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PROTECTION PRODUCTS

SR70

Low Capacitance TVS Diode Array

Description

Features

Circuit Diagram

Schematic & PIN Configuration

Revision 04/18/03

RailClamps are surge rated diode arrays designed to

protect high speed data interfaces. The SR70 has

been specifically designed to protect sensitive compo-

nents which are connected to data and transmission

lines from over-voltages caused by ESD (electrostatic

discharge), EFT (electrical fast transients), and light-

ning. The SR70 has been optimized for use on ADSL

and other high-speed interfaces.

The unique design of the SR70 integrates four surge

rated, low capacitance steering diodes in a low profile

SOT-143 package. It has a typical capacitance of only

5pF and may be used to protect two high-speed lines

without sacrificing signal integrity. The SR70 is de-

signed to replace “standard” rectifiers that are not

rated for the high energy surges that are normally

expected in telecommunications applications.

During transient conditions, the steering diodes direct

the transient to either the positive side of the power

supply line or to ground. The maximum clamping

voltage seen by the protected circuit will be one diode

drop (V

The

SR70 may be used as a stand alone device or in

conjunction with TVS diodes for enhanced protection.

Applications

Mechanical Characteristics

ADSL Lines

Video Line Protection

T1/E1 secondary IC Side Protection

Portable Electronics

Microcontroller Input Protection

WAN/LAN Equipment

ISDN S/T Interface

Transient protection for high speed data lines to

IEC 61000-4-2 (ESD) ±15kV (air), ±8kV (contact)

IEC 61000-4-4 (EFT) 40A (5/50ns)

IEC 61000-4-5 (Lightning) 1kV, 24A (8/20µs)

Array of surge rated, low capacitance diodes

Protects two I/O lines

Low capacitance (5pF typical) for high-speed

interfaces

Low clamping voltage

Solid-state silicon-avalanche technology

JEDEC SOT-143 package

UL 497B listed

Molding compound flammability rating: UL 94V-0

Marking : R70

Packaging : Tape and Reel per EIA 481

Pin 4

Pin 2

Pin 3

Pin 1

SOT-143 (Top View)

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