New Low Noise (-120 dB) Filters from 100 Hz to 100 kHz D100 Series 4- and 8-pole low-pass and 2-pole pair band -pass fixed frequency filters provide low noise and distortion performance (-120 dB) in a small 32-pin DIP footprint. These plug-in ready to use modules are avaialable with corner frequencies (fc) from 100 Hz to 100 kHz.