LTC1069-7
Linear Phase
8th Order Lowpass Filter
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
frequencyis50:1thatis,theinputsignalissampledtwice
perclockcycletolowertheriskofaliasing.TheLTC1069-
7 can be operated from a single 5V supply up to dual±5V
supplies.
FEATURES
■
8th Order, Linear Phase Filter in SO-8 Package
■
Raised Cosine Amplitude Response
■
–43dB Attenuation at 2× fCUTOFF
■
Wideband Noise: 140µVRMS
■
Operates from Single 5V Supply to
±5V Power Supplies
The gain and phase response of the LTC1069-7 can be
usedindigitalcommunicationsystemswherepulseshap-
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.
■
Clock-Tunable to 200kHz with ±5V Supplies
Clock-Tunable to 120kHz with Single 5V Supply
■
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APPLICATIONS
■
Digital Communication Filter
Antialiasing Filter with Linear Phase
Smoothing Filters
■
The LTC1069-7 has a wide dynamic range. With ±5V
supplies and an input range of 0.1VRMS to 2VRMS, the
signal-to-(noise + THD) ratio is ≥ 60dB. The wideband
noise of the LTC1069-7 is 140µVRMS. Unlike other
LTC1069-X filters, the typical passband gain of the
LTC1069-7 is equal to –1V/V.
■
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DESCRIPTION
The LTC®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
alphaofone. Thegainatthecutofffrequencyis–3dBand
the attenuation at twice the cutoff frequency is 43dB. The
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.
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TYPICAL APPLICATION
Frequency Response
10
Single 5V Supply, Linear Phase 100kHz Lowpass Filter
0
–10
–20
–30
–40
–50
–60
–70
AGND
V
OUT
V
OUT
5V
+
–
0.47µF
V
V
0.1µF
LTC1069-7
NC
NC
f
= 2.5MHz
1069-7 TA01
V
IN
V
IN
CLK
CLK
10
100
1000
FREQUENCY (kHz)
1069-7 TA02
1