AM79231

AM79231 ETC1 | Alldatasheet

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Pub. # 080248 Rev: C Amendment: /0 Issue Date: December 1999 Intelligent Access/Ge4 Voice Solutions DISTINCTIVE CHARACTERISTICS /G01 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 /G01 +5 V and battery supplies /G01 Dual battery operation for system power saving — Automatic battery switching — Intelligent thermal management /G01 Compatible with inexpensive protection networks — Accommodates low tolerance fuse resistors or PTC thermistors /G01 Metering capable — 12 kHz and 16 kHz — Smooth polarity reversal /G01 Tip-open state supports ground start signaling /G01 Ring relay driver for external ringing /G01 Integrated test load switches/relay drivers BLOCK DIAGRAM Two-Wire Interface AD SA BD SB HPB HPA TMN TMP VBL VBH RYE BGND VCCGND LD IMT ILG VREF VSAB VLB VTX RSN Signal Transmission Gain/Level ShiftLongitudinal Control Attenuator Thermal Management Control Fault Meas. Signal Conditioning Switch Driver Relay Drivers Relay Driver 1 Input Decoder and Control Registers Relay Control TMS CREF Am79231 Intelligent Subscriber Line Interface Circuit (ISLIC™ )

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. DISTINCTIVE CHARACTERISTICS OF THE INTELLIGENT ACCESS™ VOICE CHIPSET /G01 Performs all battery feed, ring-trip, signaling, hybrid and test (BORSCHT) functions /G01 Two chip solution supports high density, multi- channel architecture /G01 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 /G01 Supports external battery-backed ringing — Unbalanced ringing — Ring relay driver — Ring relay operation synchronized to zero cross- ings of ringing voltage and current — Integrated ring-trip filter and software enabled manual or automatic ring-trip mode /G01 Supports metering generation with envelope shaping /G01 Smooth or abrupt polarity reversal /G01 Adaptive transhybrid balance — Continuous or adapt and freeze /G01 Supports both loop-start and ground-start signaling /G01 Exceeds LSSGR and CCITT central office requirements /G01 Selectable PCM or GCI interface — Supports most available master clock frequen- cies from 512 kHz to 8.192 MHz /G01 On-hook transmission /G01 Power/service denial mode /G01 Line-feed characteristics independent of battery voltage /G01 Only 5 V, 3.3 V and battery supplies needed /G01 Low idle-power per line /G01 Linear power-feed with intelligent power- management feature /G01 Compatible with inexpensive protection networks; Accommodates low-tolerance fuse resistors while maintaining longitudinal balance /G01 Monitors two-wire interface voltages and currents for subscriber line diagnostics /G01 Built-in voice-path test modes /G01 Power-cross, fault, and foreign voltage detection /G01 Integrated line-test features — Leakage — Line and ringer capacitance — Loop resistance /G01 Integrated self-test features — Echo gain, distortion, and noise /G01 0 to 70°C commercial operation —– 40°C to 85°C extended temperature range available /G01 Small physical size /G01 Up to three relay drivers per ISLIC™ device — Configurable as test load switches

4 Am79231 Data Sheet

Figure 1. Example Four-Channel Linecard Block Diagram

3 P1-P3

Figure 2. Am79231 Block Diagram

6 Am79231 Data Sheet

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. J 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. DEVICE NAME/DESCRIPTION Am79231(Intelligent Subscriber Line Interface Circuit) TEMPERATURE RANGE C = Commercial (0°C to +70°C)* PACKAGE TYPE J = 32-pin plastic leaded chip carrier (PL032) Am79231 C Valid Combinations Am79231 JC 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.

8 Am79231 Data Sheet

Pin Pin Name I/O Description AD, BD A, B Line Drivers O Provide the currents to the A and B leads of the subscriber loop. BGND Ground Ground return for high and low battery supplies. CREF +3.3 VDC VCCD reference. It is the digital high logic supply rail, used by the ISLIC to ISLAC interface. GND Ground Analog and digital ground return for VCC. HPA, HPB High-Pass Filter Ca- pacitor O These pins connect to CHP , the external high-pass filter capacitor that separates the DC loop-voltage from the voice transmission path. ILG Longitudinal Current Sense O 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 Metallic Current Sense O 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 . LD Register Load I 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 ( <(Vref-0.3V) ), the logic levels on P1–P3 latch into the Am79231 control register bits that control the relay drivers (RD1–RD3). When the LD pin level is at ~VREF , the control register contents are locked. P1–P3 Control Bus I Inputs to the latch for the operating-mode decoder and the relay-drivers. R1 Ring Relay Driver O Collector connection for ring relay driver. Emitter internally connected to BGND. R2 Relay 2 Driver O Collector connection for relay 2 driver. Emitter internally connected to RYE R3 Relay 3 Driver O Collector connection for relay 3 driver. Emitter internally connected to RYE. RSN Receive Summing Node I The metallic current between AD and BD is equal to 500 times the current into this pin. Networks that program receive gain and two-wire impedance connect to this node. This input is at a virtual potential of VREF . RSVD Reserved This is used during Legerity testing. In the application, this pin must be left floating. RYE Relay 2, 3 Common Emitter O Emitter connection for R2 and R3. Normally connected to relay ground. SA, SB A, B Lead Voltage Sense I Sense the voltages on the line side of the fuse resistors at the A and B leads. External sense resistors, RSA and RSB, protect these pins from lightning or power-cross. TMP , TMN, TMS Thermal Management External resistors connected from TMP to TMS and TMN to VBL to offload excess power from the Am79231. VBH Battery (Power) Connection to high-battery supply used for ringing and long loops. Connects to the substrate. When only a single battery is available, it connects to both VBH and VBL. VBL Battery (Power) Connection to low-battery supply used for short loops. When only a single battery is available, this pin can be connected to VBH. VCC +5 V Power Supply Positive supply for low voltage analog and digital circuits in the Am79231. VLB Longitudinal Voltage I Sets the DC longitudinal voltage of the Am79231. It is the reference for the longitudinal control loop. When the VLB pin is greater than VREF , the Am79231 sets the longitudinal voltage to a voltage approximately half-way between the positive and negative power supply battery rails. When the VLB pin is driven to levels between 0V and VREF , the longitudinal voltage decreases linearly with the voltage on the VLB pin. VREF 1.4 V Analog Refer- ence I The ISLAC chip provides this voltage which is used by the Am79231 for internal reference purposes. All analog input and output signals interfacing to the ISLAC chip are referenced to this pin. VSAB Loop Voltage O Scaled-down version of the voltage between the sense points SA and SB on this pin. VTX 4-Wire Transmit Signal O The voltage between this pin and VREF is a scaled down version of the AC component of the voltage sensed between the SA and SB pins. One end of the two-wire input impedance programming network connects to VTX. The voltage at VTX swings positive and negative with respect to VREF .

The Intelligent Access/Ge4 voice chipsets integrate all functions of the subscriber line. Two chip types are used to implement the linecard; an Am79231 device and an ISLAC device. These provide the following basic functions: 1. The Am79231: A high voltage, bipolar device that drives the subscriber line, maintains longitudinal balance and senses line conditions. 2. The ISLAC device: A low voltage CMOS IC that provides conversion, control and DSP functions for the Am79231. Complete schematics of a linecard using the Intelligent Access voice chipsets for external ringing is shown in Figure 3. The Am79231 uses reliable, bipolar technology to provide the power necessary to drive a wide variety of subscriber lines. It can be programmed by the ISLAC device to operate in eight different modes that control power consumption and signaling. This enables it to have full control over the subscriber loop. The Am79231 is designed to be used exclusively with the ISLAC devices. The Am79231 requires only +5 V power and the battery supplies for its operation. The Am79231 implements a linear loop-current feeding method with the enhancement of intelligent Thermal Management. This limits the amount of power dissipated on the Am79231 chip by dissi- pating power in external resistors in a controlled manner. Each ISLAC device contains high-performance circuits that provide A/D and D/A conversion for the voice (codec), DC-feed and supervision signals. The ISLAC device contains a DSP core that handles signaling, DC-feed, supervision and line diagnostics for all channels. The DSP core selectively interfaces with three types of backplanes: /G01 Standard PCM/MPI /G01 Standard GCI /G01 Modified GCI with a single analog line per GCI channel The Intelligent Access voice chipset provides a complete software configurable solution to the BOR- SCHT functions as well as complete programmable control over subscriber line DC-feed character- istics, such as current limit and feed resistance. In addition, these chipsets provide system level solutions for the loop supervisory functions and metering. In total, they provide a programmable solution that can satisfy worldwide linecard requirements by software configuration. Software programmed filter coefficients, DC-feed data and supervision data are easily calculated with the WinSLAC /Ge4 software. This PC software is provided free of charge. It allows the designer to enter a description of system requirements. WinSLAC then computes the necessary coefficients and plots the predicted system results. The Am79231 interface unit inside the ISLAC device processes information regarding the line volt- ages, loop currents and battery voltage levels. These inputs allow the ISLAC device to place several key Am79231 performance parameters under software control. The main functions that can be observed and/or controlled through the ISLAC backplane interface are: /G01 DC-feed characteristics /G01 Ground-key detection /G01 Off-hook detection /G01 Metering signal /G01 Longitudinal operating point /G01 Subscriber line voltage and currents /G01 Ring-trip detection /G01 Abrupt and smooth battery reversal /G01 Subscriber line matching

10 Am79231 Data Sheet

/G01 Ringing /G01 Sophisticated line and circuit tests To accomplish these functions, the ISLIC device collects the following information and feeds it, in analog form, to the ISLAC device: /G01 The metallic (IMT) and longitudinal (ILG) loop currents /G01 The AC (VTX) and DC (VSAB) loop voltage The outputs supplied by the ISLAC device to the ISLIC device are then: /G01 A voltage (VHLi) that provides control for the following high-level ISLIC device outputs: — DC loop current — 12 or 16 kHz metering signal /G01 A low-level voltage proportional to the voice signal (VOUTi) /G01 A voltage that controls longitudinal offset for test purposes (VLBi) The ISLAC device performs the codec and filter functions associated with the four-wire section of the subscriber line circuitry in a digital switch. These functions involve converting an analog voice signal into digital PCM samples and converting digital PCM samples back into an analog signal. During conversion, digital filters are used to band-limit the voice signals. The user-programmable filters set the receive and transmit gain, perform the transhybrid balancing function, permit adjustment of the two-wire termination impedance and provide frequency attenua- tion adjustment (equalization) of the receive and transmit paths. Adaptive transhybrid balancing is also included. All programmable digital filter coefficients can be calculated using WinSLAC software. The PCM codes can be either 16-bit linear two's-complement or 8-bit companded A-law or µ-law. Besides the codec functions, the Intelligent Access voice chipset provides all the sensing, feedback, and clocking necessary to completely control ISLIC device functions with programmable parameters. System-level parameters under programmable control include active loop current limits, feed resis- tance, and feed mode voltages. The ISLAC device supplies complete mode control to the ISLIC device using the control bus (P1- P3) and tri-level load signal (LDi). The Intelligent Access voice chipset provides extensive loop supervision capability including off- hook, ring-trip and ground-key detection. Detection thresholds for these functions are programmable. A programmable debounce timer is available that eliminates false detection due to contact bounce. For subscriber line diagnostics, AC and DC line conditions can be monitored using built-in test tools. Measured parameters can be compared to programmed threshold levels to set a pass/fail bit. The user can choose to send the actual measurement data directly to a higher level processor by way of the PCM voice channel. Both longitudinal and metallic resistance and capacitance can be mea- sured, which allows leakage resistance, line capacitance, and telephones to be identified.

Figure 3. External Ringing Linecard Schematic chip may be replaced by Am79R251.

12 Am79231 Data Sheet

The following list defines the parts and part values required to meet target specification limits for channel i of the linecard (i = 1, 2, 3, 4). Notes: 1. Value can be adjusted to suit application. 2. Can be looser for relaxed ring-trip requirements. 3. Required for metering > 2.2 Vrms, otherwise may be omitted. 4. DT2i is optional - Should be put if there is a chance that this chip may be replaced by Am79R251. Item Type Value Tol. Rating Comments U1 Am79231 ISLIC device U2 Am79X22xx ISLAC device U5 TISP61089 80 V Transient Voltage Suppresser, Power Innova- tions DHi, DLi, DT1i, DT2i

4 Diode 100 mA 100 V 50 ns

RFAi, RFBi Resistor 50 Ω 2% 2 W Fusible PTC protection resistors RSAi, RSBi Resistor 200 k Ω 2% 1/4 W Sense resistors RTi Resistor 80.6 k Ω 1% 1/10 W RRXi Resistor 100 k Ω 1% 1/10 W RREF Resistor 69.8 k Ω 1% 1/10 W Current reference RMGLi, RMGPi Resistor 1 k Ω 5% 1 W Thermal management resistors RSHB, RSLB Resistor 750 k Ω 1% 1/8 W Battery Sense Resistors RHLai Resistor 40.2 k Ω 1% 1/10 W RHLbi Resistor 4.32 k Ω 1% 1/10 W RHLci Resistor 2.87 k Ω 1% 1/10 W RHLdi Resistor 2.87 k Ω 1% 1/10 W CHLbi Capacitor 3.3 nF 10% 10 V Not Polarized CHLdi Capacitor 0.82 µF 10% 10 V Ceramic RMTi Resistor 3.01 k Ω 1% 1/8 W Metallic Current Sense Resistors RLGi Resistor 6.04 k Ω 1% 1/8 W Longitudinal Current Sense Resistors RTEST Resistor 2 k Ω 1% 1 W Test board CADi, CBDi

1 Capacitor 22 nF 10% 100 V Ceramic, not voltage sensitive

CBATHi, CBATLi Capacitor 100 nF 20% 100 V Ceramic CHPi Capacitor 22 nF 20% 100 V Ceramic CSi1 Capacitor 100 nF 20% 100 V Protector speed –up capacitor CSSi3 Capacitor 56 pF 5% 100 V Ceramic RGFDi Resistor 510 Ω 2% 2 W 1.2 W typ RSRBi, RSRc Resistor 750 k Ω 2% 1/4 W Matched to within 0.2% for initial tolerance and 0 to 70° C ambient temperature range.2 17 mW typ KRi Relay 5 V Coil DPDT

ELECTRICAL CHARACTERISTICS

Loop resistance = 0 to ∞ unless otherwise noted (not including fuse resistors), 2 x 50 Ω fuse resistors, BATL = –36 V, BATH = –65 V, VCC = +5 V. For power dissipation measurements, DC-feed conditions are as follows: /G01 ILA (Active mode current limit) = 25 mA (IRSN = 50 µA) /G01 RFD (Feed resistance) = 500 Ω /G01 VAS (Anti-sat activate voltage) = 10 V /G01 VAPP (Apparent Battery Voltage) = 48 V /G01 RTMG1 = RTMG2 (Thermal management resistors) = 1 kΩ Description Test Conditions Min Typ Max Unit Power Dissipation Normal Polarity On-Hook Disconnect 50 mW On-Hook Standby 65 On-Hook Transmission ISLIC Fixed Longitudinal Voltage 145 On-Hook Active High Battery ISLIC 270 Off-Hook Active Low Battery ISLIC RL = 294 Ω TMG 620 200 Power Supply Currents On-Hook Disconnect VBH VBL VCC 0.5 0.1 3.1 mA On-Hook Standby VBH VBL VCC 0.75 3.1 On-Hook Transmission VBH Fixed Longitudinal Voltage VBL VCC 1.85 On-Hook Active High Battery VBH VBL VCC 3.6 7.3 Off-Hook Active Low Battery VBH RL = 294 Ω VBL VCC 26.9 7.5

14 Am79231 Data Sheet

The junction to air thermal resistance of the Am79231 in a 32-pin, PLCC package is 45 °C/W. The typical junction to case thermal resistance is 14°C/W. Measured under free air convection conditions and without external heatsinking. Absolute Maximum Ratings Operating Ranges Operating ranges define those limits between which device functionality is guaranteed. 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. Environmental Ranges Electrical Maximum Ranges Note: Vloopmax: Maximum expected loop voltage in application; I LOOP • maximum off-hook loop resistance. Vpk: Peak signal voltage for application. Storage temperature –55 to +150°C Ambient temperature, under bias –40 to +85°C Humidity TBD VCC with respect to GND –0.4 to +7 V VBH, VBL with respect to GND2 +0.4 to –70 V BGND with respect to GND –3 to +3 V Voltage on relay outputs +7 V AD or BD to BGND: Continuous VBH – 1 to BGND + 1 10 ms (F = 0.1 Hz) VBH – 5 to BGND + 5 1 µs (F = 0.1 Hz) VBH – 10 to BGND + 10 250 ns (F = 0.1 Hz) VBH – 15 to BGND + 15 Current into SA or SB: 10 µs rise to Ipeak; 1000 µs fall to 0.5 Ipeak; 2000 µs fall to I =0 Ipeak = ±5 mA Current into SA or SB: 2 µs rise to Ipeak; 10 µs fall to 0.5 Ipeak; 20 µs fall to I = 0 Ipeak = ±12.5 mA SA SB continuous 5 mA Current through AD or BD ± 150 mA P1, P2, P3, LD to GND –0.4 to VCC + 0.4 V ESD Immunity (Human Body Model) 1500 V min Maximum power dissipation, 1TA = 70°C TA = 85°C 1.67 W 1.33 W Notes: 1. Thermal limiting circuitry on chip will shut down the circuit at a junction temperature of about 165°C. The device should never see this temperature. Operation above 145°C junction temperature may degrade device reliability. 2. Rise time of VBH (dv/dt) must be limited to less than 27 v/ µs. Ambient Temperature 0 to 70 °C Commercial –40 to +85 °C extended temperature Ambient Relative Humidity 15 to 85% VCC 5 V ± 5% VBL –(Vloopmax + 6V + Vpk) to VBH V VBH –42.5 V to –70 V BGND with respect to GND –100 mV to +100 mV Load resistance on VTX to Vref 20 k Ω minimum Load resistance on VSAB to Vref 20 k Ω minimum

Target Specifications (See note 1) No. Item Condition Min Typ Max Unit Note

1 Two-wire loop voltage (in-

cluding offset) Standby mode, open circuit, |VBH| < 55 V |VBH| > 55 V Any Active mode (does not include OHT), RL = 600 Ω, I RSN = 50 µA OHT mode, RL = 600 Ω IRSN = 20 µA VBH – 8 13.88 8.64 19.8 VBH–7 10.8 VBH–6 55.5 16.13 12.96

2 Feed resistance per leg at

pins AD & BD Standby mode 130 250 375 Ω

3 Feed current limit Feed current

Standby mode, RL = 600 Ω 34 45 mA IMT current Standby mode, RL = 2200 Ω 44.6 56 µAILG current Standby mode A to VBH B to Ground

4 Ternary input voltage

boundaries for LD pin. Mid-level input source must be Vref. Low boundary High boundary Input high current Input low current Mid-level current CREF – 1 108 0.6 V V µA µA µA

5 Logic Inputs P1, P2, P3 Input high voltage

2.0 0.8 V V µA µA

6 VTX output offset –50 +50 mV

7 VREF input current VREF = 1.4 V .05 mA 3 8 CREF input current CREF = 3.3 V .09 mA 3 9 β, DC Ratio of VSAB to loop voltage: Tj < 145°C, VSA – VSB = 22 V 0.0088 0.0097 0.0106 V/V

10 Fault Indicator Threshold Voltage Output on IMT TBD CREF -

0.3 V CREF V 3

11 Gain from VLB pin to A or

30 V/V

12 VLB pin input current VLB = VREF ±1 V TBD mA

13 ILOOP/IMT ILOOP = 10 mA 275 300 325 A/A

14 ILONG/ILG ILONG = 10 mA 560 600 640 A/A

15 Input current, SA and SB

Active modes 1.0 3.0 µA 3

16 K1 Incremental DC current gain 500

A/A17 ISA/IMT Disconnect, ISA = 2 mA 6

18 ISB/ILG Disconnect, ISB = 2 mA 12

19 VSAB output offset TBD mV

20 IMT output offset -3 0 3 mV

21 ILG output offset -1 1 3 mV

β VSAB

16 Am79231 Data Sheet

Figure 4. Relay Driver Configuration

Am79231 Transmission Specifications No. Item Condition Min Typ Max Unit Note

1 RSN input impedance f = 300 to 3400 Hz 1 Ω 3

2 VTX output impedance 3

3 Max, AC + DC loop current Active High Battery or Active

4 Input impedance, A or B to GND Active mode 70 135 Ω

52 - 4 w i r e g a i n –10 dBm, 1 kHz, 0 to 70°C TA = –40°C to 85°C –14.13 –14.18 –13.98 –13.98 –13.83 –13.78 dB 6 2-4 wire gain variation with fre- quency 300 to 3400 Hz, relative to 1 kHz TA=–40°C to 85°C –0.1 +.1 7 2-4 wire gain tracking +3 dBm to –55 dBm Reference: –10 dBm TA = –40 to 85°C –0.1 TBD +0.1 6 84 - 2 w i r e g a i n –10 dBm, 1 kHz TA= –40°C to 85°C –0.15 0 TBD +0.15 9 4-2 wire gain variation with fre- quency 300 to 3400 Hz, relative to 1 kHz –0.1 +0.1 10 4-2 wire gain tracking +3 dBm to –55 dBm Reference: –10 dBm –0.1 +0.1 6

11 Total harmonic distortion level

4-wire overload level at VTX

300 Hz to 3400 Hz

11.2 dBm –12 dBm –0.8 dBm RLOAD = 600 Ω ±1 –50 –40 –48 –38 dB dB dB dB Vp 3

12 Idle channel noise

R L = 600 Ω 2-wire TA = –40 to 85°C 4-wire 2-wire T A = –40 to 85°C 4-wire TBD –83 TBD –97 +11 –79 dBrnC dBmp

13 Longitudinal balance

(IEEE method) Normal Polarity L - T 200 to 1000 Hz T A = –40°C to 0°C/70°C to 85°C 1000 to 3400 Hz TA = –40°C to 0°C/70°C to 85°C dB T - L 200 to 3400 Hz 40 L - T, IL = 0 50 to 3400 Hz 63 4 Reverse Polarity L - T 200 to 1000 Hz T A = –40°C to 0°C/70°C to 85°C

14 PSRR (VBH, VBL) 50 to 3400 Hz

3.4 to 50 kHz 25 45 4, 5 2, 3, 5

15 PSRR (VCC) 50 to 3400 Hz

3.4 to 50 kHz 25 45 4, 5 2, 3, 5

16 Longitudinal AC current per wire F = 15 to 60 Hz Active mode 20 30 mArms 3

17 Metering distortion Freq = 12 kHz 2.8 Vrms Freq = 16 kHz metering load = 200 Ω 40 dB 3

18 Am79231 Data Sheet

Am79231 Current-Limit Behavior Am79231 Fault Indications Notes: 1. Unless otherwise specified, test conditions are: VCC = 5 V, RMG1 = RMG2 = 1 k Ω, BATH = –65 V, BATL = 36 V, VBL = 34, RRX = 150 k Ω, RL = 600 Ω, RSA = RSB = 200 k Ω, RFA = RFB = 50 Ω, CHP = 22 nF , CAD = CBD = 22 nF , IRSN = 84 µA. DC-feed conditions are normally set by the ISLAC device. When the Am79231 is tested by itself, its operating conditions must be simulated as if it were connected to an ideal ISLAC device. 2. These tests are performed with the following load impedances: Frequency < 12 kHz – Longitudinal impedance = 500 Ω; metallic impedance = 300 Ω Frequency > 12 kHz – Longitudinal impedance = 90 Ω; metallic impedance = 135 Ω 3. Not tested or partially tested in production. This parameter is guaranteed by characterization or correlation to other tests. 4. This parameter is tested at 1 kHz in production. Performance at other frequencies is guaranteed by characterization. 5. When the Am79231 and ISLAC device is in the anti-sat operating region, this parameter is degraded. The exact degradation depends on system design. 6. –55 dBm gain tracking level not tested in production. This parameter is guaranteed by characterization and correlation to other tests. 7. This spec is valid from 0 V to VBL or –50 V, whichever is lower in magnitude. SLIC Mode Condition Min Typ Max Unit Note Disconnect Applied fault between ground and T/R VBH applied to Tip or Ring VBH/200 kΩ 100 µA A 7 Tip Open Ring Short to GND 32 34 37 mAStandby Short Tip-to-VBH Short Ring-to-GND Fault Indication Unit Note No Fault IMT operates normally (Vref ±1V) Thermal Shutdown IMT above 2.8 V; ILG operates normally 390 pf RT Network

30 K /G01 30 K /G01

bits RD1, RD2 and RD3. These are latched into the first three bits in the Am79231 control register. control data C1, C2, and C3, which are latched into the last three bits of the Am79231 control register. Connecting the LD pin to VREF locks the contents of the Am79231 control register. of the Am79231. Table 1 defines the Am79231 operating modes set by these signals. incorrect data loads to the relay bit latches of the Am79231 devices. ringing mode (RMODE = 1), enables the ring relay, and puts the Am79231 in the Standby mode. Table 1. Operating Modes

1. In these modes, the ring lead (B-lead) output has a –50 V internal clamp to battery ground (BGND).

000 Standby1 High Battery

001 Tip Open1 High Battery

010 O n - H o o k T r a n s m i s -

100 R S V D

111 R S V D

20 Am79231 Data Sheet

Table 2. Mode Descriptions usually perform the following functions. Table 3. Driver Descriptions RMTi and RLGi of and , respectively. Limit Behavior” section. In external ringing, the standby ISLIC state is selected. the current in the Ring lead is limited by an internal current source to 30 mA. amplifiers deliver the full power level determined by the programmed DC-feed conditions. is typically used during the voice part of a call. safety specifications for some classes of products. pin and VCCD. R1 drives the ring relay. current from a relay connected to VCCD.

Thermal-Management Equations (All Modes except Standby) TIMING SPECIFICATIONS Notes: 1. The P1 –3 pins are updated continuously during operation by the LD signal. 2. After a power-on reset or hardware reset, the relay outputs from the Am79231 turn all relays off. An unassuming state is to place the relay control pins, which are level triggered, to a reset state for all relays. Any noise encountered only raises the levels toward the register lock state. 3. When writing to the ISLIC registers, the sequence is: a. Set LD pin to mid-state b. Place appropriate data on the P1–3 pins c. Assert the LD pin to High or Low to write the proper data d. Return LD pin to mid-state 4. Am79231 registers are refreshed at 5.33 kHz when used with an ISLAC device. 5. If the clock or MPI becomes disabled, the LD pins and P1–3 returns to 0 V state, thus protecting the Am79231 and the line connection. 6. Not tested in production. Guaranteed by characterization. R3 A logic 1 on the RD3 signal turns the R3 driver on and routes current from the R3 pin to the RYE pin. In the option where the RYE pin is connected to ground, the R3 pin can sink current from a relay connected to VCCD. Another option is to connect the RYE pin to the B (Ring) lead through a diode and connect a test load between R3 and the A (Tip) lead. This technique avoids the use of a relay to connect a test load. However, it does not isolate the subscriber line from the linecard. The test load must be connected to the Am79231 side of the protection resistor to avoid damage to the R3 driver. I L < 5 mA PSLIC = (SBAT – ILRL)  IL + 0.3 W PTMG = 0 TMG resistor-current is limited to be 5 mA < IL. If IL < 5 mA, no current flows in the TMG resistor and it all flows in the Am79231. IL > 5 mA PSLIC = (SBAT – IL(RL + 2  RFUSE))*IL + 0.3 W – PTMG PTMG = (IL – 5 mA)^2  (RTMG1 + RTMG2) These equations are valid when RTMGX  (IL – 5m A ) < (SBAT – RLIL)/2 – 2 because the longitudinal voltage is one-half the battery voltage and the TMG switches require approximately 2 V. Symbol Signal Parameter Min Typ Max Unit trSLD LD Rise time Am79231 LD pin 2 µs tfSLD LD Fall time Am79231 LD pin 2 tSLDPW LD LD minimum pulse width 3 tSDXSU P1,P2,P3 P1 –3 data Setup time 4.5 tSDXHD P1,P2,P3 P1 –3 data hold time 4.5 tSDXD P1,P2,P3 Max P1 –3 data delay 5 Driver Description

22 Am79231 Data Sheet

P1,P2,P3 VREF VCC Write Relay Register Write State Register Lock RegistersLD P1,P2,P3 Relay Data State Data Write State Register Write Relay Register New Relay Data Previous Relay Data VREF VREF

 Revision A was a condensed version of the datasheet while Revision B contained the full version. Revision B to Revision C  Page 12, Linecard Parts List, Rows CHLbi and CHLdi: switched the numbers in the “Values” column. .050 REF..026 .032 TOP VIEW Pin 1 I.D. .485 .495.447 .453 .585 .595 .547 .553 16-038FPO-5 PL 032 DA79 6-28-94 ae SIDE VIEW SEATING PLANE .125 .140 .009 .015 .080 .095 .042 .056 .013 .021 .400 REF. .490 .530

Notes: www.legerity.com

Notes: www.legerity.com

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