Datasheet
11
LTC1065
1065fb
U
S
A
O
PP
L
IC
AT
I
WU
U
I FOR ATIO
An input RC can be used to attenuate incoming signals
close to the filter clock frequency (Figure 10). A Bessel
passband response will be maintained if the value of the
input resistor follows Table 1.
Table 4. Aliasing Data
INPUT FREQUENCY OUTPUT FREQUENCY
0.9995 f
CLK
0.0005 f
CLK
–0.01 dB
0.995 f
CLK
0.005 f
CLK
–0.98 dB
0.99 f
CLK
0.01 f
CLK
–3.13 dB
0.9875 f
CLK
0.0125 f
CLK
–4.79 dB
0.985 f
CLK
0.015 f
CLK
– 7.21 dB
0.9825 f
CLK
0.0175 f
CLK
– 10.43 dB
0.98 f
CLK
0.02 f
CLK
– 14.14 dB
0.975 f
CLK
0.025 f
CLK
– 21.84 dB
0.97 f
CLK
0.03 f
CLK
– 28.98 dB
0.965 f
CLK
0.035 f
CLK
– 35.31 dB
0.96 f
CLK
0.04 f
CLK
– 40.94 dB
0.955 f
CLK
0.045 f
CLK
– 45.96 dB
0.95 f
CLK
0.05 f
CLK
– 50.46 dB
0.94 f
CLK
0.06 f
CLK
– 58.29 dB
0.93 f
CLK
0.07 f
CLK
– 64.90 dB
0.9 f
CLK
0.1 f
CLK
–80.20 dB
OUTPUT AMPLITUDE
REFERENCED TO
INPUT SIGNAL
V
IN
V
OUT
1065 F10
C
V
–
V
+
R
0.1µF
1
2
3
4
8
7
6
5
LTC1065
0.1µF
f
CLK
20 102πRC
≤ ≤
1
f
CLK
f
CLK
Figure 10. Adding an Input Anti-Aliasing RC