Impedance synthesiser for telecommunications lines - includes voltage-to-current converter supplying reference impedance

摘要

The impedance synthesiser produces an impedance for the outputs of telecommunications line amplifiers, which is independent of the supplied d.c. biasing voltage. A particular advantage of the circuit is that it does not require an associated inverter circuit. - Operational amplifiers and MOSFET transistors are used in the construction of the converter as they have high input impedances and thus take negligible input currents. This means that output current is more accurately related to the input voltage than is the case with circuits using discrete junction transistors.