AD9125
Table 18 summarizes the HB2 and HB3 modes.
Table 18. HB2 and HB3 Filter Mode Summary
Mode
fCENTER
fMOD
Input Data
0
DC
None
Real or complex
1
fIN/4
None
Complex
2
fIN/2
None
Complex
3
3fIN/4
None
Complex
4
fIN
fIN
Real or complex
5
5fIN/4
fIN
Complex
6
6fIN/4
fIN
Complex
7
7fIN/4
fIN
Complex
Figure 55 shows the pass-band filter response for HB2. In most
applications, the usable bandwidth of the filter is limited by the
image suppression provided by the stop-band rejection, not by
the pass-band flatness. Table 19 shows the pass-band flatness
and stop-band rejection that the HB2 filter supports at different
bandwidths.
0.02
0
–0.02
–0.04
–0.06
–0.08
–0.10
0
0.04 0.08 0.12 0.16 0.20 0.24 0.28 0.32
NORMALIZED FREQUENCY (× fIN2)
Figure 55. Pass-Band Detail of HB2
Table 19. HB2 Pass-Band Flatness and Stop-Band Rejection
Complex Bandwidth
(% of fIN2)
Pass-Band
Stop-Band
Flatness (dB) Rejection (dB)
50
0.001
85
50.8
0.0012
80
52.8
0.0028
70
56.0
0.0089
60
60
0.0287
50
64.8
0.1877
40
Half-Band Filter 3 (HB3)
HB3 has eight modes of operation that function the same as
HB2. The primary difference between HB2 and HB3 is the filter
bandwidths.
Figure 56 shows the pass-band filter response for HB3. In most
applications, the usable bandwidth of the filter is limited by the
image suppression provided by the stop-band rejection, not by
the pass-band flatness. Table 20 shows the pass-band flatness
and stop-band rejection that the HB3 filter supports at different
bandwidths.
0.02
0
–0.02
–0.04
–0.06
–0.08
–0.10
0
0.04 0.08 0.12 0.16 0.20 0.24 0.28
NORMALIZED FREQUENCY (× fIN3)
Figure 56. Pass-Band Detail of HB3
Table 20. HB3 Pass-Band Flatness and Stop-Band Rejection
Complex Bandwidth
(% of fIN3)
Pass-Band
Flatness (dB)
Stop-Band
Rejection (dB)
40
0.001
85
40.8
0.0014
80
42.4
0.002
70
45.6
0.0093
60
49.8
0.03
50
55.6
0.1
40
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