Digital Signal Processing Reference
In-Depth Information
H(j
Ω
)
1
Ω,,,
rad./sec.
−Ω
c
0
Ω
c
(a)
H(e
j
ω
)
1
ω,
rad./sec.
−ω
c
0
ω
c
(b)
FIGURE 5.1
(a) Analog frequency response of ideal low-pass filter; (b) digital frequency response of ideal
low-pass filter.
shown in
Figure 5.2
. The component resistor and capacitor values are
designed using Equation 5.1.
3
2
1
c
Cutoff frequency
fHz
()
==
(5.1)
c
ππ
2
RC
where the resistor value is in ohms and capacitor value is in Farads.
However, the same filter response, as shown in Figure 5.1a can also be
realized using a
digital filter,
as shown by the system block diagram in
