4

 2003 Semtech Corp.

www.semtech.com

PROTECTION PRODUCTS

LC05-06

Figure 1 - Connection for Differential (Line-to-Line)

Protection of two Tip/Ring Line Pairs

Device Connection Options for Protection of Two

High-Speed Line Pairs

The LC05-6 is designed to protect four high-speed data

lines (two differential pairs) from transient over-volt-

ages which result from lightning and ESD. Protection

of two line pairs is achieved by connecting the device

as follows: Pins 1-4 are connected to line 1 of the first

pair (i.e. Tip 1) and pins 13-16 are connected to line 2

of the first pair (i.e. Ring 1). Pins 5-8 are connected to

line 1 of the second pair (i.e. Tip 2) and pins 9-12 are

connected to line 2 of the second pair (i.e. Ring 2). All

pins should be connected for best results. Minimize

parasitic inductance in the protection circuit path by

keeping the trace length between the protected line

and the LC05-6 as short as possible.

T1/E1 Linecard Protection

A typical T1/E1 linecard protection circuit is shown in

Figure 2. The LC05-6 is connected between Tip & Ring

on the transmit and receive line pairs. It provides

protection to metallic (line-to-line) lightning and ESD

surges. It is designed to meet the intra-building re-

quirements of Bellcore GR-1089. This design takes

advantage of the isolation of the transformer to

suppress common mode surges. To complete the

protection circuit, the SRDA05-4 (or SRDA3.3-4 for

3.3V supplies) is employed as the IC side protection

element. This device helps prevent the transceiver

from latching up by providing fine clamping of tran-

sients that are coupled through the transformer.

TIP 1

TIP 2

RING 1

RING 2

Applications Information