AW: Re: AW: making LP filters into HP

[Haible_Juergen#Tel2743]

>> You can also get a HP response by switching each stage from
>> LP to HP: For HP, use the capacitor of each stage as input.
>
>Could you elaborate a little on this? What do you mean "as input"?

If you take the usual OTA-filter stage with resistor divider feedback:

* cap to GND, resistor as input => LP
* resistor to GND, cap as input => HP
* both resistor and cap as input => all pass

JH.