Description
The L7591 Subscriber Line Interface Circuit (SLIC) Protector is designed to protect line-feed circuitry from fault-induced lightning and power-cross surge pulses. If a fault current forces TIP and/or RING to a more negative voltage than VS, current is conducted through the trip circuit. When the specified trip current level is reached, transistors PNPN1 and/or PNPN2 will turn on and "crowbar" the majority of the current to ground. If similar pulses force TIP and/or RING to a more positive state than ground, diodes D1 and/or D2 will conduct the pulse to ground. The L7591 SLIC Protector is available in an 8-pin, plastic DIP (L7591AB) and in an 8-pin, plastic SONB package (L7591AS).

Features
■ Shunts lightning pulses to ground
    — Positive or negative 30 A, 10 x 1000 µs
    — Positive or negative 40 A, 5 x 320 µs
    — Positive or negative 80 A, 2 x 10 µs
■ Power-cross protection
    — 3.5 APEAK, 50 Hz to 60 Hz, 1 s
    — 5.0 APEAK, 50 Hz to 60 Hz, 10 ms
■ Gate trigger current, 15 mA max
■ Up to –80 V capability
■ Holding current, 150 mA min