HC-5524

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


Application

• 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)


Pinout




Specifications

Maximum Supply Voltages
(VB+) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to 7V
(VB+) - (VB-) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40V
Relay Drive Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to 15V
Operating Conditions
Operating Temperature Range
HC-5524-5 . . . . . . . . . . . . . . . . . . . . . . . . . .  .. . 0 to TA to 75
HC-5524-9 . . . . . . . . . . . . . . . . . . . . . . . . .  .. -40 to TA to 85
Relay Driver Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . 5V to 12V
Positive Power Supply (VB+) . . . . . . . . . . . . . . . .. . . . . . 5V ±5%
Negative Power Supply (VB-). . . . . . . . . . . . . . . .  . . -20V to -28V


Description

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. The HC-5524 SLIC also maintains specified transmission performance in the presence of externally induced longitudinal currents. The BORSCHT functions that the SLIC provides are:

• Battery Feed with Subscriber Loop Current Limiting
• Overvoltage Protection
• Ring Relay Driver
• Supervisory Signaling Functions
• Hybrid Functions (with External Op-Amp)
• Test (or Battery Reversal) Relay Driver

In addition, the HC-5524 SLIC provides selective denial of power to subscriber loops, a programmable subscriber loop current limit from 20mA to 60mA, a thermal shutdown with an alarm output and line fault protection. Switch hook detection, ring trip detection and ground key detection functions are also incorporated in the SLIC device.

The HC-5524 SLIC is ideally suited for line card designs in PBX and DLC systems, replacing t