AN2064 - APPLICATION NOTE

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Today and for several years to come, wireline networks remain an efficient and cost effective mean to ex-

change data around the world. The length of these copper lines require system designers to focus on line

interface protection. These protection stages must be in accordance with the standards where equipment

operates. This document has given the philosophy of such a protection and proposes practical results of

tests.

The modules tested were dedicated to US market for CO equipments and were equipped with two

TCP1.25A fuses from Cooper Bussmann and two SMP100MC-270 TRISIL from STMicroelectronics.

Same results have been found with two SMP100LC-270 and two TCP1.25A. The results of these

experiments proved the compliance of this solution with Telcordia (Bellcore) GR1089 standard. The same

approach can be used to protect other kinds of modules (i,e terminal) or CO modules for other countries.

Figure 13: Module behavior during 600V 3A 1.1s surge test

Figure 14: Module behavior during 600V 60A 5s surge test

I surge (2A/div)

V (100V/div)

I surge (50A/div)

V (100V/div)