Subscriber Line Interface Circuit (SLIC) Including A Transient Output Current Limit Circuit And Related Method

Abstract

A subscriber line interface circuit (SLIC) for a subscriber loop includes a pair of output amplifiers for connection to the subscriber loop and a transient output current limit circuit. The transient output current limit circuit may have at least one programmable output current limit and limit respective output currents from the pair of output amplifiers based thereon. The transient output current limit circuit may limit both source and sink currents for each of the pair of output amplifiers.

Description

RELATED APPLICATION [0001] The present application is based upon co-pending provisional application Ser. No. 60 / 262,900 filed Jan. 19, 2001, which is hereby incorporated herein in its entirety by reference. FIELD OF THE INVENTION [0002] The present invention relates to the field of electronic circuits, and, more particularly, to subscriber line interface circuits (SLICs). BACKGROUND OF THE INVENTION [0003] A telephone network typically includes numerous switch offices which may be connected together via transmission lines, wireless links, etc. Central switching offices are connected to individual local telephone subscribers by subscriber loops. Each loop includes tip and ring wires carrying signals from the switch office to the telephone and from the telephone to the central office. A subscriber line interface circuit (SLIC) is typically used as the primary interface between the subscriber loop and the central office. Among other functions, the SLIC provides a direct current (DC) vo...

AI Technical Summary

Benefits of technology

"The invention is a SLIC (Supervised Line Inversion Circuit) that includes a transient current limit circuit. This circuit has programmable current limits for both source and sink currents, allowing for easy programming of current limits. The circuit also includes a reference current generator, source and sink comparators, and a transconductance stage. The programmable output current limit can be programmed using a programming resistor and a temperature stabilized voltage reference source. The SLIC can also include a DC loop current limit circuit for limiting current on the subscriber loop. The technical effect of this invention is to provide a flexible and programmable solution for limiting current on a subscriber loop."

Problems solved by technology

More particularly, the transient output current limit circuit may limit both source and sink currents for each of the pair of output amplifiers.

Further, the transient output current limit circuit may generate a source current limit and a sink current limit based upon the at least one programmable current limit.

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