Description
The PBL 386 50/2 Subscriber Line Interface Circuit (SLIC) is a 90 V bipolar integrated circuit for use in Central Office Metering applications and other telecommunications equipment. The PBL 386 50/2 has been optimized for low total line interface cost and a high degree of flexibility in different applications.

Key Features
• 24-pin SSOP package
• Programmable two-wire signal headroom for 2.2 V rms metering
• High and low battery with automatic switching
• Only +5 V feed in addition to battery
• Selectable transmit gain (0.5x or 0.25x)
• 70 mW on-hook power dissipation in active state
• On-hook transmission
• Long loop battery feed tracks Vbat for maximum line voltage
• No power-up sequence
• 43V open loop voltage @ -48V battery feed
• Constant loop voltage for line leakage <5 mA (RLeak ~ >10 kΩ @ -48V)
• Full longitudinal current capability during on-hook state
• Analog over temperature protection permits transmission while the protection circuit is active
• Line voltage measurement
• Polarity reversal
• Ground key detector
• Tip open state with ring ground detector