DC BY-PASSING CIRCUIT IN ANALOG INTERFACE

摘要

An analog interface circuit for the trunk or MODEM system has a DC bypass circuit to pass only the voice signal by removing the DC component. The DC bypass circuit comprises a miniaturized transformer (30) connected with a balancing network (20) and a CODEC (10), a relay switch (SW1) connected with terminals of a ring detector (40) and a relay driver (50), a bridge diode (B1) and a switching regulator (60). The circuit reduces the size of the transformer.