LTC1069-7
Linear Phase
8th Order Lowpass Filter
FEATURES
s
s
s
s
s
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8th Order, Linear Phase Filter in SO-8 Package
Raised Cosine Amplitude Response
鈥?43dB Attenuation at 2脳 f
CUTOFF
Wideband Noise: 140碌V
RMS
Operates from Single 5V Supply to
鹵5V
Power Supplies
Clock-Tunable to 200kHz with
鹵5V
Supplies
Clock-Tunable to 120kHz with Single 5V Supply
cutoff frequency of the LTC1069-7 is set by an external
clock and is equal to the clock frequency divided by 25.
The ratio of the internal sampling frequency to the cutoff
frequency is 50:1 that is, the input signal is sampled twice
per clock cycle to lower the risk of aliasing. The LTC1069-
7 can be operated from a single 5V supply up to dual
鹵5V
supplies.
The gain and phase response of the LTC1069-7 can be
used in digital communication systems where pulse shap-
ing and channel bandwidth limiting must be carried out.
Any system that requires an analog filter with linear phase
and sharper roll off than conventional Bessel filters can
use the LTC1069-7.
The LTC1069-7 has a wide dynamic range. With
鹵5V
supplies and an input range of 0.1V
RMS
to 2V
RMS
, the
signal-to-(noise + THD) ratio is
鈮?/div>
60dB. The wideband
noise of the LTC1069-7 is 140碌V
RMS
.
Unlike other
LTC1069-X filters, the typical passband gain of the
LTC1069-7 is equal to 鈥?V/V.
The LTC1069-7 is available in an SO-8 package.
Other filter responses with lower power/speed specifica-
tions can be obtained. Please contact LTC Marketing.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIONS
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Digital Communication Filter
Antialiasing Filter with Linear Phase
Smoothing Filters
DESCRIPTION
The LTC
廬
1069-7 is a monolithic, clock-tunable, linear
phase, 8th order lowpass filter. The amplitude response
of the filter approximates a raised cosine filter with an
alpha of one. The gain at the cutoff frequency is 鈥?3dB and
the attenuation at twice the cutoff frequency is 43dB. The
TYPICAL APPLICATION
Frequency Response
10
Single 5V Supply, Linear Phase 100kHz Lowpass Filter
AGND
5V
0.47碌F
0.1碌F
NC
V
IN
V
IN
V
+
LTC1069-7
NC
CLK
f
CLK
= 2.5MHz
1069-7 TA01
V
OUT
V
鈥?/div>
GAIN (dB)
U
U
U
0
鈥?0
鈥?0
鈥?30
鈥?40
鈥?50
鈥?60
鈥?0
10
100
FREQUENCY (kHz)
1000
1069-7 TA02
V
OUT
1
1
2
3
4
5
6
7
8
