LTC1164-7
Low Power, Linear Phase
8th Order Lowpass Filter
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DESCRIPTIO
EATURE
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F
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Better Than Bessel Roll-Off
The LTC1164-7 is a low power, clock-tunable monolithic
8th order lowpass filter with linear passband phase and
flat group delay. The amplitude response approximates a
maximally flat passband and exhibits steeper roll-off than
an equivalent 8th order Bessel filter. For instance, at twice
the cutoff frequency the filter attains 34dB attenuation
(vs12dB for Bessel), while at three times the cutoff fre-
quency the filter attains 68dB attenuation (vs 30dB for
Bessel). The cutoff frequency of the LTC1164-7 is tuned
via an external TTL or CMOS clock.
fCUTOFF up to 20kHz, Single 5V Supply
ISUPPLY = 2.5mA (Typ), Single 5V Supply
75dB THD + Noise with Single 5V Supply
Phase and Group Delay Response Fully Tested
Transient Response with No Ringing
Wide Dynamic Range
No External Components Needed
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PPLICATI
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Low power is achieved without sacrificing dynamic range.
With single 5V supply, the S/N + THD is up to 75dB.
Optimum 91dB S/N is obtained with ±7.5V supplies.
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Data Communication Filters
Time Delay Networks
Phase Matched Filters
The clock-to-cutoff frequency ratio of the LTC1164-7 can
be set to 50:1 (pin 10 to V+) or 100:1 (pin 10 to V–).
When the filter operates at the clock-to-cutoff frequency
ratio of 50:1, the input is double-sampled to lower the risk
of aliasing.
The LTC1164-7 is pin-compatible with the LTC1064-X
series and LTC1264-7.
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TYPICAL APPLICATI
Frequency Response
10kHz Linear Phase Lowpass Filter
1
2
3
4
5
6
7
14
13
12
11
10
9
GAIN
150
140
130
120
110
100
90
0
–10
–20
–30
–40
–50
–60
–70
–80
V
IN
–5V
LTC1164-7
CLK = 500kHz
5V
5V
DELAY
V
OUT
8
80
NOTE: THE POWER SUPPLIES SHOULD BE BYPASSED
BY A 0.1µF CAPACITOR CLOSE TO THE PACKAGE
AND ANY PRINTED CIRCUIT BOARD ASSEMBLY
SHOULD MAINTAIN A DISTANCE OF AT LEAST 0.2
INCHES BETWEEN ANY OUTPUT OR INPUT PIN AND
70
1
10
FREQUENCY (kHz)
100
THE f
LINE.
1164-7 TA01
CLK
1164-7 TA02
1