حفاظت مدار محدودکننده‌های ولتاژ گذرا (تی وی اس) تریستور محافظ اضافه‌ولتاژ (تی اس اس)

Product Attributes

Introduction

The TISP8200M/TISP8201M combination has been designed to protect dual polarity supply rail monolithic SLICs (Subscriber Line Interface Circuits) against overvoltages on the telephone line caused by lightning, a.c. power contact and induction. Protection against negative overvoltages is given by the TISP8200M. Protection against positive overvoltages is given by the TISP8201M. Both parts are in 8-pin small-outline surface mount packages.

The TISP8200M has an array of two buffered P-gate SCRs with a common anode connection. Each SCR cathode and gate has a separate terminal connection. The NPN buffer transistors reduce the gate supply current.

In use, the cathodes of the TISP8200M SCRs are connected to the two conductors of the POTS line. The gates are connected to the appropriate negative voltage battery feed of the SLIC driving the line conductor pair. This ensures that the TISP8200M protection voltage tracks the SLIC negative supply voltage. The anode of the TISP8200M is connected to the SLIC common.

Negative overvoltages are initially clipped close to the SLIC negative supply by emitter follower action of the NPN buffer transistor. If sufficient clipping current flows, the SCR will regenerate and switch into a low voltage on-state condition. As the overvoltage subsides, the high holding current of the SCR helps prevent d.c. latchup.

The TISP8201M has an array of two buffered N-gate SCRs with a common cathode connection. Each SCR anode and gate has a separate terminal connection. The PNP buffer transistors reduce the gate supply current.

In use, the anodes of the TISP8201M SCRs are connected to the two conductors of the POTS line. The gates are connected to the appropriate positive voltage battery feed of the SLIC driving that line pair. This ensures that the TISP8201M protection voltage tracks the SLIC positive supply voltage. The cathode of the TISP8201M is connected to the SLIC common.

Positive overvoltages are initially clipped close to the SLIC positive supply by emitter follower action of the PNP buffer transistor. If sufficient clipping current flows, the SCR will regenerate and switch into a low voltage on-state condition. As the overvoltage subsides, the SLIC pulls the conductor voltage down to its normal negative value and this commutates the conducting SCR into a reverse biassed condition.

Features

• TISP8200M, Negative Overvoltage Protector
  • Wide 0 to -90 V Programming Range
  • Low 5 mA max. Gate Triggering Current
  • High -150 mA min. Holding Current
• TISP8201M, Positive Overvoltage Protector
  • Wide 0 to +90 V Programming Range
  • Low -5 mA max. Gate Triggering Current
  • 20 mA min. Holding Current
• Rated for International Surge Wave Shapes