SEMICONDUCT OR

1

April 1997

HC5520

CO/PABX Polarity Reversal

Subscriber Line Interface Circuit

Features

• Normal and Reversed DC Feed

• Current Limited Loop Feed

• Ringing, Test-In, and Test-Out Relay Drivers

• Thermal Shutdown Protection with Alert Signal

• On-Hook Transmission

• Selectable Transmit and Receive Gain Setting

• Selectable 2-Wire Impedance Matching

• Zero Crossing Ring Trip Detection and Ring Relay

Release

• Parallel Digital Control and Status Monitoring

• Protection Resistors Inside Feedback Loop Allows the

Use of PTC Devices Without Impact on Longitudinal

Balance

• Thermal Management Features

Applications

• CO/PABX Line Circuits

Description

The HC5520 is a Monolithic Subscriber Line Interface Circuit

(SLIC) for Analog Subscriber Line cards in Central Office

and PABX switches.

The HC5520 provides a comprehensive set of features for

these applications including loop reversal, zero crossing

ringing relay operation, long loop drive and a mutually inde-

pendent setting of the receive and transmit gains, and the

two wire impedance synthesis. Advanced power manage-

ment features combined with a small 44 lead MQFP pack-

age allow significant board space to be freed up for

additional line circuits.

The HC5520 is fabricated in a Harris state-of-the-art Bonded

Wafer High Voltage process, providing freedom from tradi-

tional JI latch-up phenomena without the use of additional

power supply filtering components or substrate tie connec-

tions. The very low parasitics and leakages associated with

this process provide an exceptionally flat performance over

frequency and temperature.

Block Diagram

Ordering Information

PART NUMBER

TEMP.

PACKAGE

PKG. NO.

HC5520CQ

0 to 70

44 Ld MQFP

Q44.10x10

HC5520CM

0 to 70

44 Ld PLCC

N44.65

TIP

TIPSEN

TEST

CONTROL

2-WIRE

INTERFACE

RING

CONTROL

AGND

BIAS

RINGSEN

RING

TA

TB

RD

POWER

MANAGEMENT

RGND

BGND

BATTERY

REFERENCE

LOGIC

TAI

PDI

RCI

PRI

TBI

TSDO

SHDO

HC5520

CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.

Copyright

File Number

4148.2