabled
0
–135
–120
–105
–90
–75
–60
–45
–30
–15
6054484236302418126
AMPLITUDE (dBFS)
FREQUENCY (MHz)
+
2
5
3
4
6
08505-137
125MSPS
70.1MHz @ –23dBFS
SNR = 56.4dBc (79.4dBFS)
SFDR = 75.8dBc
Figure 37. AD9255-125 Single-Tone FFT with f
IN
= 70.1 MHz at −23 dBFS with
Dither Disabled, 1M Sample
0
–135
–120
–105
–90
–75
–60
–45
–30
–15
6054484236302418126
AMPLITUDE (dBFS)
FREQUENCY (MHz)
+
2
5
3
4
6
08505-138
125MSPS
70.1MHz @ –23dBFS
SNR = 55.9dBc (78.9dBFS)
SFDR = 86.6dBc
Figure 38. AD9255-125 Single-Tone FFT with f
IN
= 70.1 MHz at −23 dBFS with
Dither Enabled, 1M Sample
120
100
80
60
40
20
0
–100 –80–90 –70 –60 –50 –40 –30 –20 –10 0
SNR/SFDR (dBc AND dBFS)
INPUT AMPLITUDE (dBFS)
SNR (dBFS)
SFDR (dBc)
SNR (dBc)
SFDR (dBFS)
08505-139
Figure 39. AD9255-125 Single-Tone SNR/SFDR vs. Input Amplitude (A
IN
) with
f
IN
= 2.4 MHz
120
100
80
60
40
20
0
–100 –80–90 –70 –60 –50 –40 –30 –20 –10 0
SNR/SFDR (dBc AND dBFS)
INPUT AMPLITUDE (dBFS)
SNR (dBFS)
SFDR (dBc)
SNR (dBc)
SFDR (dBFS)
08505-140
Figure 40. AD9255-125 Single-Tone SNR/SFDR vs. Input Amplitude (A
IN
) with
f
IN
= 98.12 MHz
120
110
100
90
80
70
–100 –80–90 –70 –60 –50 –40 –30 –20 –10 0
SNR/SFDR (dBFS)
INPUT AMPLITUDE (dBFS)
SFDRFS (DITHER ON)
SFDRFS (DITHER OFF)
SNRFS (DITHER ON)
SNRFS (DITHER OFF)
08505-141
Figure 41. AD9255-125 Single-Tone SNR/SFDR vs. Input Amplitude (A
IN
) with
f
IN
= 30 MHz With and Without Dither Enabled