FlexiSLIC, Telecom IC, 90V bipolar, 24-Pin DSO

The PBL38640/2 Subscriber Line Interface Circuit (SLIC) is a 90 V bipolar integrated circuit for use in PBX, Terminal adapters and other telecommunications equipment. The PBL 38640/2 SLIC has been optimized for low total line interface cost and for a high degree of flexibility in different applications. The PBL 38640/2 SLIC emulates resistive loop feed, programmable between 2x50 ? and 2x900 ?, with short loop current limiting adjustable to maximum 45 mA. In the current limited region the loop feed is nearly constant current with a slight slope corresponding to 2x30 k?. A second lower battery voltage may be connected to the device to reduce short loop power dissipation. The SLIC automatically switches between the two battery supply voltages without need for external components or external control. The SLIC incorporates loop current, ground key and ring-trip detection functions. The PBL38640/2 is compatible with both loop and ground start signalling. Two- to four-wire and four- to two-wire voice frequency (VF) signal conversion is accomplished by the SLIC in conjunction with either a conventional CODEC/filter or with a programmable CODEC/filter, for example SiCoFi PEB 2466. The programmable twowire impedance, complex or real, is set by a simple external network. Longitudinal voltages are suppressed by a feedback loop in the SLIC and the longitudinal balance specifications meet Bellcore TR909 requirements. The PBL 38640/2 SLIC package options are 24-pin SSOP, 24-pin PDSO or 28-pin PLCC.

• 24-pin SSOP package
• High and low battery with automatic switching
• 65 mW on-hook power dissipation in active state
• On-hook transmission
• Long loop battery feed tracks Vbat for maximum line voltage
• Selectable transmit gain (1x or 0.5 x)
• No power-up sequence
• 43 V open loop voltage @ -48 V battery feed
• Close tolerance current feeding
• Constant loop voltage for line leakage < 5 mA (RLeak ~ > 10 k? @ 48 V)
• Full longitudinal current capability during on-hook state
• Longitudinal balance > 60 dB
• Analog overtemperature protection permits transmission while the protection circuits is active
• Line voltage measurement
• Polarity reversal
• Ground key detector
• Tip open state with ring ground detector
• Programmable signal headroom
• -40° C to 85° C ambient temperature range