Thyristor TSPD 170V 7A 8-Pin SOIC T/R

The systems described often have the need to source two POTS (Plain Old Telephone Service) lines, one for a telephone and the other for a facsimile machine. In a single surface mount package, the TISP6NTP2C protects the two POTS line SLICs (Subscriber Line Interface Circuits) against overvoltages caused by lightning, a.c. power contact and induction.The TISP6NTP2C has an array of four buffered P-gate forward conducting thyristors with twin commoned gates and a common anode connection. Each thyristor cathode has a separate terminal connection. An antiparallel anode-cathode diode is connected across each thyristor. The buffer transistors reduce the gate supply current.In use, the cathodes of an TISP6NTP2C thyristors are connected to the four conductors of two POTS lines (see applications information). Each gate is connected to the appropriate negative voltage battery feed of the SLIC driving that line pair. By having separate gates, each SLIC can be protected at a voltage level related to the negative supply voltage of that individual SLIC. The anode of the TISP6NTP2C is connected to the SLIC common. The TISP6NTP2C voltage and current ratings also make it suitable for the protection of ISDN d.c. feeds of down to -115 V (ETSI Technical Report ETR 080:1993, ranges 1 to 5).Positive overvoltages are clipped to common by forward conduction of the TISP6NTP2C antiparallel diode. Negative overvoltages are initially clipped close to the SLIC negative supply by emitter follower action of the TISP6NTP2C buffer transistor. If sufficient clipping current flows, the TISP6NTP2C thyristor will regenerate and switch into a low voltage on-state condition. As the overvoltage subsides, the high holding current of the TISP6NTP2C helps prevent d.c. latchup.

• Dual Voltage-Programmable Protectors
• Supports Battery Voltages Down to -155 V
• Low 5 mA max. Gate Triggering Current
• High 150 mA min. (70 °C) Holding Current
• Specified 2/10 Limiting Voltage
• Small Outline Surface Mount Package
• Full 0 °C to 70 °C Temperature Range