Second order active filters

Abstract From the Canadian patent

Abstract of the Disclosure A second order active filter comprises an input terminal an output terminal, and a, common terminal a capacitive T-network comprising three capacitors and in parallel, therewith, a resistive T-network comprising three resistors the terminals of the T-, networks being connected respectively via a first amplifier to the output terminal via a, buffer to the input terminal, and to the common terminal a potential divider between the, output and common terminals and a second amplifier having an input coupled to a tapping point of the potential divider and an output coupled via a resistor to the central junction of the capacitive T-network and via a capacitor to the …