tda7333 STMicroelectronics, tda7333 Datasheet - Page 6

• Manufacturer Part Number: tda7333
• Description: Rds/rbds Processor
• Manufacturer: STMicroelectronics

TDA7333
The architecture is a very economical implementation because digital multipliers are not required. It is imple-
mented by cascading 4 integrators operating at full sampling rate (XTI/2) followed by 4 differentiators operating
at the reduced sampling rate (XTI/2/16). Also wrap around logic is allowed and the internal overflow will not af-
fect the output signal as long as a minimum required bit width is maintained.
The transfer function of this Sinc4/16 filter is:
and its frequency response is:
Figure 4. Transfer function of a 4th order Sinc Filter, decimation factor is 16.
6/21
100
10
20
30
40
50
60
70
80
90
0
0
0.2
0.4
H e j
0.6
H z
with K = 4, M = 16
0.8
Sinc4/16 Transfer Function
=
=
=
Frequency [Hz]
with
---- -
M
---- -
M
1
1
2
1
1 z M
--------------------
-----------------------
sin
1 z 1
sin
–
---- -
fs
–
f
M
-------- -
–
1.2
–
--- -
2
2
K
K
1.4
1.6
1.8
2
x 10
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