The LTC1064-4 is an 8th order, clock sweepable Cauer lowpass switched capacitor filter. An external TTL or CMOS clock programs the value of the filters cutoff frequency. With Pin 10 at V+, the fCLK to fCUTOFF ratio is 50:1; the filter has a Cauer response and with compensation the passband ripple is ±0.1dB. The stopband attenuation is 80dB at 2×fCUTOFF. Cutoff frequencies up to 100kHz can be achieved. With Pin 10 at V?, the fCLK to f?3dB ratio is 100:1, the filter has a transitional Butterworth-Cauer response with lower noise and lower delay nonlinearity than the Cauer response. The stopband attenuation at 2.5×f?3dB is 92dB. Cutoff frequencies up to 50kHz can be achieved. The LTC1064-4 features low noise and low harmonic distortion even when input voltages up to 3VRMS are applied. The LTC1064-4 overall performance competes with equivalent multiple op amp active realizations. The LTC1064-4 is pin compatible with the LTC1064-1, LTC1064-2 and LTC1064-3. The LTC1064-4 is manufactured using Linear Technology?s enhanced LTCMOS? silicon gate process.
