Description

The L8574 is a resistive subscriber line interface circuit (SLIC) that is optimized for long loop applications, such as Bellcore TR-NWT-000057 requirements for digital loop carrier (DLC) applications. It interfaces the low-voltage circuits on an analog line card to the Tip/Ring subscriber loop. The L8574 does not supply dc current to the subscriber loop; external resistors are used for this purpose.

Features

■ Low-power scan mode for low on-hook power dissipation (55 mW max)

■ Low active power dissipation; talk or on-hook transmission (240 mW max)

■ Distortion-free on-hook transmission

■ Eight operating states via latched paralleled data inputs with channel select feature

■ Precision fixed 28 mA current limiter

■ Integrated protection

■ No external protection device required

■ Integrated ringing access relay

■ Ring trip detector

■ Loop closure detector with hysteresis

■ Relay driver

■ Battery noise cancellation

■ Thermal protection

■ 44-pin, surface-mount, plastic package (PLCC)