Method and apparatus for reducing switching oscillations in an ISDN line interface circuit

摘要

A method and apparatus for limiting switching oscillations on an ISDN line interface circuit may be accomplished by sensing the current provided to the primary winding of the line coupling transformer (14). When the primary current is in a first pre-determined range, a first control signal (64) is generated such that a first impedance is applied across the primary winding during a trailing edge of the transformer switching. When the primary current is within a second pre-determined range, a second control signal (66) is produced that causes a second impedance to be imposed across a primary winding during the trailing edge of the transformer switching.