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Intelligent AccessTM Voice Solutions
AM79R251
Intelligent Subscriber Line Interface Circuit (ISLICTM)
DISTINCTIVE CHARACTERISTICS
s Monitor of two-wire interface voltages and currents supports -- Voice transmission -- Through chip ring generation -- 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 s Supports internal and external ringing -- High voltage operation supports long loops s +5 V and battery supplies s Dual battery operation for system power saving -- Automatic battery switching -- Intelligent thermal management s Compatible with inexpensive protection networks -- Accommodates low tolerance fuse resistors or PTC thermistors s Metering capable -- 12 kHz and 16 kHz -- Smooth polarity reversal s Tip-open state supports ground start signaling s Integrated test load switches/relay drivers
BLOCK DIAGRAM
RSN AD SA HPA HPB SB BD Attenuator VSAB Two-Wire Interface Longitudinal Control Gain/Level Shift Signal Transmission VTX
VLB
VREF Signal Conditioning IMT ILG
TMN TMP TMS VBP VBL
Thermal Management Control Fault Meas
CREF
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. # 22480 Rev: C Amendment: /0 Issue Date: December 1999
TABLE OF CONTENTS
Distinctive Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Distinctive Characteristics of the Intelligent AccessTM Voice Chipset . . . . . . . . . . . . . . . . . . . . . . 3 Block Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Connection Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Intelligent AccessTM Voice Chipsets Linecard With AM79R251 . . . . . . . . . . . . . . . . . . . . . . . . . 11 Linecard Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Thermal Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Operating Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Environmental Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Electrical Maximum Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Target Specifications (See note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Relay Driver Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 AM79R251 Transmission Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 AM79R251 Ringing Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 AM79R251 Current-Limit Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 AM79R251 Fault Indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Thermal-Management Equations (All Modes except Standby) . . . . . . . . . . . . . . . . . . 23 Timing Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Physical Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 PL032 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Revision Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Revision A to Revision B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Revision B to Revision C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2
AM79R251
The AM79R251, in combination with an ISLACTM 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 AM79R251 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 ACCESSTM VOICE CHIPSET
s Performs all battery feed, ringing, signaling, hybrid and test (BORSCHT) functions s Two chip solution supports high density, multichannel architecture s Single hardware design meets multiple country requirements through software programming of: -- Ringing waveform and frequency -- 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/-law and linear selection s Supports internal and external battery-backed ringing -- Self-contained ringing generation and control -- Supports external ringing generator and ring relay -- 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 s Supports metering generation with envelope shaping s Smooth or abrupt polarity reversal s Adaptive transhybrid balance -- Continuous or adapt and freeze s Supports both loop-start and ground-start signaling s Exceeds LSSGR and CCITT central office requirements s Selectable PCM or GCI interface -- Supports most available master clock frequencies from 512 kHz to 8.192 MHz s On-hook transmission s Power/service denial mode s Line-feed characteristics independent of battery voltage s Only 5 V, 3.3 V and battery supplies needed s Low idle-power per line s Linear power-feed with intelligent powermanagement feature s Compatible with inexpensive protection networks; Accommodates low-tolerance fuse resistors while maintaining longitudinal balance s Monitors two-wire interface voltages and currents for subscriber line diagnostics s Built-in voice-path test modes s Power-cross, fault, and foreign voltage detection s Integrated line-test features -- Leakage -- Line and ringer capacitance -- Loop resistance s Integrated self-test features -- Echo gain, distortion, and noise s 0 to 70C commercial operation -- -40C to 85C extended temperature range available s Small physical size s Up to three relay drivers per ISLICTM device -- Configurable as test load switches
AM79R251
3
BLOCK DIAGRAMS
Figure 1. Example Four-Channel Linecard Block Diagram
4
AM79R251
Figure 2.
AM79R251 Block Diagram
AD IA SA
IA sense
IA 600
RSN
A Amplifier
Fault Meas. HPA Active High Voltage VBP Power Amplifiers Positive Supply + + -
+ -
+
VTX
TMS BGND HPB Fault Meas. SB IB BD
VREF
+
+ = 0.00667 -
VSAB
B Amplifier IB sense
IB 600
VREF VREF
TMN
VREF
TMP
Thermal Management Control
To Power Amplifiers
Gain/Level Shift
VLB
VBH
High Neg Batt Sel
Thermal Shutdown IA IB + 600 600
VBL R3
OHT Fixed Longitudinal Voltage Active Boosted Battery
IMT
Active High Battery
Active Low Battery
Internal Ringing
IA IB - 600 600
Disconnect Tip Open
ILG
RYE
Decoder R2 RD1 R1 RD2 RD3 C1 C2 Control Register C3 CREF
Demux
P1 P2 P3 LD VCC GND
BGND
AM79R251
Standby
5
ORDERING INFORMATION
AMD 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.
AM79R251 J C
TEMPERATURE RANGE C= Commercial (0C to +70C)*
PACKAGE TYPE J = 32-pin plastic leaded chip carrier (PL032) DEVICE NAME/DESCRIPTION AM79R251 Intelligent Subscriber Line Interface Circuit
Valid Combinations AM79R251 JC
Valid Combinations Valid combinations list configurations planned to be supported in volume for this device. Consult the local AMD sales office to confirm availability of specific valid combinations, and to check on newly released valid combinations.
Note: *Functionality of the device from 0C to 70C is guaranteed by production testing. Performance from -40C to +85C is guaranteed by characterization and periodic sampling of production units.
6
AM79R251
CONNECTION DIAGRAM
BGND
VCC
VBH
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
VBP 26 25 24 23 22 21 VREF
VBL
AM79R251 32-Pin PLCC
14 15 16 17 18 19 20 LD VSAB VLB GND RSN P3
AM79R251
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 AM79R251 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 AM79R251 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 AM79R251 control register bits that control the relay drivers (RD1-RD3). When the LD pin level is at ~VREF, the control register contents are locked. Inputs to the latch for the operating-mode decoder and the relay-drivers. Collector connection for relay 1 driver. Emitter internally connected to BGND. Collector connection for relay 2 driver. Emitter internally connected to RYE Collector connection for relay 3 driver. Emitter internally connected to RYE. 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. This is used during AMD testing. In the application, this pin must be left floating. Emitter connection for R2 and R3. Normally connected to relay ground. 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. External resistors connected from TMP to TMS and TMN to VBL to offload excess power from the AM79R251. 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. Connection to low-battery supply used for short loops. When only a single battery is available, this pin can be connected to VBH. Used in Ringing State and for Extended Loop operation. Positive supply for low voltage analog and digital circuits in the AM79R251.
LD
Register Load
I
P1-P3 R1 R2 R3 RSN
Control Bus Relay 1 Driver Relay 2 Driver Relay 3 Driver Receive Summing Node Reserved Relay 2, 3 Common Emitter A, B Lead Voltage Sense Thermal Management Battery (Power) Battery (Power) Positive Battery (Power) +5 V Power Supply Longitudinal Voltage
I O O O I
RSVD RYE SA, SB TMP, TMN, TMS VBH VBL VBP VCC VLB
O I
I
Sets the DC longitudinal voltage of the AM79R251. It is the reference for the longitudinal control loop. When the VLB pin is greater than VREF, the AM79R251 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. The ISLAC chip provides this voltage which is used by the AM79R251 for internal reference purposes. All analog input and output signals interfacing to the ISLAC chip are referenced to this pin. Scaled-down version of the voltage between the sense points SA and SB on this pin. 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.
VREF
1.4 V Analog Reference Loop Voltage 4-Wire Transmit Signal
I
VSAB VTX
O O
8
AM79R251
GENERAL DESCRIPTION
The Intelligent Access voice chipsets integrate all functions of the subscriber line. Two chip types are used to implement the linecard; an AM79R251 device and an ISLAC device. These provide the following basic functions: 1. The AM79R251: 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 AM79R251. Complete schematics of linecards using the Intelligent Access voice chipsets for internal and external ringing are shown in Figure 3 and Figure 4. The AM79R251 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 AM79R251 is designed to be used exclusively with the ISLAC devices. The AM79R251 requires only +5 V power and the battery supplies for its operation. The AM79R251 implements a linear loop-current feeding method with the enhancement of intelligent Thermal Management. This limits the amount of power dissipated on the AM79R251 chip by dissipating 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: * * * Standard PCM/MPI Standard GCI Modified GCI with a single analog line per GCI channel
The Intelligent Access voice chipset provides a complete software configurable solution to the BORSCHT functions as well as complete programmable control over subscriber line DC-feed characteristics, 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 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 AM79R251 interface unit inside the ISLAC device processes information regarding the line voltages, loop currents and battery voltage levels. These inputs allow the ISLAC device to place several key AM79R251 performance parameters under software control. The main functions that can be observed and/or controlled through the ISLAC backplane interface are: * * * * * * * * DC-feed characteristics Ground-key detection Off-hook detection Metering signal Longitudinal operating point Subscriber line voltage and currents Ring-trip detection Abrupt and smooth battery reversal AM79R251 9
* * *
Subscriber line matching Ringing generation 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: * * The metallic (IMT) and longitudinal (ILG) loop currents The AC (VTX) and DC (VSAB) loop voltage
The outputs supplied by the ISLAC device to the ISLIC device are then: * A voltage (VHLi) that provides control for the following high-level ISLIC device outputs: -- DC loop current -- Internal ringing signal -- 12 or 16 kHz metering signal * * A low-level voltage proportional to the voice signal (VOUTi) 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 attenuation 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 -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 resistance, 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 offhook, 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 measured, which allows leakage resistance, line capacitance, and telephones to be identified.
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AM79R251
INTELLIGENT ACCESSTM VOICE CHIPSETS LINECARD WITH AM79R251
Figure 3. Internal Ringing Linecard Schematic
+5V RSAi SA A RFAi AD CHLbi RHLbi VCC 3.3V CREF RSN RHLai RRXi VOUTi DGND
VHLi RTESTMi U3 U5 RHLci RTi CADi VSAB CHPi BATH DT1i VTX U4 U6 CSSi B RFBi BD VLB RSBi SB CBDi TMS DT2i RMGPi ILG TMP RLGi TMN VREF RMGLi U1 AM79R251 RMTi VREF VILGi U2 ISLAC BACK PLANE IMT VLBi VIMTi HPB VINi CS1 CS2 BATP HPA VSABi RHLdi CHLdi AGND
VREF VCCA VCCD VCC +3.3VDC
DHi BATH DLi BATL VBL LD GND CBATHi CBATLi P1 P2 P3 BATP VBP RYE R2
RTESTLi
VBH
VREF
VREF
LDi
SBP RSPB SLB RSLB SHB RSHB IREF RREF
BATP BATL BATH
P1 P2 P3
CBATPi
R3 R1 BGND RSVD
* CSS required for > 2.2 VRMS metering ** Connections shown for one channel
AM79R251
11
Figure 4.
External Ringing Linecard Schematic
+5 V RSAi VCC SA 3.3 V CREF RSN RHLai RRXi VOUTi DGND RHLbi
A
RFAi AD
KRi(A)
CHLbi
VHLi U3 RTESTMi VSAB CHPi DT1i BATH CS1 CS2 BATP HPA VTX U5
CADi
AGND
RHLci RTi
RHLdi CHLdi VCCA VSABi VINi VCCD
VREF VCC +3.3 VDC
U4
U6
HPB CSSi VLB
CBDi
B
RFBi
VLBi VIMTi RMTi
BD RSBi SB TMS DT2i RMGPi U1 AM79R251
IMT
KRi (B)
VREF ILG VILGi U2 ISLAC RLGi
TMP VREF TMN RMGLi VREF VREF
BACK PLANE
DHi BATH DLi BATL VBL VBH
LD GND P1 P2
LDi
P1 P2 P3 SLB RSLB SPB RSPB BATL BATP
CBATHi
CBATLi
P3
CBATPi SHB BATP VBP RYE R2H
RTESTLi
BATH RSHB
IREF RREF
R3H
RGFDLi
R1 KRi +5V * CSS required for > 2.2 VRMS metering ** Connections shown for one channel BGND RSVD XSBi XSC
Ring Bus RSRBi
RSRC
12
AM79R251
LINECARD PARTS LIST
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). Item
U1 U2 U3, U4 U5, U6 D1, D2 DHi, DLi, DT1i, DT2i RFAi, RFBi RSAi, RSBi RTi RRXi RREF RMGLi, RMGPi RSHB, RSLB RHLai RHLbi RHLci RHLdi CHLbi CHLdi RMTi RLGi RTESTMi RTESTLi CADi, CBDi
1
Type
AM79R251
Value
Tol.
Rating
ISLIC device
Comments ISLAC device
Am79X22xx
P1001SC -- Diode Diode Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Capacitor Capacitor Resistor Resistor Resistor Resistor Capacitor Capacitor Capacitor CS2i1 Capacitor Capacitor Resistor Resistor 1A 100 mA 50 200 k 80.6 k 100 k 69.8 k 1 k 750 k 40.2 k 4.32 k 2.87 k 2.87 k 3.3 nF 0.82 F 3.01 k 6.04 k 2 k 2 k 22 nF 100 nF 22 nF 100 nF 56 pF 510 750 k 2% 2% 1% 1% 1% 5% 1% 1% 1% 1% 1% 10 % 10 % 1% 1% 1% 1% 10% 20% 20% 20% 5% 2% 2% 100 V -- 100 V 100 V 2W 1/4 W 1/8 W 1/8 W 1/8 W 1W 1/8 W 1/10 W 1/10 W 1/10 W 1/10 W 10 V 10 V 1/8 W 1/8 W 1W 1W 100 V 100 V 100 V 100 V 100 V 2W 1/4 W
TECCOR Battrax protector TECCOR 50 ns Fusible PTC protection resistors Sense resistors
Current reference Thermal management resistors
Not Polarized Ceramic
Metallic test Longitudinal test Ceramic, not voltage sensitive Ceramic Ceramic Protector speed up capacitor Ceramic 1.2 W typ Matched to within 0.2% for initial tolerance and 0 to 70 C ambient temperature range.2 17 mW typ DPDT
CBATHi, CBATLi, CBATPi CHPi CS1i, CSSi3 RGFDi RSRBi, RSRc
Components for External Ringing
KRi
Relay
5 V Coil
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.
AM79R251
13
ELECTRICAL CHARACTERISTICS Power Dissipation
Loop resistance = 0 to unless otherwise noted (not including fuse resistors), 2 x 50 fuse resistors, BATL = -40 V, BATH = -68 V, BATP = +52 V, VCC = +5 V. For power dissipation measurements, DC-feed conditions are as follows: * * * * * ILA (Active mode current limit) = 25 mA (IRSN = 50 A) RFD (Feed resistance) = 500 VAS (Anti-sat activate voltage) = 10 V VAPP (Apparent Battery Voltage) = 48 V RTMG1 = RTMG2 (Thermal management resistors) = 1 k
Description Test Conditions On-Hook Disconnect On-Hook Standby Power Dissipation Normal Polarity On-Hook Transmission Fixed Longitudinal Voltage ISLIC Min Typ TBD TBD TBD mW TBD TBD Max Unit
On-Hook Active High Battery ISLIC Off-Hook Active Low Battery RL = 294 On-Hook Disconnect ISLIC TMG VBH VBL VCC VBH VBL VCC VBH VBL VCC VBH VBL VCC VBH VBL VCC
TBD
On-Hook Standby
TBD
Power Supply Currents
On-Hook Transmission Fixed Longitudinal Voltage On-Hook Active High Battery
TBD
mA
TBD
Off-Hook Active Low Battery RL = 294
TBD
14
AM79R251
Thermal Resistance
The junction to air thermal resistance of the AM79R251 in a 32-pin, PLCC package is 45C/W. The typical junction to case thermal resistance is 14C/W. Measured under free air convection conditions and without external heatsinking.
Absolute Maximum Ratings
Storage Temperature Ambient temperature, under bias Humidity VCC with respect to GND VBH, VBL with respect to GND VBP with respect to GND VBP with respect to VBH BGND with respect to GND Voltage on R1 relay outputs AD or BD to BGND: Continuous 10 ms (F = 0.1 Hz) 1 s (F = 0.1 Hz) 250 ns (F = 0.1 Hz) Current into SA or SB: 10 s rise to Ipeak; 1000 s fall to 0.5 Ipeak; 2000 s fall to I =0 Current into SA or SB: 2 s rise to Ipeak; 10 s fall to 0.5 Ipeak; 20 s fall to I = 0 SA SB continuous Current through AD or BD P1, P2, P3, LD to GND ESD Immunity (Human Body Model) Maximum power dissipation,1TA = 70C TA = 85C VBH - 1 to VBP + 1 VBH - 5 to VBP + 5 VBH - 10 to VBP + 10 VBH - 15 to VBP + 15 Ipeak = 5 mA Ipeak = 12.5 mA 5 mA 150 mA -0.4 to VCC + 0.4 V 1500 V min 1.67 W 1.33 W
2
-55 to +150 C -40 to +85 C TBD -0.4 to +7 V +0.4 to -85 V -0.4 to +85 V 150 V -3 to +3V +7 V
Note 1: Thermal limiting circuitry on chip will shut down the circuit at a junction temperature of about 165C. The device should never see this temperature. Operation above 145 C junction temperature may degrade device reliability. Note 2: Rise time of VBH (dv/dt) must be limited to less than 27 v/s.
Operating Ranges
Operating ranges define those limits between which device functionality is guaranteed. Functionality of the device from 0C to 70C is guaranteed by production testing. Performance from -40C to 85C is guaranteed by characterization and periodic sampling of production units. Environmental Ranges
Ambient Temperature Ambient Relative Humidity 0 to 70C Commercial -40 to +85 C extended temperature 15 to 85%
AM79R251
15
Electrical Maximum Ranges
VCC VBL VBH VBP Maximum supply voltage across device, VBP-VBH BGND with respect to GND Load resistance on VTX to Vref Load resistance on VSAB to Vref Note: Vloopmax: Vpk: 5 V 5% -(Vloopmax + 6V + Vpk) to VBH V -18 V to -79 V +79 V to +8 V 140 V -100 mV to +100 mV 20 k minimum 20 k minimum
Maximum expected loop voltage in application; ILOOP * off-hook loop resistance. Peak signal voltage for application.
16
AM79R251
SPECIFICATIONS Target Specifications (See note 1)
No. 1 Item Two-wire loop voltage (including offset) Condition Standby mode, open circuit, |VBH| < 55 V |VBH| > 55 V Any Active mode (does not include OHT), RL = 600 , IRSN = 50 A OHT mode, RL = 600 , IRSN = 36 A Standby mode Feed current Standby mode, RL = 600 Standby mode, RL = 1930 Standby mode A to VBH B to Ground Low boundary High boundary Input high current Input low current Mid-level current Input high voltage Input low voltage Input high current Input low current VREF = 1.4 V CREF = 3.3 V Tj < 145C, VSA - VSB = 22 V 0.00667 Voltage Output on IMT TBD CREF 0.3 V 45 VLB = VREF 1V ILOOP = 10 mA ILONG = 10 mA Active modes Incremental DC current gain Disconnect, ISA = 2 mA Disconnect, ISB = 2 mA TBD 300 600 1.0 500 6 12 A/A 3.0 CREF V/V V V/V mA A/A A/A A 3 3 44.6 36 43 0.6 CREF - 1 TBD TBD TBD 2.0 0.8 10 50 -50 TBD TBD +50 Min VBH - ? 13.88 Typ VBH-5 50 15 Max VBH-? 16.13 Unit V Note 3
8.64 130
10.8 250
12.96 375
2 3
Feed resistance per leg at pins AD & BD Feed current limit IMT current ILG current
30 56
mA
A
4
Ternary input voltage boundaries for LD pin. Mid-level input source must be Vref. Logic Inputs P1, P2, P3
V V A A V V V A A mV mA mA
-- -- -- -- 3
5
6 7 8 9
VTX output offset VREF input current CREF input current , DC Ratio of VAB to loop
SAB voltage: = -------------------------
3 3
V V SA - V SB
10 11 12 13 14 15 16 17 18
Fault Indicator Threshold Gain from VLB pin to A or B pin VLB pin input current ILOOP/IMT ILONG/ILG Input current, SA and SB pins K1 ISA/IMT ISB/ILG
AM79R251
17
Relay Driver Specifications
Item On Voltage Condition 25 mA/relay sink 1 relay on 3 relays on 40 mA/ relay sink 1 relay on 3 relays on R2,R3 = BGND RYE = VBH Iz = 100 A Iz = 30 mA 0 6.6 7.9 11 Min Typ 0.225 0.4 0.45 0.8 Max 0.3 0.5 0.7 1.0 100 A V V Unit Note
V
3
3
R2,R3 Off Leakage Zener Break Over, R1 Zener On Voltage, R1
Figure 5.
Relay Driver Configuration
R3
R2
RYE
Figure 5A. Ring Relay
R1
BGND
18
AM79R251
AM79R251 Transmission Specifications
No. 1 2 3 4 5 6 7 Item RSN input impedance VTX output impedance Max, AC + DC loop current Input impedance, A or B to GND 2-4 wire gain 2-4 wire gain variation with frequency 2-4 wire gain tracking Active High Battery or Active Low Battery Active mode -10 dBm, 1 kHz, 0 to 70C TA = -40C to 85C 300 to 3400 Hz, relative to 1 kHz TA=-40C to 85C +3 dBm to -55 dBm Reference: -10 dBm TA = -40 to 85C -10 dBm, 1 kHz TA= -40C to 85C 300 to 3400 Hz, relative to 1 kHz +3 dBm to -55 dBm Reference: -10 dBm 300 Hz to 3400 Hz 0 dBm 11.2 dBm -12 dBm -0.8 dBm RLOAD = 600 Active modes, RL = 600 2-wire TA = -40 to 85C 4-wire 2-wire TA = -40 to 85C 4-wire L-T 200 to 1000 Hz TA = -40C to 0C/70C to 85C 1000 to 3400 Hz TA = -40C to 0C/70C to 85C T-L Reverse Polarity 14 15 16 17 PSRR (VBH, VBL, VBP) PSRR (VCC) Longitudinal AC current per wire Metering distortion 200 to 3400 Hz L - T, IL = 0 50 to 3400 Hz L-T 200 to 1000 Hz TA = -40C to 0C/70C to 85C 50 to 3400 Hz 3.4 to 50 kHz 50 to 3400 Hz 3.4 to 50 kHz F = 15 to 60 Hz Active mode Freq = 12 kHz 2.8 Vrms Freq = 16 kHz metering load = 200 50 48 25 25 20 45 40 45 35 30 40 mArms dB 58 53 53 48 40 63 4 +7 TBD -7 -83 TBD -97 63 58 +11 dBrnC 3 -14.13 -14.18 -0.1 -0.1 TBD -0.15 -0.1 -0.1 0 TBD +0.15 +0.1 +0.1 6 70 70 -13.98 -13.98 135 -13.83 -13.78 +.1 +0.1 dB 6 Condition f = 300 to 3400 Hz Min Typ 1 3 Max Unit mA Note 3 3
8 9 10 11
4-2 wire gain 4-2 wire gain variation with frequency 4-2 wire gain tracking Total harmonic distortion level 2-wire 4-wire 4-wire overload level at VTX
-50 -40 -48 -38 1
dB dB dB dB Vp
3
12
Idle channel noise C-message Weighted Psophometric Weighted
-79
dBmp 3
13
Longitudinal balance (IEEE method) Normal Polarity
dB 4, 5 2, 3, 5 4, 5 2, 3, 5 3 3
AM79R251
19
AM79R251 Ringing Specifications
Item Peak Ringing Voltage Condition Active Internal Ringing Min VBH+5 Typ Max VBP-5 Unit V Note 8
AM79R251 Current-Limit Behavior
SLIC Mode Disconnect Tip Open Standby Active Ringing Condition Applied fault between ground and T/R VBH applied to Tip or Ring Short to GND Short Tip-to-VBH Short Ring-to-GND ISLAC generating internal ringing Min Typ 1 VBH/200K 30 30 30 100 mA Max 100 Unit A A Note 7
AM79R251 Fault Indications
Fault No Fault Thermal Shutdown Indication IMT operates normally (Vref 1V) IMT above 2.8 V; ILG operates normally Unit Note
Notes: 1. Unless otherwise specified, test conditions are: VCC = 5 V, RMG1 = RMG2 = 1 k, BATH = -68 V, BATL = -40 V, BATP = +52 V, RRX = 150 k, RL = 600 , RSA = RSB = 200 k, RFA = RFB = 50 , CHP = 22 nF, CAD = CBD = 22 nF, IRSN = 50 A. DC-feed conditions are normally set by the ISLAC device. When the AM79R251 is tested by itself, its operating conditions must be simulated as if it were connected to an ideal ISLAC device.
30 K RT Network
30 K
390 pf VREF
2. These tests are performed with the following load impedances: Frequency < 12 kHz - Longitudinal impedance = 500 ; metallic impedance = 300 Frequency > 12 kHz - Longitudinal impedance = 90 ; metallic impedance = 135 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 AM79R251 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. 8. Other ringing-voltage characteristics are set by the ISLAC device.
20
AM79R251
Operating Modes
The AM79R251 receives multiplexed control data on the P1, P2 and P3 pins. The LD pin then controls the loading of P1, P2, and P3 values into the proper bits in the AM79R251 control register. When the LD pin is less than 0.3 V below VREF ( < (VREF - 0.3 V) ), P1-P3 must contain data for relay control bits RD1, RD2 and RD3. These are latched into the first three bits in the AM79R251 control register. When the LD pin is more than 0.3 V above VREF (> (VREF + 0.3 V) ), P1-P3 must contain ISLIC control data C1, C2, and C3, which are latched into the last three bits of the AM79R251 control register. Connecting the LD pin to VREF locks the contents of the AM79R251 control register. The operating mode of the AM79R251 is determined by the C1, C2, and C3 bits in the control register of the AM79R251. Table 1 defines the AM79R251 operating modes set by these signals. Under normal operating conditions, the ISLIC device does not have active relays. The AM79R251 to ISLAC device interface is designed to allow continuous real-time control of the relay drivers to avoid incorrect data loads to the relay bit latches of the AM79R251 devices. To perform external ringing, the ISLAC device from the Intelligent Access voice family is set to external ringing mode (RMODE = 1), enables the ring relay, and puts the AM79R251 in the Standby mode. Table 1. Operating Modes Connection to RMGPi & RMGLi Resistors
Open
C3
C2
C1
Operating Mode
Standby1
Battery Voltage Selection
High Battery (BATH) and BGND High Battery (BATH) and BGND High Battery (BATH) and BGND
Operating Mode
0
0
0
(High ohmic feed): Loop supervision active, A and B amplifiers shut down Tip Open: AD at High-Impedance, Channel A power amplifier shut down Fixed longitudinal voltage of -30 V
0
0
1
Tip Open1
Open
0
1
0
On-Hook Transmission, Fixed Longitudinal Voltage Disconnect
0
1
1
Low Battery selection at VBL High Battery (BATH) and Positive Battery (BATP) High Battery (BATH) and BGND Low Battery (BATL) and BGND High Battery (BATH) and Positive Battery (BATP)
AD and BD at High-Impedance, Channel A and B power amplifiers shut down A and B Amplifier Output Active feed, normal or reverse polarity
1
0
0
Active Boosted Battery Active High Battery Active Low Battery Active Internal Ringing
1 1 1
0 1 1
1 0 1
Active internal ringing
Note: 1. In these modes, the ring lead (B-lead) output has a -50 V internal clamp to battery ground (BGND).
AM79R251
21
Table 2.
Mode Descriptions Operating Mode
Disconnect
Description
This mode disconnects both A and B output amplifiers from the AD and BD outputs. The A and B amplifiers are shut down and the AM79R251 selects the low battery voltage at the VBL pin. In the Disconnect state, the currents on IMT and ILG represent the voltages on the SA and SB pins, respectively. These currents are scaled to produce voltages across
SA SB RMTi and RLGi of --------- and --------- , respectively.
V 400
V 400
Standby
The power amplifiers are turned off. The AD output is driven by an internal 250 (typical) resistor, which connects to ground. The BD output is driven by an internal 250 (typical) resistor, which connects to the high battery (BATH) at the VBH pin, through a clamp circuit, which clamps at -50 V with respect to BGND. For VBH values above-55 V, the opencircuit voltage, which appears at this output is ~VBH + 5 V. If VBH is below -55 V, the voltage at this output is -50 V. The battery selection for the balance of the circuitry on the chip is VBL. Line supervision remains active. Current limiting is provided on each line to limit power dissipation under short-loop conditions as specified in the "AM79R251 CurrentLimit Behavior" section. In external ringing, the standby ISLIC state is selected. In this mode, the AD (Tip) lead is opened and the BD (Ring) lead is connected to a clamp, which operates from the high battery on VBH pin and clamps to approximately -50 V with respect to BGND through a resistor of approximately 250 (typical). The battery selection for the balance of the circuitry on the chip is VBL. To prevent excessive power dissipation, the current in the Ring lead is limited by an internal current source to 30 mA. In the Active High Battery mode, battery connections are connected as shown in Table 1. Both output amplifiers deliver the full power level determined by the programmed DC-feed conditions. Active High Battery mode is enabled during a call in applications when a long loop can be encountered. Both output amplifiers deliver the full power level determined by the programmed DC-feed conditions. VBL, the low negative battery, is selected in the Active Low Battery mode. This is typically used during the voice part of a call. In the Active Boosted Battery mode, battery connections are as shown in Table 1. Both output amplifiers deliver the full power level determined by the programmed DC-feed conditions. Active Boosted Battery mode is enabled during a call in applications when an extended loop can be encountered. In the Internal Ringing mode, the AM79R251 selects the battery connections as shown in Table 1. When using internal ringing, both the AD and BD output amplifiers deliver the ringing signal determined by the programmed ringing level. In the On-Hook Transmission, Fixed Longitudinal Voltage mode, battery connections are as shown in Table 1. The longitudinal voltage is fixed at -30 V to allow compliance with safety specifications for some classes of products.
Tip Open
Active High Battery
Active Low Battery Active Boosted Battery
Active Internal Ringing On-Hook Transmission (OHT), Fixed Longitudinal Voltage
22
AM79R251
Control bits RD1, RD2, and RD3 do not affect the operating mode of the AM79R251. These signals usually perform the following functions. Table 3. Driver Descriptions Driver
R1 R2
Description
A logic 1 on RD1 turns the R1 driver on and operates a relay connected between the R1 pin and VCCD. R1 drives the ring relay when external ringing is selected. A logic 1 on the RD2 signal turns the R2 driver on and routes current from the R2 pin to the RYE pin. In the option where the RYE pin is connected to ground, the R2 pin can sink current from a relay connected to VCCD. Another option is to connect the RYE pin to the BD (Ring) lead and connect a test load between R2 and the AD(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 AM79R251 side of the protection resistor to avoid damage to the R2 driver. 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 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 AM79R251 side of the protection resistor to avoid damage to the R3 driver.
R3
Thermal-Management Equations (All Modes except Standby)
IL < 5 mA PSLIC = (SBAT - ILRL) * IL + 0.3 W PTMG = 0 IL > 5 mA PSLIC = (SBAT - IL(RL + 2 * RFUSE))*IL + 0.3 W - PTMG PTMG = (IL - 5 mA)^2 * (RTMG1 + RTMG2) 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 AM79R251. These equations are valid when RTMGX * (IL - 5 mA) < (SBAT - RLIL)/2 - 2 because the longitudinal voltage is one-half the battery voltage and the TMG switches require approximately 2 V.
AM79R251
23
TIMING SPECIFICATIONS
Symbol
trSLD tfSLD tSLDPW tSDXSU tSDXHD tSDXD
Signal
LD LD LD P1,P2,P3 P1,P2,P3 P1,P2,P3
Parameter
Rise time AM79R251 LD pin Fall time AM79R251 LD pin LD minimum pulse width P1-3 data Setup time P1-3 data hold time Max P1-3 data delay
Min
Typ
Max
2 2
Unit
3 4.5 4.5 5
s
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 AM79R251 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. AM79R251 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 AM79R251 and the line connection. 6. Not tested in production. Guaranteed by characterization.
24
AM79R251
WAVEFORMS
VCC LD VREF 0V Write State Register Lock Registers Write Relay Register
Previous P1,P2,P3 Relay Data
Relay Data
State Data
New Relay Data
DETAIL A
VREF
LD
trSLD
Write State Register
tfSLD
VREF
Write Relay Register
tSLDPW
tSDXSU
tSDXHD
P1,P2,P3
AM79R251
25
PHYSICAL DIMENSIONS PL032
.447 .453 .485 .495 .009 .015 .125 .140 .080 .095 SEATING PLANE .400 REF. .013 .021 .026 .032 TOP VIEW .050 REF. .490 .530 .042 .056
.585 .595 .547 .553
Pin 1 I.D.
SIDE VIEW
16-038FPO-5 PL 032 DA79 6-28-94 ae
REVISION SUMMARY Revision A to Revision B * Revision A was a condensed version of the datasheet while Revision B contains the full version. Revision B to Revision C * Page 13, Linecard Parts List, Rows CHLbi and CHLdi: switched the numbers in the "Values" column.
26
AM79R251
The contents of this document are provided in connection with Advanced Micro Devices, Inc. ("AMD") products. AMD makes no representations or warranties with respect to the accuracy or completeness of the contents of this publication and reserves the right to make changes to specifications and product descriptions at any time without notice. No license, whether express, implied, arising by estoppel or otherwise, to any intellectual property rights is granted by this publication. Except as set forth in AMD's Standard Terms and Conditions of Sale, AMD assumes no liability whatsoever, and disclaims any express or implied warranty, relating to its products including, but not limited to, the implied warranty of merchantability, fitness for a particular purpose, or infringement of any intellectual property right. AMD's products are not designed, intended, authorized or warranted for use as components in systems intended for surgical implant into the body, or in other applications intended to support or sustain life, or in any other application in which the failure of AMD's product could create a situation where personal injury, death, or severe property or environmental damage may occur. AMD reserves the right to discontinue or make changes to its products at any time without notice.
(c) 1999 Advanced Micro Devices, Inc. All rights reserved.
Trademarks AMD, the AMD logo and combinations thereof are trademarks of Advanced Micro Devices, Inc. Intelligent Access and WinSLAC are trademarks of Advanced Micro Devices, Inc. Product names used in this publication are for identification purposes only and may be trademarks of their respective companies.

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