The HC-5524 telephone Subscriber Line Interface Circuit integrates most of the BORSCHT functions on a monolithic IC. The device is manufactured in a Dielectric Isolation (DI) process and is designed for use as a 24V interface between the traditional telephone subscriber pair (Tip and Ring) and the low voltage filtering and coding/decoding functions of the line card. Together with a secondary protection diode bridge, the device will withstand 500V induced surges, in plastic packages.

Features

• DI Monolithic High Voltage Process

• Compatible with Worldwide PBX and DLC Performance Requirements

• Controlled Supply of Battery Feed Current with Programmable Current Limit

• Operates with 5V Positive Supply (VB+)

• Internal Ring Relay Driver and a Utility Relay Driver

• High Impedance Mode for Subscriber Loop

• High Temperature Alarm Output

• Low Power Consumption During Standby Functions

• Switch Hook, Ground Key, and Ring Trip Detection

• Selective Power Denial to Subscriber

• Voice Path Active During Power Denial

• On-Chip Op Amp for 2-Wire Impedance Matching

Applications

• Solid State Line Interface Circuit for PBX or Digital Loop Carrier Systems

• Hotel/Motel Switching Systems

• Direct Inward Dialing (DID) Trunks

• Voice Messaging PBXs

• 2-Wire/4-Wire, 4-Wire/2-Wire Hybrid

• Related Literature

    - AN9607, Impedance Matching Design Equations

    - AN9628, AC Voltage Gain

    - AN9608, Implementing Pulse Metering

    - AN549, The HC-5502S/4X Telephone Subscriber Line Interface Circuits (SLIC)