AD9200
Figures 35–38 combine the dual-tone SFDR as well as single
tone SFDR and SNR performance at IF frequencies of 45 MHz,
70 MHz, 85 MHz and 135 MHz. Note, the SFDR vs. ampli-
tude data is referenced to dBFS while the single tone SNR data
is referenced to dBc. The performance characteristics in these
figures are representative of the AD9200 without the AD8009.
The AD9200 was operated in the differential mode (via trans-
former) with a 1 V span at 20 MSPS. The analog supply
(AVDD) and the digital supply (DRVDD) were set to +5 V and
3.3 V, respectively.
Although not presented, data was also taken with the insertion
of an AD8009 gain stage of 32 dB in the signal path. No
degradation in two-tone SFDR vs. amplitude was noted at an
IF of 45 MHz, 70 MHz and 85 MHz. However, at 135 MHz,
the AD8009 became the limiting factor in the distortion perfor-
mance until the two input tones were decreased to –15 dBFS
from their full-scale level of –6.5 dBFS. Note: the SNR perfor-
mance in each case degraded by approximately 0.5 dB due to
the AD8009’s in-band noise contribution.
90
90
SINGLE TONE SFDR
80
80
DUAL TONE SFDR
70
70
SINGLE TONE SFDR
DUAL TONE SFDR
60
60
50
40
50
40
30
30
SNR
SNR
CLK = 20MSPS
SINGLE TONE – 45.52MHz
DUAL TONE– F = 44.49MHz
1
20
10
0
20
10
0
CLK = 20MSPS
SINGLE TONE – 85.52MHz
DUAL TONE– F = 84.49MHz
1
– F = 45.52MHz
2
– F = 85.52MHz
2
–60
–50
–40
–30
–20
–10
0
–60
–50
–40
–30
–20
–10
0
INPUT POWER LEVEL – dBFS
INPUT POWER LEVEL – dBFS
Figure 35. SNR/SFDR for IF @ 45 MHz
Figure 37. SNR/SFDR for IF @ 85 MHz
90
90
SINGLE TONE SFDR
80
80
70
60
DUAL TONE SFDR
SINGLE TONE SFDR
70
DUAL TONE SFDR
60
50
40
50
40
30
30
20
10
SNR
SNR
20
10
0
CLK = 20MSPS
SINGLE TONE – 135.52MHz
DUAL TONE – F = 134.44MHz
CLK = 21.538MSPS
SINGLE TONE – 70.55MHz
1
DUAL TONE– F = 69.50MHz
1
– F = 135.52MHz
2
– F = 70.55MHz
2
0
–60
–50
–40
–30
–20
–10
0
–60
–50
–40
–30
–20
–10
0
INPUT POWER LEVEL – dBFS
INPUT POWER LEVEL – dBFS
Figure 36. SNR/SFDR for IF @ 70 MHz
Figure 38. SNR/SFDR for IF @ 135 MHz
REV. E
–17–
ADI [ ADI ]
