LTC1069-6
Single Supply, Very Low
Power, Elliptic Lowpass Filter
FEATURES
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DESCRIPTION
The LTC
廬
1069-6 is a monolithic low power, 8th order low-
pass filter optimized for single 3V or single 5V supply
operation. The LTC1069-6 typically consumes 1mA under
single 3V supply operation and 1.2mA under 5V operation.
The cutoff frequency of the LTC1069-6 is clock tunable and it
is equal to the clock frequency divided by 50. The input signal
is sampled twice per clock cycle to lower the risk of aliasing.
The typical passband ripple is
鹵0.1dB
up to 0.9f
CUTOFF
.
The gain at f
CUTOFF
is 鈥?0.7dB. The transition band of the
LTC1069-6 features progressive attenuation reaching 42dB
at 1.3f
CUTOFF
and 70dB at 2.1f
CUTOFF
. The maximum
stopband attenuation is 72dB.
The LTC1069-6 can be clock tuned for cutoff frequencies
up to 20kHz (single 5V supply) and for cutoff frequencies
up to 14kHz (single 3V supply).
The low power feature of the LTC1069-6 does not penalize
the device鈥檚 dynamic range. With single 5V supply and an
input range of 0.4V
RMS
to 1.4V
RMS
, the Signal-to-(Noise
+ THD) ratio is
鈮?/div>
70dB. The wideband noise of the
LTC1069-6 is 125碌V
RMS
.
Other filter responses with higher speed can be obtained.
Please contact LTC Marketing for details.
The LTC1069-6 is available in an 8-pin SO package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
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8th Order Elliptic Filter in SO-8 Package
Single 3V Operation: Supply Current: 1mA (Typ)
f
CUTOFF
: 14kHz (Max)
S/N Ratio: 72dB
Single 5V Operation: Supply Current: 1.2mA (Typ)
f
CUTOFF
: 20kHz (Max)
S/N Ratio: 79dB
鹵0.1dB
Passband Ripple Up to 0.9f
CUTOFF
(Typ)
42dB Attenuation at 1.3f
CUTOFF
66dB Attenuation at 2.0f
CUTOFF
70dB Attenuation at 2.1f
CUTOFF
Wide Dynamic Range, 75dB or More (S/N + THD),
Under Single 5V Operation
Wideband Noise: 120碌V
RMS
Clock-to-f
CUTOFF
Ratio: 50:1
Internal Sample Rate: 100:1
APPLICATIONS
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Handheld Instruments
Telecommunication Filters
Antialiasing Filters
Smoothing Filters
Audio
Multimedia
TYPICAL APPLICATION
10
Frequency Response
V
IN
= 500mV
RMS
0
鈥?0
Single 3V Supply 10kHz Elliptic Lowpass Filter
AGND
3V
0.47碌F
0.1碌F
NC
V
IN
V
+
V
OUT
V
鈥?/div>
GAIN (dB)
鈥?0
鈥?0
鈥?0
鈥?0
LTC1069-6
NC
CLK
f
CLK
= 500kHz
1069-6 TA01
鈥?0
鈥?0
鈥?0
5
10
20
15
FREQUENCY (kHz)
25
1069-6 TA02
U
U
U
1
1
2
3
4
5
6
7
8
