AM79231

Intelligent Accessä Voice Solutions Am79231 Intelligent Subscriber Line Interface Circuit (ISLIC™) DISTINCTIVE CHARACTERISTICS
Monitor of two-wire interface voltages and currents supports — Voice transmission — Programmable DC feed characteristics — Independent of battery — Current limited — Selectable off-hook and ground-key thresholds — Subscriber line diagnostics — Leakage resistance — Loop resistance — Line capacitance — Bell capacitance — Foreign voltage sensing — Power cross and fault detection






+5 V and battery supplies Dual battery operation for system power saving — Automatic battery switching — Intelligent thermal management Compatible with inexpensive protection networks — Accommodates low tolerance fuse resistors or PTC thermistors Metering capable — 12 kHz and 16 kHz — Smooth polarity reversal Tip-open state supports ground start signaling Ring relay driver for external ringing Integrated test load switches/relay drivers BLOCK DIAGRAM AD SA HPA HPB SB BD Attenuator VSAB Two-Wire Interface Longitudinal Control Gain/Level Shift Signal Transmission RSN VTX VLB VREF Signal Conditioning IMT ILG CREF TMN TMP TMS Thermal Management Control Fault Meas. VBL Switch Driver VBH R2 R3 RYE Relay Drivers Relay Control P1 Input Decoder and Control Registers P2 P3 LD R1 Relay Driver 1 BGND GND VCC Pub. # 080248 Rev: C Amendment: /0 Issue Date: December 1999 TABLE OF CONTENTS Distinctive Characteristics . . . . . . . . . . . . . . . . . . . . . . ...