SIMULTANEOUS EMI, SURGE, AND OVERVOLTAGE PROTECTION CIRCUIT
Original Publication Date: 1991-Dec-01
Included in the Prior Art Database: 2001-Dec-20
Figure 1 illustrates a circuit providing simultaneous EMI, surge, and over-voltage protection circuit 19 which meets three overlapping requirements for secure tele- phone communication equipment. This circuit provides a common lead for protection between multiple signal line pairs without affecting normal circuit operation and can operate without connection to earth ground for use in common mode applications.