LTC1069-1
Low Power, 8th Order
Progressive Elliptic,
Lowpass Filter
EATURE
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8th Order Elliptic Filter in SO-8 Package
Operates from Single 3.3V to ±5V Power Supplies
–20dB at 1.2fCUTOFF
The cutoff frequency (fCUTOFF) of the LTC1069-1 is equal
to the clock frequency divided by 100. The gain at fCUTOFF
is –0.7dB and the typical passband ripple is ±0.15dB
up to 0.9fCUTOFF. The stopband attenuation of the
LTC1069-1 features a progressive elliptic response
reaching 20dB attenuation at 1.2fCUTOFF, 52dB attenua-
–52dB at 1.4fCUTOFF
–70dB at 2fCUTOFF
Wide Dynamic Range
110µV
Wideband Noise
tion at 1.4fCUTOFF and 70dB attenuation at 2fCUTOFF
.
RMS
3.8mA Supply Current with ±5V Supplies
2.5mA Supply Current with Single 5V Supply
2mA Supply Current with Single 3.3V Supply
With ±5V supplies, the LTC1069-1 cutoff frequency can
be clock-tuned up to 12kHz; with a single 5V supply, the
maximum cutoff frequency is 8kHz.
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The low power feature of the LTC1069-1 does not penal-
izethedevice’sdynamicrange.With±5Vsuppliesandan
input range of 0.3VRMS to 2.5VRMS, the signal-to-(noise
+ THD) ratio is ≥70dB. The wideband noise of the
LTC1069-1 is 110µVRMS. Other filter responses with
lower power or higher speed can be obtained. Please
contact LTC marketing for details.
PPLICATI
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Telecommunication Filters
Antialiasing Filters
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DESCRIPTIO
The LTC®1069-1 is a monolithic 8th order lowpass filter
featuringclock-tunablecutofffrequencyand2.5mApower
supply current with a single 5V supply. An additional
feature of the LTC1069-1 is operation with a single 3.3V
supply.
The LTC1069-1 is available in 8-pin PDIP and 8-pin SO
packages.
, LTC and LT are registered trademarks of Linear Technology Corporation.
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TYPICAL APPLICATI
Frequency Response
10
0
–10
–20
–30
–40
–50
–60
–70
Single 3.3V Supply 3kHz Elliptic Lowpass Filter
1
2
3
4
8
7
6
5
+
AGND
V
V
OUT
OUT
0.47µF
3.3V
0.1µF
+
–
V
V
LTC1069-1
NC
NC
f
CLK
V
V
CLK
IN
IN
300kHz
1069-1 TA01
–80
1.5
3
6
7.5
4.5
FREQUENCY (kHz)
1069-1 TA02
1