LTC1563-2/LTC1563-3
Active RC, 4th Order
Lowpass Filter Family
FEATURES
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DESCRIPTIO
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Extremely Easy to Use—A Single Resistor Value
Sets the Cutoff Frequency (256Hz < f
C
< 256kHz)
Extremely Flexible—Different Resistor Values
Allow Arbitrary Transfer Functions with or without
Gain (256Hz < f
C
< 256kHz)
Supports Cutoff Frequencies Up to 360kHz Using
FilterCAD
TM
LTC1563-2: Unity-Gain Butterworth Response Uses a
Single Resistor Value, Different Resistor Values
Allow Other Responses with or without Gain
LTC1563-3: Unity-Gain Bessel Response Uses a
Single Resistor Value, Different Resistor Values
Allow Other Responses with or without Gain
Rail-to-Rail Input and Output Voltages
Operates from a Single 3V (2.7V Min) to
±5V
Supply
Low Noise: 36µV
RMS
for f
C
= 25.6kHz, 60µV
RMS
for
f
C
= 256kHz
f
C
Accuracy <
±2%
(Typ)
DC Offset < 1mV
Cascadable to Form 8th Order Lowpass Filters
Available in Narrow SSOP-16 Package
The LTC
®
1563-2/LTC1563-3 are a family of extremely
easy-to-use, active RC lowpass filters with rail-to-rail
inputs and outputs and low DC offset suitable for systems
with a resolution of up to 16 bits. The LTC1563-2, with a
single resistor value, gives a unity-gain Butterworth
response. The LTC1563-3, with a single resistor value,
gives a unity-gain Bessel response. The proprietary
architecture of these parts allows for a simple resistor
calculation:
R = 10k (256kHz/f
C
); f
C
= Cutoff Frequency
where f
C
is the desired cutoff frequency. For many appli-
cations, this formula is all that is needed to design a filter.
By simply utilizing different valued resistors, gain and
other responses are achieved.
The LTC1563-X features a low power mode, for the lower
frequency applications, where the supply current is re-
duced by an order of magnitude and a near zero power
shutdown mode.
The LTC1563-Xs are available in the narrow SSOP-16
package (Same footprint as an SO-8 package).
, LTC and LT are registered trademarks of Linear Technology Corporation.
FilterCAD is trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
APPLICATIO S
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Discrete RC Active Filter Replacement
Antialiasing Filters
Smoothing or Reconstruction Filters
Linear Phase Filtering for Data Communication
Phase Locked Loops
TYPICAL APPLICATIO
3.3V
0.1µF
LTC1563-2
1
2
3
R
R
R
V
IN
0.1µF
f
C
= 256kHz
4
5
6
7
8
LP
SA
NC
INVA
NC
LPA
AGND
V
–
V
+
LPB
NC
INVB
NC
SB
NC
EN
Single 3.3V, 256Hz to 256kHz Butterworth Lowpass Filter
16
15
14
13
12
11
10
9
R
R
R
V
OUT
GAIN (dB)
10
0
–10
–20
–30
–40
–50
–60
–70
–80
100
1k
100k
10k
FREQUENCY (Hz)
1M
1563 TA02
( )
10k
R
1563 TA01
U
Frequency Response
R = 10k
f
C
= 256kHz
R = 10M
f
C
= 256Hz
U
U
156323fa
1
LINER [ LINEAR TECHNOLOGY ]
