I'm designing my first active filter for a simple fullrange project. I've decided to employ a variable baffle step compensator and two notch filter stages (I've attached the topologies). I understand an input buffer is needed before the first stage, but what about between stages? Is an output buffer necessary too?
Of the BSC filter, Rod Elliott says, "Opamp buffers at the input and output may be used if you cannot ensure that the source impedance is 100 ohms or less, and that the load impedance of the following stage is greater than 20k." How do I ensure that these conditions are met? If the notch follows the BSC stage, is the 5.11k resistor the load impedance?
I'm new at this, so if my questions are too trivial, please point me to some good references.
Of the BSC filter, Rod Elliott says, "Opamp buffers at the input and output may be used if you cannot ensure that the source impedance is 100 ohms or less, and that the load impedance of the following stage is greater than 20k." How do I ensure that these conditions are met? If the notch follows the BSC stage, is the 5.11k resistor the load impedance?
I'm new at this, so if my questions are too trivial, please point me to some good references.