| 摘要 |
An integrated circuit telephone line protection module (10) that provides both overcurrent and overvoltage protection to a telephone line (12). A preferred embodiment of the module (10) contains a pair of bidirectional current carrying devices (60, 80). A shunt resistance (74, 94) is formed in series with each telephone line conductor (16, 18) so that when an overcurrent condition exists on one or both of the telephone line conductors, the respective bidirectional devices (60, 80) are driven into conduction, thereby short circuiting the excessive current to ground. Independent of the overcurrent protection functions, each bidirectional device (60, 80) is also responsive to an overvoltage condition on the telephone line (12) to thereby clamp or crowbar the overvoltage to ground.
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