™
A
Quad Intelligent Subscriber Line Audio-processing Circuit
VE790 Series
Voice Solution
ORDERING INFORMATION
Device
Le79Q2281DVC
Le79Q2284MVC
1.
Package
1
64-pin TQFP
(Green)
80-pin LQFP
(Green)
Tray
Tray
Packing
2
Le79228
APPLICATIONS
Voice over IP/DSL
—
Integrated Access Devices (IAD),
Smart Residential Gateways (SRG), Home Gateway/
Router
Cable Telephony
— NIU, Set-Top Box, Home Side
Box, Cable Modem, Cable PC
Fiber
— Fiber in the Loop (FITL), Fiber to the
Home (FTTH)
Wireless Local Loop, Intelligent PBX
DLC-MUX
CO
The green package meets RoHS Directive 2002/95/EC of the
European Council to minimize the environmental impact of
electrical equipment.
For delivery using a tape and reel packing system, add a "T" suffix
to the OPN (Ordering Part Number) when placing an order.
2.
DESCRIPTION
The Le79228 Quad Intelligent Subscriber Line Audio-
processing Circuit (ISLAC™) device, in combination with a
VE790 series ISLIC™ device, implements a four-channel
universal telephone line interface. This enables the design of a
s i n g l e , l o w c o s t , h i g h p e r f o r m a n c e , f u l l y s o ft w a r e
programmable line interface for multiple country applications.
All AC, DC, and signaling parameters are fully programmable
via microprocessor or GCI interfaces. Additionally, the
Le79228 Quad ISLAC 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.
FEATURES
High performance digital signal processor provides
programmable control of all major line card functions
— A-law/µ-law and linear codec/filter
– Transmit and receive gain
– Two-wire AC impedance
– Transhybrid balance
– Equalization
— DC loop feeding
– Smooth or abrupt polarity reversal
— Loop supervision
– Off-hook debounce circuit
– Ground-key and ring-trip filters
— Internal ringing generation and integrated ring-trip
detection
— Adaptive hybrid balance
— Line and circuit testing
– Meets GR-909 and GR-844 test requirements
— Tone generation (DTMF, FSK, random noise, and
arbitrary tone)
— Metering generation at 12 kHz and 16 kHz
– Envelope shaping and level control
— Modem Tone Detection
Selectable PCM/MPI or GCI digital interfaces
— Supports most available master clock frequencies from
512 kHz to 8.192 MHz
General purpose I/O pins
+3.3 V DC operation
Exceeds LSSGR and ITU requirements
Supports external ringing with on-chip ring-trip circuit
— Automatic or manual ring-trip modes
Supports CallerNumber Identification (CID) tone
generation
RELATED LITERATURE
081237 Le79232 Dual ISLIC™ Device Data Sheet
081152 Le79242 Dual ISLIC™ Device Data Sheet
081185 Le79252 Dual ISLIC™ Device Data Sheet
081191 Le75282 Dual LCAS Device Data Sheet
080923 Le792x2 Le79228 Chip Set User’s Guide
081151 Le79112 VCP Device Data Sheet
BLOCK DIAGRAM
4
14
VCCA
VCCD
A1
B1
Dual ISLIC
A2
B2
A3
B3
Dual ISLIC
A4
B4
P1-P3
LD3
LD4
RREF
4
LD1
2
LD2
VREF
4
2
DGND
Protection
and LCAS or
EMR for
External Ringing
AGND
14
I/O1 - I/O4
TSCA/G
TSCB
DRA/DD
DRB
Quad ISLAC
DXB
DXA/DU
DCLK/S0
PCLK/FS
MCLK
External
Ringing
Sense
Resistors
5
RSHB
BATH
RSLB
BATL
RSPB
BATP
FS/DCL
CS/RST
DIO/S1
INT
NOTE: On August 3, 2007, Zarlink Semiconductor acquired the products and
technology of Legerity Holdings.
Document ID#
081256
Date:
Sep 19, 2007
Rev:
G
Version:
2
Distribution:
Protected Document
Le79228
TABLE OF CONTENTS
Data Sheet
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Related Literature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Product Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Optional VCP Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Le79228 Quad ISLAC™ Device Internal Block Diagram (80-Pin LQFP) . . . . . . . . . . . . . . . . . . . .5
Features of the Le79228 Quad ISLAC™ Chip Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Connection Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Operating Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
DC Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Transmission Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Transmit and Receive Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Attenuation Distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Group Delay Distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Single Frequency Distortion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Gain Linearity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Total Distortion Including Quantizing Distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Overload Compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Discrimination Against Out-of-Band Input Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Spurious Out-of-Band Signals at the Analog Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Switching Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Microprocessor Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
PCM Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
GCI Timing Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
ISLIC Device Timing Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Application Circuits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Line card Parts List- INTERNAL RINGING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Line card Parts List - EXTERNAL RINGING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Physical Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
64-Pin Thin Quad Flat Pack (TQFP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
80-Pin Low-Profile Quad Flat Pack (LQFP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Revision A1 to B1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Revision B1 to C1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Revision C1 to D1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Revision D1 to E1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Revision E1 to F1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Revision F1 to G1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Revision G1 to G2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
2
Zarlink Semiconductor Inc.
Le79228
PRODUCT DESCRIPTION
Data Sheet
The VE790 series voice chip sets integrate all functions of the subscriber line for four subscriber lines. One or more of two chip
types are used to implement the line card; a VE790 series ISLIC device and a Le79228 Quad ISLAC device. These provide the
following basic functions:
The VE790 series ISLIC device: A high voltage, bipolar IC that drives the subscriber line, maintains longitudinal balance and
senses line conditions.
2. The Le79228 Quad ISLAC device: A low voltage CMOS IC that provides conversion and DSP functions for all four channels.
Complete schematics of line cards using the Le79228 Quad ISLAC device for internal and external ringing are shown in
Application Circuits,
on page 28.
The VE790 series ISLIC device uses reliable, bipolar technology to provide the power necessary to drive a wide variety of
subscriber lines. It can be programmed by the Quad 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 VE790 series ISLIC device is
designed to be used exclusively with the Le79228 Quad ISLAC device as part of a multiple-line chip set.
The VE790 series ISLIC device implements a linear loop-current feeding method with the enhancement of intelligent thermal
management in a controlled manner. This limits the amount of power dissipated on the VE790 series ISLIC chip by dissipating
excess power in external resistors.
Each Le79228 Quad ISLAC device contains high-performance analog circuits that provide A/D and D/A conversion for voice
(codec/filter), DC-feed and supervision signals for four subscriber channels. The Le79228 Quad ISLAC device contains a DSP
core that handles signaling, DC-feed, supervision and line diagnostics for all four 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 Le79228 Quad ISLAC device 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 chip sets provide system level solutions for the loop supervisory functions and metering. In total, they provide a
programmable solution that can satisfy worldwide line card 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 and allows the designer to enter a description of system requirements. WinSLAC
then computes the necessary coefficients and plots the predicted system results.
The VE790 series ISLIC device interface unit inside the Le79228 Quad ISLAC device processes information regarding the line
voltages, loop currents and battery voltage levels. These inputs allow the Le79228 Quad ISLAC device to place several key
VE790 series ISLIC device performance parameters under software control.
The main functions that can be observed and/or controlled through the Le79228 Quad ISLAC device 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 reversal
•
Subscriber line matching
•
Ringing generation
•
Sophisticated line and circuit tests
To accomplish these functions, the VE790 series ISLIC device collects the following information and feeds it, in analog form, to
the Le79228 Quad ISLAC device:
•
•
The metallic (IMT) and longitudinal (ILG) loop currents
The AC (VTX) and DC (VSAB) loop voltages
1.
The outputs supplied by the Le79228 Quad ISLAC device to the VE790 series ISLIC device are then:
•
•
A voltage (VHL
i
*) that provides control for the following high-level VE790 series ISLIC device outputs:
DC loop current
3
Zarlink Semiconductor Inc.
Le79228
•
•
•
•
Internal ringing signal
12- or 16-kHz metering signal
A low-level voltage proportional to the voice signal (VOUT
i
)
A voltage that controls longitudinal offset for test purposes (VLB
i
)
Data Sheet
The Le79228 Quad 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. 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/filter functions, the Le79228 Quad ISLAC device provides all the sensing, feedback, and clocking necessary
to completely control VE790 series ISLIC device functions with programmable parameters. System-level parameters under
programmable control include active loop current limits, feed resistance, and feed mode voltages.
The Le79228 Quad ISLAC device supplies complete mode control to the VE790 series ISLIC device using the control bus and
(P1-P3) tri-level load signal (LD
i
).
The Le79228 Quad ISLAC device 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 PCM measurement
data directly to a higher level processor by way of the voice channel. Both longitudinal and metallic resistance and capacitance
can be measured, which allows leakage resistance, line capacitance, and telephones to be identified.
*Note:
"i" denotes channel number
OPTIONAL VCP FEATURES
Optional Voice Control Processor (VCP) features provide the following solutions to the VE790 series intelligent chip sets:
•
•
•
Integrated test software routines
DTMF detection
Aggregated codec/filter control
4
Zarlink Semiconductor Inc.
Le79228
Le79228 Quad ISLAC™ Device Internal Block Diagram (80-Pin LQFP)
IREF VREF
VHL1
VLB1
VOUT1
VIN1
VSAB1
VIMT1
VILG1
GS1
GS2
XSB1
Ch 1
Converter
Block
Clock and
Reference
Circuits
PCM
and
GCI
Interface
and
Time Slot
Assigner
MCLK
Data Sheet
FS/DCL
PCLK/FS
DXA/DU
DRA/DD
TSCA/G
DXB
DRB
TSCB
DCLK/S0
DIN/S1
Ch 2
(Same as Ch 1)
Digital
Signal
Processor
GCI Control
Logic and
Microprocessor
Interface
DOUT
CS/RST
INT
I/O1
I/O2
I/O3
I/O4
LD1
LD2
LD3
LD4
P1
P2
P3
XSC
SHB
SLB
SPB
Ch 3
(Same as Ch 1)
Ch 4
(Same as Ch 1)
790 Series SLIC
Control
Logic
Common
External
Sense
Inputs
5
Zarlink Semiconductor Inc.
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