Datasheet

AD9251
Rev. A | Page 17 of 36
AD9251-20
AVDD = 1.8 V; DRVDD = 1.8 V, maximum sample rate, 2 V p-p differential input, 1.0 V internal reference; AIN = −1.0 dBFS, DCS
disabled, unless otherwise noted.
0
–15
–30
–45
–60
–75
–90
–105
–120
1.90950k 2.85 3.80 4.75 5.70 6.65 7.60 8.55 9.50
FREQUENCY (MHz)
AMPLITUDE (dBFS)
07938-024
4
3
56
2
20MSPS
9.7MHz @ –1dBFS
SNR = 73.5dBFS (74.5dBFS)
SFDR = 97.2dBc
Figure 26. Single-Tone FFT with f
IN
= 9.7 MHz
0
–15
–30
–45
–60
–75
–90
–105
–120
1.90950k 2.85 3.80 4.75 5.70 6.65 7.60 8.55 9.50
FREQUENCY (MHz)
AMPLITUDE (dBFS)
07938-026
4
3
5
6
2
20MSPS
30.5MHz @ –1dBFS
SNR = 73.2dB (74.2dBFS)
SFDR = 98.1dBc
Figure 27. Single-Tone FFT with f
IN
= 30.5 MHz
120
100
80
60
40
20
0
–100 –90 –80 –70 –60 –50 –40 –30 –20 –10 0
INPUT AMPLITUDE (dBFS)
SNR/SFDR (dBc/dBFS)
07938-058
SFDR (dBFS)
SNR (dBFS)
SFDR (dBc)
SNR (dBc)
Figure 28. SNR/SFDR vs. Input Amplitude (AIN) with f
IN
= 9.7 MHz