DESCRIPTION
The LTC®1562 is a low noise, low distortion continuous-time filter with rail-to-rail inputs and outputs, optimized for a center frequency (fO) of 10kHz to 150kHz. Unlike most monolithic filters, no clock is needed. Four independent 2nd order filter blocks can be cascaded in any combination, such as one 8th order or two 4th order filters. Each block’s response is programmed with three external resistors for center frequency, Q and gain, using simple design formulas. Each 2nd order block provides lowpass and bandpass outputs. Highpass response is available if an external capacitor replaces one of the resistors. Allpass, notch and elliptic responses can also be realized.

FEATURES
■ Continuous Time—No Clock
■ Four 2nd Order Filter Sections, 10kHz to 150kHz Center Frequency
■ ±0.5% Typical Center Frequency Accuracy
■ ±0.3% Typical Center Frequency Accuracy (A Grade)
■ Wide Variety of Response Shapes
■ Lowpass, Bandpass and Highpass Responses
■ 103dB Typical S/N, ±5V Supply (Q = 1)
■ 97dB Typical S/N, Single 5V Supply (Q = 1)
■ 96dB Typical S/(N + THD) at ±5V Supply, 20kHz Input
■ Rail-to-Rail Input and Output Voltages
■ DC Accurate to 3mV (Typ)
■ “Zero-Power” Shutdown Mode
■ Single or Dual Supply, 5V to 10V Total
■ Resistor-Programmable fO, Q, Gain

APPLICATIONS
■ High Resolution Systems (14 Bits to 18 Bits)
■ Antialiasing/Reconstruction Filters
■ Data Communications, Equalizers
■ Dual or I-and-Q Channels (Two Matched 4th Order Filters in One Package)
■ Linear Phase Filtering
■ Replacing LC Filter Modules