LT1568CGN

有源滤波器 LT1568 - Very Low Noise, High Frequency Active RC, Filter Building Block

DESCRIPTION

The LT®1568 is an easy-to-use, active-RC filter building block with rail-to-rail inputs and outputs. The internal capacitors of the IC and the GBW product of the internal low noise op amps are trimmed such that consistent and repeatable filter responses can be achieved. With a single resistor value, the LT1568 provides a pair of matched 2-pole Butterworth lowpass filters with unity gain suitable for I/Q channels.

By using unequal-valued external resistors, the two 2-pole sections can create different frequency responses or gains. In addition, the two stages may be cascaded to create a single 4-pole filter with a programmable response. Capable of cutoff frequencies up to 10MHz, the LT1568 is ideal for antialiasing or channel filtering in high speed data communications systems. The LT1568 can also be used as a bandpass filter.

FEATURES

■ Up to 10MHz Center Frequency on a Single 3V Supply

■ Easy to Use—A Single Resistor Value Sets Lowpass Cutoff Frequency 200kHz ≤ ƒC ≤ 5MHz, Unequal Resistor Values Extend Cutoff Frequency Up to 10MHz

■ Extremely Flexible—Different Resistor Values Allow Lowpass Transfer Functions with or Without Gain Butterworth, Chebyshev or Custom

■ SNR = 92dB ƒC = 2MHz, 2VP-P

■ THD = –84dB ƒC = 2MHz, 1VP-P

■ Internal Capacitors Trimmed to ±0.75%

■ Single 4-Pole Lowpass Filter or Matched Pair of 2-Pole Lowpass Filters

■ Can be Connected as a Bandpass Filter

■ Single-Ended or Differential Output

■ Operates from Single 3V 2.7V Min to ±5V Supply

■ Rail-to-Rail Input and Output Voltages

APPLICATIONS

■ Replaces Discrete RC Active Filters and LC Filter Modules

■ Antialiasing/Reconstruction Filters

■ Dual or I-and-Q Channels Two Matched 2nd Order Filters in One Package

■ Single-Ended to Differential Conversion

■ Video Signal Processing