LTC1065 Linear Technology, LTC1065 Datasheet - Page 11

• Manufacturer Part Number: LTC1065
• Description: DC Accurate/ Clock-Tunable Linear Phase 5th Order Bessel Lowpass Filter
• Manufacturer: Linear Technology

A
Table 4. Aliasing Data
INPUT FREQUENCY
TYPICAL
PPLICATI
0.9995 f
0.995 f
0.99
0.9875 f
0.985 f
0.9825 f
0.98
0.975 f
0.97
0.965 f
0.96
0.955 f
0.95
0.94
0.93
0.9
–5V
–5V
f
f
f
f
f
f
f
f
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
Cascading Two LTC1065s for Steeper Roll-Off
0.1 F
0.1 F
A
V
O
PPLICATI
IN
f
WIDEBAND NOISE = 110 V
ATTENUATION AT f = 2f
C
OUTPUT FREQUENCY
U
1
2
3
4
1
2
3
4
(1/RC)(1/100)
S
0.0005 f
0.005 f
0.01
0.0125 f
0.015 f
0.0175 f
0.02
0.025 f
0.03
0.035 f
0.04
0.045 f
0.05
0.06
0.07
0.1
LTC1065
LTC1065
I FOR ATIO
U
R
f
f
f
f
f
f
f
f
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
O
C
8
7
6
5
8
7
6
5
= 60dB
U
RMS
W
V
S
OUT
OUTPUT AMPLITUDE
C
REFERENCED TO
INPUT SIGNAL
– 10.43 dB
– 14.14 dB
– 21.84 dB
– 28.98 dB
– 35.31 dB
– 40.94 dB
– 45.96 dB
– 50.46 dB
– 58.29 dB
– 64.90 dB
– 80.20 dB
– 3.13 dB
– 7.21 dB
– 0.01 dB
– 0.98 dB
– 4.79 dB
1065 TA04
U
0.1 F
0.1 F
5V
5V
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.
V
–5V
–5V
IN
Sharing Clock for Multichannel Applications
Figure 10. Adding an Input Anti-Aliasing RC
V
–
R
0.1 F
0.1 F
C
0.1 F
V
V
IN
IN
1
2
3
4
1
2
3
4
1
2
3
4
f
CLK
20
LTC1065
LTC1065
LTC1065
2 RC
R
1
f
CLK
10
8
7
6
5
8
7
6
5
8
7
6
5
V
OUT
f
V
CLK
OUT
C
V
LTC1065
OUT
1065 F10
0.1 F
V
1065 TA05
0.1 F
0.1 F
+
5V
5V
11