ISL5216_07 Datasheet, PDF (55/65 Pages) Intersil Corporation – Four-Channel Programmable Digital Downconverter

ISL5216
ROMd FIR Filters - Response Curves
0.0
-1.0
-2.0
-3.0
-4.0
-5.0
-6.0
0.0
N=1
N=5
N=4
N=2
N=3
0.1
0.2
0.3
0.4
0.5
f_S/R
FIGURE 13. CIC PASSBAND ROLLOFF (N = # OF STAGES,
R = DECIMATION FACTOR, f_S/R = 1 is CIC
OUTPUT RATE)
0
N=1
-20
-40
-60
-80
N=2
-100
-120
N=3
N=4
N=5
-140
0.00
0.10
0.20
0.30
0.40
0.50
f_S/R
FIGURE 14. CIC FIRST ALIAS LEVEL (N = # OF STAGES,
R = DECIMATION FACTOR, f_S/R = 1 is CIC
OUTPUT RATE)
0
-20
-40
-60
-80
-100
-120
-140
0.0
0.5
1.0
1.5
2.0
2.5
3.0
f_S/R
FIGURE 15. 5TH ORDER (N = 5) CIC RESPONSE
(R = DECIMATION FACTOR, f_S/R = 1 is CIC
OUTPUT RATE)
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
-120
0
0.125
HBF2
HBF1
HBF5
HBF4
HBF3
0.25
0.375
0.5
f_S
NOTE: HBF4 not included in the ROMd Fir Filter Coefficient memory.
See Note 26 of Table 52.
FIGURE 16. ROMd HALFBAND FILTER FREQUENCY
RESPONSE
0
-10
-20
-30
HBF3
-40
HBF2
-50 HBF1
-60
-70
HBF5
-80
HBF4
-90
-100
-110
-120
0
0.0625
0.125
0.1875
0.25
f_S
NOTE: HBF4 not included in the ROMd Fir Filter Coefficient memory. See Note 26 of Table 52.
FIGURE 17. ROMd HALFBAND FILTER ALIAS FREQUENCY RESPONSE
55
FN6013.3
July 13, 2007