INTERFACE ARRANGEMENT FOR A SUBSCRIBER SET

摘要

An interface is arranged between an integrated circuit which is provided for a 5 volt supply voltage and a variable-voltage telephone line. This circuit employs an MOS transistor whose current is controlled by a current regulating transistor and a current measuring resistor and includes a negative voltage feedback path for alternating current. A time constant is provided in order to disable the action of the current regulating transistor for transient or alternating currents.