Low Noise, High Frequency, 8th Order Butterworth Lowpass Filter

The LTC1064-2 is a monolithic 8th order lowpass Butterworth filter, which provides a maximally flat passband. The attenuation slope is -48dB/octave and the maximum attenuation is in excess of 80dB. An external TTL or CMOS clock programs the filter's cutoff frequency. The clock to cutoff frequency ratio is 100:1 (Pin 10 at V-) or 50:1 (Pin 10 at V+). The maximum cutoff frequency is 140kHz. No external components are needed.

The LTC1064-2 features low wideband noise and low harmonic distortion even for input voltages up to 3VRMS. In fact the LTC1064-2 overall performance competes with equivalent multiple op amp RC active realizations. The LTC1064-2 is available in a 14-pin DIP or 16-pin surface mounted SW package. The LTC1064-2 is fabricated using LTC?s enhanced analog CMOS Si-gate process.

The LTC1064-2 is pin compatible with the LTC1064-1.

Applications

* Antialiasing Filters

* Smoothing Filters

* Tracking High Frequency Lowpass Filters

* 8th Order Filter in a 14-Pin Package * 140kHz Maximum Corner Frequency * No External Components * 50:1 and 100:1 Clock to Cutoff Frequency Ratio * 80µVRMS Total Wideband Noise * 0.03% THD or Better * Operates from ±2.37V to ±8V Power Supplies