Please refer to the calculation tool for Chebyshev-type high-pass filters. The filters used in each of our homemade devices are of a fourth-order configuration, and the characteristics of each filter are shown in the attached photo (board unit). In this unit, the filter is inserted before the limiting amplifier, so it needs to be driven by a high power supply voltage. The high-voltage analog SWIC (TC9164) allows eight cutoff positions to be selected. If you insert it after the limiting amplifier, you can use the 74HC40 series and drive it at ±5V. However, if you insert it after the limiting amplifier, it can cut off the low-frequency components, but it has the disadvantage that the low-frequency components that are not transmitted by the limiting amplifier will be limited.

HPF board unit Schematic File HPF calculation
4th order HPF characteristics for each position
Fc=44Hz 4th order HPF characteristic
Fc=360Hz, 4th order HPF characteristic