AM79231JC

Intelligent Accessä Voice Solutions Am79231 Intelligent Subscriber Line Interface Circuit (ISLIC™) DISTINCTIVE CHARACTERISTICS BLOCK DIAGRAM AD SA HPA HPB SB BD Two-Wire Interface TMN TMP TMS Thermal Management Control Fault Meas. VBL Switch Driver VBH R2 R3 RYE Relay Drivers Relay Control Input Decoder and Control Registers R1 Relay Driver 1 BGND GND




— 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

Monitor of two-wire interface voltages and currents supports +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
Signal Transmission RSN VTX Longitudinal Control Gain/Level Shift VLB Attenuator VSAB VREF Signal Conditioning IMT ILG CREF P1 P2 P3 LD VCC Pub. # 080248 Rev: C Amendment: /0 Issue Date: December 1999 TABLE OF CONTENTS Distinctive Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Distinctive Characteristics of the Intelligent Access™ Voice Chipset . . . . . . . . . . . . . . . . . . . . . . 3 Block Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Connection Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Intelligent Access™ Voice Chipsets Linecard With Am79231 . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Linecard Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Thermal Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Operating Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Environmental Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Electrical Maximum Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Target Specifications (See note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Relay Driver Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Am79231 Transmission Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Am79231 Current-Limit Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Am79231 Fault Indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Thermal-Management Equations (All Modes except Standby) . . . . . . . . . . . . . . . . . . 21 Timing Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Physical Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 PL032 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Revision Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Revision A to Revision B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Revision B to Revision C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 2 Am79231 Data Sheet The Am79231, in combination with an ISLAC™ device, implements the telephone line interface function. This enables the design of a low cost, high performance, fully software programmable line interface for multiple country applications worldwide. All AC, DC, and signaling parameters are fully programmable via microprocessor or GCI interfaces on the ISLAC device. Additionally, the Am79231 device has integrated self-test and line-test capabilities to resolve faults to the line or line circuit. The integrated test capability is crucial for remote applications where dedicated test hardware is not cost effective. Performs all battery feed, ring-trip, signaling, hybrid and test (BORSCHT) functions Two chip solution supports high density, multichannel architecture Single hardware design meets multiple country requirements through software programming of: — DC loop-feed characteristics and current-limit — Loop-supervision detection thresholds — Off-hook debounce circuit — Ground-key and ring-trip filters — Off-hook detect de-bounce interval — Two-wire AC impedance — Transhybrid balance — Transmit and receive gains — Equalization — Digital I/O pins — A-law/µ-law and linear selection Supports external battery-backed ringing — Unbalanced ringing — Ring relay driver — Ring relay operation synchronized to zero crossings of ringing voltage and current — Integrated ring-trip filter and software enabled manual or automatic ring-trip mode Supports metering generation with envelope shaping Smooth or abrupt polarity reversal Adaptive transhybrid balance — Continuous or adapt and freeze Supports both loop-start and ground-start signaling Am79231 Data Sheet
















DISTINCTIVE CHARACTERISTICS OF THE INTELLIGENT ACCESS™ VOICE CHIPSET Exceeds LSSGR and CCITT central office requirements Selectable PCM or GCI interface — Supports most available master clock frequencies from 512 kHz to 8.192 MHz On-hook transmission Power/service denial mode Line-feed characteristics independent of battery voltage Only 5 V, 3.3 V and battery supplies needed Low idle-power per line Linear power-feed with intelligent powermanagement feature Compatible with inexpensive protection networks; Accommodates low-tolerance fuse resistors while maintaining longitudinal balance Monitors two-wire interface voltages and currents for subscriber line diagnostics Built-in voice-path test modes Power-cross, fault, and foreign voltage detection Integrated line-test features — Leakage — Line and ringer capacitance — Loop resistance Integrated self-test features — Echo gain, distortion, and noise 0 to 70°C commercial operation — –40°C to 85°C extended temperature range available Small physical size Up to three relay drivers per ISLIC™ device — Configurable as test load switches







3 BLOCK DIAGRAMS Figure 1. Example Four-Channel Linecard Block Diagram 4 7 VCCA VCCD DGND1 DGND2 A1 B1 Am79231 VREF LD1 A2 B2 A3 B3 7 RC Networks and Protection Am79231 LD2 AGND1 AGND2 7 4 IO1-IO4 TSCA/G TSCB DRA/DD Am79231 3 LD3 P1-P3 A4 Am79231 B4 7 LD4 Quad ISLAC Am79Q2243 DRB DXB DXA/DU DCLK/S0 RREF 5 Ring-Trip Sense Resistors 5 PCLK/FS MCLK RSHB BATH RSLB FS/DCL CS/RST BATL DIO/S1 INT 4 Am79231 Data Sheet Figure 2. Am79231 Block Diagram A Amplifier AD IA SA IA sense IA 600 + Fault Meas. + - RSN HPA + VTX TMS BGND HPB Fault Meas. SB IB BD VREF + + + β = 0.01 VSAB B Amplifier IB sense IB 600 VREF VREF TMN VREF TMP Thermal Management Control To Power Amplifiers High Neg. Bat. sel. Gain/Level Shift VLB Thermal Shutdown VBH IA IB + 600 600 OHT Fixed Longitudinal Voltage Active High Battery Active Low Battery VBL R3 IMT IA IB − 600 600 Disconnect Tip Open ILG Reserved RYE R2 RD1 R1 Power amplifiers positive supply RD2 Decoder CREF RD3 C1 C2 Control Register C3 Demux P1 P2 P3 LD VCC GND BGND Am79231 Data Sheet Standby 5 ORDERING INFORMATION Legerity standard products are available in several packages and operating ranges. The ordering number (valid combination) is formed by a combination of the elements below. An ISLAC device must be used with this part. Am79231 J C TEMPERATURE RANGE C = Commercial (0°C to +70°C)* PACKAGE TYPE J = 32-pin plastic leaded chip carrier (PL032) DEVICE NAME/DESCRIPTION Am79231(Intelligent Subscriber Line Interface Circuit) Valid Combinations Am79231 JC Valid Combinations Valid combinations list configurations planned to be supported in volume for this device. Consult the local Legerity sales office to confirm availability of specific valid combinations, and to check on newly released valid combinations. Note: *Functionality of the device from 0°C to 70°C is guaranteed by production testing. Performance from –40°C to +85°C is guaranteed by characterization and periodic sampling of production units. 6 Am79231 Data Sheet CONNECTION DIAGRAM BGND 43 R1 R2 RYE R3 TMS TMP TMN P1 P2 5 6 7 8 9 10 11 12 13 2 1 32 31 30 29 28 27 SB SA IMT ILG CREF RSVD HPB HPA VTX RSVD 26 25 24 23 22 21 VREF VCC VBH VBL Am79231 32-Pin PLCC 14 15 16 17 18 19 20 LD VSAB VLB GND RSN P3 Am79231 Data Sheet BD AD 7 PIN DESCRIPTIONS Pin AD, BD BGND CREF GND HPA, HPB ILG IMT Pin Name A, B Line Drivers Ground +3.3 VDC Ground High-Pass Filter Capacitor Longitudinal Current Sense Metallic Current Sense I/O O Description Provide the currents to the A and B leads of the subscriber loop. Ground return for high and low battery supplies. VCCD reference. It is the digital high logic supply rail, used by the ISLIC to ISLAC interface. Analog and digital ground return for VCC. O O O These pins connect to CHP, the external high-pass filter capacitor that separates the DC loop-voltage from the voice transmission path. ILG is proportional to the common-mode line current (IAD–IBD), except in disconnect mode, where ILG is proportional to the current into grounded SB. IMT is proportional to the differential line current (IAD + IBD), except in disconnect mode, where IMT is proportional to the current into grounded SA. The Am79231 indicates thermal overload by pulling IMT to CREF. The LD pin controls the input latch and responds to a 3-level input. When the LD pin is a logic 1 ( >(Vref+0.3V) ), the logic levels on P1–P3 latch into the Am79231 control register bits that operate the mode-decoder. When the LD pin is a logic 0 (