Coilless communications filter cct. - realises transfer function of low pass and bandpass filter for branching-off cct.

摘要

One of the circuit input terminal is directly connected to one of its output terminals, and this connection represents the reference potential. Two differential amplifiers (V1, V2) are connected in cascade through a resistor (R4) between the first amplifier output and the second amplifier inverting input. The input terminal not at the reference potential is connected through a resistor (R5) to the first amplifier inverting input. Each amplifier has a feedback through a capacitor (C2) between its output and inverting input, and a further feedback is provided through a resistor (R3) between the second amplifier output and first amplifier non-inverting input, also connected through a resistor to the reference potential. The second amplifier non-inverting input is directly connected to this potential.