Description
The L7585F Full-Feature, Low-Power Subscriber Loop Interface Circuit (SLIC) and Switch integrates the battery feed, test access relay, and ringing relay that are necessary to interface a codec to the tip and ring of a subscriber loop into one low-power, low-cost package. It is built using a 90 V complementary bipolar (CBIC) process and a 320 V Bipolar-CMOS-DMOS (BCDMOS) process. The device is available in a 44-pin PLCC package.

Features
■ Low active power
■ Quiet tip/ring polarity reversal
■ Distortion-free on-hook transmission
■ 35 V to 60 V power supply operation
■ 14 operating states:
    — Forward battery active
    — Reverse battery active
    — Ground start (3)
    — Forward battery ring open
    — Reverse battery ring open
    — Reverse battery tip open
    — High impedance
    — Ringing (2)
    — Low current (2)
    — Disconnect
■ Self-test in all operating states
■ Independent, adjustable ac and dc parameters:
    — Switchhook detector threshold
    — Loop current limit
    — dc feed resistance
    — Termination impedance
■ Integrated ringing access relay
■ Integrated test-in relay
■ Integrated relay driver
■ Integrated ring trip detector
■ Thermal protection
■ 44-pin, surface-mount, plastic package (PLCC)