LTC1063CN8#PBF Linear Technology, LTC1063CN8#PBF Datasheet - Page 11

• Manufacturer Part Number: LTC1063CN8#PBF
• Description: IC FILTER 5TH ORDER LOWPASS 8DIP
• Manufacturer: Linear Technology

Specifications of LTC1063CN8#PBF

• Filter Type: Butterworth, Lowpass Switched Capacitor
• Frequency - Cutoff Or Center: 50kHz
• Number Of Filters: 1
• Max-order: 5th
• Voltage - Supply: ±2.375 V ~ 8 V
• Mounting Type: Through Hole
• Package / Case: 8-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

APPLICATIO S I FOR ATIO
noise ratio at a given distortion level. The wideband noise
(µV
frequency and excludes the clock feedthrough. The
LTC1063’s typical wideband noise is 95µV
shows the same scope photo as Figure 8 but with a more
sensitive vertical scale: The clock feedthrough is imbed-
ded in the filter’s wideband noise. The peak-to-peak
wideband noise of the filter can be clearly seen; it is
approximately 500µV
95µV
factor or 5.25.
RMS
RMS
Figure 9. LTC1063 Output Clock Feedthrough + Noise
Figure 8. LTC1063 Output Clock Feedthrough + Noise
) is nearly independent of the value of the clock
f
f
CLK
CLK
wideband noise of the part, multiplied by a crest
= 100kHz, f
= 100kHz, f
C
C
= 1kHz, V
U
= 1kHz, V
P-P
. Note that 500µV
S
S
U
= ±5V, 1MHz SCOPE BW
= ±5V, 1MHz SCOPE BW
2µs/DIV
2µs/DIV
W
P-P
RMS
1063 F09
U
equals the
1063 F08
. Figure 9
Aliasing
Aliasing is an inherent phenomenon of sampled data filters
and it primarily occurs when the frequency of an input
signal approaches the sampling frequency. For the
LTC1063, an input signal whose frequency is in the range
of f
passband and stopband. Table 4 shows details.
Example:
An input RC can be used to attenuate incoming signals
close to the filter clock frequency (Figure 10). A Butterworth
passband response will be maintained if the value of the
input resistor follows Table 1.
Table 4. Aliasing Data
INPUT FREQUENCY
0.9995f
0.995 f
0.99 f
0.9875f
0.985 f
0.9825f
0.98 f
0.975 f
0.97 f
0.965 f
0.96 f
0.955 f
0.95 f
0.94 f
0.93 f
0.9
CLK
V
IN
±6% will generate an alias signal into the filter’s
f
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
0.1µF
Figure 10. Adding an Input Anti-Aliasing RC
V
–
R
C
LTC1063, f
f
f
IN
ALIAS
= (19.6kHz, 100mV
= (400Hz, 3.16mV
OUTPUT FREQUENCY
1
2
3
4
f
CLK
20
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
CLK
≤
LTC1063
2πRC
= 20kHz, f
1
f
f
f
f
f
f
f
f
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
≤
f
CLK
10
8
7
6
5
RMS
f
V
CLK
RMS
OUT
C
OUTPUT AMPLITUDE
)
= 200kHz,
REFERENCED TO
)
LTC1063
INPUT SIGNAL
– 100.3 dB
– 17.7 dB
– 10.2 dB
– 24.3 dB
– 30
– 40
– 48
– 54.5 dB
– 60.4 dB
– 65.5 dB
– 70.16 dB
– 78.25 dB
– 85.3 dB
– 3
1063 F10
0.1µF
V
0
0
+
dB
dB
dB
dB
dB
dB
11
1063fa