3.0 Applications Information (Continued)
e b
e
R
OLPA 1A
to 1 by choosing R such that: R
H
The resistors for the second section are found in a similar
fashion:
4A
4A
e
R
1A
20k. If the 50/100/CL pin is connected to mid-sup-
ply for nominal 100:1 clock-to-center-frequency ratio, we
find R by:
e
e
R
20k
1B
4B
2A
e
R
R
1B
20k
2
2
(529)
f
0A
2
2
(993)
4
10
f
e
e
e
c
c
e
2
R
R
2
5.6k and
4
0B
/100)
2A
3A
4A
e
e
e
19.7k
2
2
R
R
4B
20k
(f
/100)
(1000)
3
2B
CLK
2
(f
CLK
(1000)
e
R
2A 4A
c
0.785 5.6 10
c
c
e
10 8.3k
R
Q
R
2
0
0
A
4
4
e
e
R R
2B 4B
c
3.559 1.97 10
c
c
e
10 70.6k
R
3B
Q
B
2
0
0
g
The complete circuit is shown in Figure 16 for split 5V
power supplies. Supply bypass capacitors are highly recom-
mended.
TL/H/10399–25
FIGURE 16. Fourth-Order Chebyshev Low-Pass Filter from Example in 3.1.
g
b
5V Power Supply. 0V–5V TTL or 5V 5V CMOS Logic Levels.
g
TL/H/10399–26
FIGURE 17. Fourth-Order Chebyshev Low-Pass Filter from Example in 3.1.
a
Single 10V Power Supply. 0V–5V TTL Logic Levels. Input Signals
Should be Referred to Half-Supply or Applied through a Coupling Capacitor.
14
NSC [ National Semiconductor ]
