Datasheet

LTC1069-1
8
10691fa
APPLICATIONS INFORMATION
Aliasing
Aliasing is an inherent phenomenon of sampled data
systems and it occurs for input frequencies approaching
the sampling frequency. The internal sampling frequency
of the LTC1069-1 is 100 times its cutoff frequency. For
instance, if a 98kHz, 100mV
RMS
signal is applied at the
input of an LTC1069-1 operating with a 100kHz clock, a
2kHz, 28μV
RMS
alias signal will appear at the fi lter output.
Table 4 shows details.
Table 4. Aliasing (f
CLK
= 100kHz)
INPUT FREQUENCY
(V
IN
= 1V
RMS
)
(kHz)
OUTPUT LEVEL
(Relative to Input)
(dB)
OUTPUT FREQUENCY
(Aliased Frequency)
(kHz)
f
CLK
/f
C
= 100:1, f
CUTOFF
= 1kHz
96 (or 104)
97 (or 103)
98 (or 102)
98.5 (or 101.5)
99 (or 101)
99.5 (or 100.5)
–90.0
–86.0
–71.0
–56.0
–1.1
–0.21
4.0
3.0
2.0
1.5
1.0
0.5
TYPICAL APPLICATIONS
Single 3.3V Supply Operation with Output Buffer
Single 5V Operation with Power Shutdown
1
2
3
4
8
7
6
5
V
OUT
V
–
NC
CLK
AGND
V
+
NC
V
IN
0.1μF
0.47μF
SHUTDOWN
ON
5V
V
IN
V
OUT
1069-1 TA04
LTC1069-1
f
CLK
≤
750kHz
5V
0V
CMOS LOGIC
1
2
3
4
8
7
6
5
V
OUT
V
–
NC
CLK
AGND
V
+
NC
V
IN
0.1μF
0.47μF
V
IN
V
OUT
10691 TA05
LTC1069-1
f
CLK
500kHz
3.3V
0V
–
+
1/2 LT1366
3.3V
0.1μF