DESCRIPTION
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/fC); fC = Cutoff Frequency

where fC is the desired cutoff frequency. For many applications, this formula is all that is needed to design a filter. By simply utilizing different valued resistors, gain and other responses are achieved.

FEATURES
■ Extremely Easy to Use—A Single Resistor Value Sets the Cutoff Frequency (256Hz < fC < 256kHz)
■ Extremely Flexible—Different Resistor Values Allow Arbitrary Transfer Functions with or without Gain (256Hz < fC < 256kHz)
■ Supports Cutoff Frequencies Up to 360kHz Using FilterCADTM
■ 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 fC = 256kHz
■ fC Accuracy < ±2% (Typ)
■ DC Offset < 1mV
■ Cascadable to Form 8th Order Lowpass Filters
■ Available in Narrow SSOP-16 Package

APPLICATIONS
■ Discrete RC Active Filter Replacement
■ Antialiasing Filters
■ Smoothing or Reconstruction Filters
■ Linear Phase Filtering for Data Communication
■ Phase Locked Loops