LTC1563-2 Datasheet, PDF (1/20 Pages) Linear Technology – Active RC, 4th Order Lowpass Filter Family

LTC1563-2/LTC1563-3
Active RC, 4th Order
Lowpass Filter Family
FEATURES
■ _{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: 36µVRMS for fC = 25.6kHz, 60µVRMS for}
f_C = 256kHz
■ _{fC Accuracy < ±2% (Typ)}
■ _{DC Offset < 1mV}
■ _{Cascadable to Form 8th Order Lowpass Filters}
■ _{Available in NarroUw SSOP-16 Package}
APPLICATIO S
■ _{Discrete RC Active Filter Replacement}
■ _{Antialiasing Filters}
■ _{Smoothing or Reconstruction Filters}
■ _{Linear Phase Filtering for Data Communication}
■ _{Phase Locked Loops}
DESCRIPTIO
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.
TYPICAL APPLICATIO
Single 3.3V, 256Hz to 256kHz Butterworth Lowpass Filter
3.3V
0.1µF
R
R
R
V_IN
0.1µF
LTC1563-2
1
LP
2
SA
V^{+ 16}
15
LPB
3
NC
4
INVA
5
NC
14
NC
13
INVB
12
NC
6
LPA
7
AGND
8 _V–
11
SB
10
NC
9
EN
( ) ^{fC = 256kHz}
10k
R
V_OUT
R
R
R
1563 TA01
Frequency Response
10
0
–10
–20
–30
–40
–50
–60
–70
–80
100
R = 10k
f_C = 256kHz
R = 10M
f_C = 256Hz
1k
10k
100k
1M
FREQUENCY (Hz)
1563 TA02
156323fa
1