Patent ID: 8442213

Claim:
A line card, comprising: a plurality of subscriber line interface circuits each having a first input terminal operable to receive power at a first positive reference voltage and a second input terminal operable to receive power at a second negative reference voltage; a plurality of interface lines each coupled to one of the subscriber line interface circuits for interfacing with subscriber lines external to the line card; a shared positive overvoltage protector including a shunting circuit coupled to all of the interface lines and referenced to the first positive reference voltage to provide positive overvoltage protection for all of said plurality of subscriber line interface circuits by shunting all of the interface lines responsive to a voltage on at least one of the interface lines exceeding the first positive reference voltage; and a plurality of negative overvoltage protectors referenced to the second negative reference voltage, wherein each of the negative overvoltage protectors is coupled to an associated one of the interface lines and is operable to provide negative overvoltage protection responsive to a voltage on the associated interface line exceeding the second negative reference voltage.