TM
Document ID# 080249
Date:
Dec 5 2005
Rev:
O
Version: 1
Distribution:
Public Document
Le79R241
Intelligent Subscriber Line Interface Circuit
VE790 Series
APPLICATIONS
Enables a cost effective voice solution for long or short
loop applications providing POTS and integrated test
capabilities
-- CO
-- DLC
-- PBX/KTS
-- Pair gain
FEATURES
Monitor of two-wire interface voltages and currents
supports
-- Voice transmission
-- Internal 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
Supports internal short loop or external ringing
+5 V and battery supplies
Dual battery operation for system power saving
-- Automatic battery switching
-- Intelligent thermal management
Compatible with inexpensive protection networks
-- Accommodates low tolerance fuse resistors or PTC
thermistors
Metering capable
-- 12 kHz and 16 kHz
-- Smooth polarity reversal
Tip-open state supports ground start signaling
Integrated test load switches/relay drivers
5 REN with DC offset trapezoid.
-- For US standard:
-- drives ring up to 4.4 kft of 26 gauge wire.
-- drives ring up to 7 kft of 24 gauge wire.
-- For European (British) standard:
-- drives ring up to 1.7 km of 0.5 mm copper cable.
Space Saving Package Options (8x8 QFN)
ORDERING INFORMATION
A VE790 series ISLACTM device must be used with this part.
1.
Due to size constraints, QFN devices are marked by omitting the
"Le" prefix and the performance grade dash character. For
example, Le79R241QC is marked 79R241QC.
2.
The green package meets RoHS Directive 2002/95/EC of the
European Council to minimize the environmental impact of
electrical equipment.
3.
For delivery using a tape and reel packing system, add a "T" suffix
to the OPN (Ordering Part Number) when placing an order.
Device
Package Type
1, 2
Packing
3
Le79R241JC
32-pin PLCC
Tube
Le79R241DJC
32-pin PLCC (Green)
Le79R241QC
32-pin QFN
Tray
Le79R241FQC
32-pin QFN (Green)
DESCRIPTION
The Le79R241 Intelligent Subscriber Line Interface Circuit
(ISLICTM) device, in combination with a VE790 series 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 VE790 series ISLAC device. Additionally, the Le79R241
ISLIC 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.
RELATED LITERATURE
080248 Le79231 ISLICTM Device Data Sheet
080253 Le79R251 ISLICTM Device Data Sheet
080250 Le79Q224x Quad ISLACTM Device Data Sheet
081065 Le79228 Quad ISLACTM Device Data Sheet
080262 VE790 Series Evaluation Board User's Guide
080804 Le79R2xx/Le79Q224x Chip Set User's Guide
080923 Le79R2xx/Le79228 Chip Set User's Guide
081103 Le79610 PacketSLACTM Device Data Sheet
2
Le79R241 VE790 Series Data Sheet
TABLE OF CONTENTS
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Ordering Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Related Literature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Product Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Le79R241 ISLICTM Device Internal Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Features of the VE790 series Chip set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Chip set Block Diagram - Four Channel Line card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Connection Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Thermal Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Operating Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
DC Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Relay Driver Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Transmission Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Ringing Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Current-Limit Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Thermal Shutdown Fault Indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Operating Mode Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Driver Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Thermal-Management Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Timing Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Application Circuits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Line card Parts List- Internal Ringing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Line card Parts List - External Ringing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Physical Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
32-Pin PLCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
32-Pin QFN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Revision H to Revision I. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Revision I to Revision J . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Revision J to K. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Revision K to L. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Revision L to M1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Revision M1 to N1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Revision N1 to O1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Le79R241 VE790 Series Data Sheet
3
PRODUCT DESCRIPTION
Legerity's VE790 series voice chip sets integrate all functions of the subscriber line. Two chip types are used to implement the
line card
--
the Le79R241 ISLIC device and a VE790 series ISLAC device. These provide the following basic functions:
1. The Le79R241 ISLIC device: A high voltage, bipolar device that drives the subscriber line, maintains lon-
gitudinal balance and senses line conditions.
2. The VE790 series ISLAC devices: Low voltage CMOS ICs that provide conversion, control and DSP func-
tions for the Le79R241 ISLIC device.
A complete schematic of the line card using a VoiceEdge chip set for internal and external ringing is shown in
Application Circuits,
on page 19
.
The Le79R241 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 VE790 series 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 Le79R241 ISLIC device is designed
to be used exclusively with the VE790 series ISLAC devices. The Le79R241 ISLIC device requires only +5 V power and the
battery supplies for its operation.
The Le79R241 ISLIC device implements a linear loop-current feeding method with the enhancement of intelligent thermal
management. This limits the amount of power dissipated on the Le79R241 ISLIC device by dissipating power in external resistors
in a controlled manner.
Each codec contains high-performance circuits that provide A/D and D/A conversion for the voice (codec), DC-feed and
supervision signals. The VE790 series ISLAC devices contain 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 790 series voice chip set 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 WinSLACTM 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 Le79R241 ISLIC device interface unit inside the VE790 series ISLAC device processes information regarding the line
voltages, loop currents and battery voltage levels. These inputs allow the VE790 series ISLAC device to place several key
Le79R241 ISLIC device performance parameters under software control.
The main functions that can be observed and/or controlled through the VE790 series 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 battery reversal
Subscriber line matching
Ringing generation
Sophisticated line and circuit tests
To accomplish these functions, the Le79R241 ISLIC device collects the following information and feeds it, in analog form, to the
VE790 series ISLAC device:
The metallic (IMT) and longitudinal (ILG) loop currents
The AC (VTX) and DC (VSAB) loop voltage
The outputs supplied by the VE790 series ISLAC devices to the Le79R241 ISLIC device are then:
A voltage (VHL
i
*) that provides control for the following high-level Le79R241 ISLIC device outputs:
4
Le79R241 VE790 Series Data Sheet
DC loop current
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
)
The VE790 series ISLAC devices perform 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 790 series voice chip set provides all the sensing, feedback, and clocking necessary to
completely control Le79R241 ISLIC device functions with programmable parameters. System-level parameters under
programmable control include active loop current limits, feed resistance, and feed mode voltages.
The VE790 series ISLAC devices supply complete mode control to the Le79R241 ISLIC device using the control bus (P1-P3)
and tri-level load signal (LD
i
).
The 790 series voice chip set 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 measured, which allows leakage resistance, line capacitance, and telephones to be identified.
*Note:
i = channel number
Figure 1. Block Diagram
Two-Wire
Interface
Thermal
Management
Control
Signal
Transmission
Gain/Level
Shift
Attenuator
Longitudinal
Control
Signal
Conditioning
Fault
Meas.
Input Decoder and
Control Registers
Switch Driver
Relay
Drivers
Relay
Driver 1
BGND
GND
VCC
Relay
Control
RSN
VTX
VLB
VSAB
VREF
IMT
ILG
CREF
P2
P3
P1
LD
AD
SA
HPA
HPB
SB
BD
TMN
TMP
TMS
VBL
R3
RYE
R2
R1
VBH
Le79R241 VE790 Series Data Sheet
5
LE79R241 ISLICTM DEVICE INTERNAL BLOCK DIAGRAM
AD
BD
SA
SB
RSN
VLB
IMT
ILG
+
-
+
-
=
0.01
+
-
+
-
+
-
+
VTX
HPA
HPB
VBH
VREF
IA sense
IB sense
VREF
VBL
LD
VCC
GND
Active Lo
w Batter
y
VREF
TMN
Thermal
Management
Control
BGND
VSAB
Decoder
Standb
y
OHT Fix
ed Longitudinal
V
olta
g
e
TMP
VREF
IB
600
IB
Demux
RD2
RD3
C1
C2
C3
RD1
Control Register
P1
P2
P3
Reser
ved
Gain/Level Shift
IA
600
TMS
Active High Batter
y
High Neg.
Bat. sel.
R1
R3
RYE
R2
Power amplifiers positive supply
BGND
To Power
Amplifiers
Tip Open
CREF
Thermal
Shutdown
Disconnect
Fault
Meas.
Fault
Meas.
IA
600
IB
600
+
IA
IB
600
600
-
IA
A Amplifier
B Amplifier
6
Le79R241 VE790 Series Data Sheet
FEATURES OF THE VE790 SERIES CHIP SET
Performs all battery feed, ringing, signaling, hybrid and
test (BORSCHT) functions
Two chip solution supports high density, multi-channel
architecture
Single hardware design meets multiple country require-
ments 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
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 man-
ual or automatic ring-trip mode
Supports metering generation with envelope shaping
Smooth or abrupt polarity reversal
Adaptive transhybrid balance
Continuous or adapt and freeze
Supports both loop-start and ground-start signaling
Exceeds LSSGR and CCITT central office requirements
Selectable PCM or GCI interface
Supports most available master clock frequencies
from 512 kHz to 8.192 MHz
On-hook transmission
Power/service denial mode
Line-feed characteristics independent of battery voltage
Only 5 V, 3.3 V and battery supplies needed
Low idle-power per line
Linear power-feed with intelligent power-management
feature
Compatible with inexpensive protection networks;
Accommodates low-tolerance fuse resistors while main-
taining longitudinal balance
Monitors two-wire interface voltages and currents for
subscriber line diagnostics
Built-in voice-path test modes
Power-cross, fault, and foreign voltage detection
Integrated line-test features
Leakage
Line and ringer capacitance
Loop resistance
Integrated self-test features
Echo gain, distortion, and noise
Guaranteed performance over commercial and industrial
temperature ranges.
Up to three relay drivers per Le79R241 ISLIC device
Configurable as test load switches
Le79R241 VE790 Series Data Sheet
7
CHIP SET BLOCK DIAGRAM - FOUR CHANNEL LINE CARD
RC
Networks
and
Protection
A1
B1
B3
A3
B2
A2
A4
B4
VCCA
Le79Q224x
Quad Codec/
Filter
Le79R241
Le79R241
Le79R241
Le79R241
LD1
VREF
LD2
LD3
LD4
P1-P3
AGND1
AGND2
VCCD
DXA/DU
DRB
DRA/DD
IO(1-4)
DGND2
DGND1
DXB
DCLK/S0
PCLK/FS
MCLK
FS/DCL
DIO/S1
INT
TSCA/G
TSCB
CS/RST
BATH
3
7
7
7
7
4
4
R
REF
R
SHB
BATL
R
SLB
8
Le79R241 VE790 Series Data Sheet
CONNECTION DIAGRAMS
Figure 2. Le79R241DJC
Figure 3. Le79R241FQC
1.
Pin 1 is marked for orientation.
2.
RSVD = Reserved. Do not connect to this pin.
3.
The thermally enhanced QFN package features an exposed pad on the underside which must be electrically tied to VBH.
HPB
VBH
VCC
BGND
BD
AD
RSVD
4
3
2
1
32
31
30
29
28
27
26
25
24
23
22
21
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
LD
VSAB
VLB
GND
RSN
VREF
SB
SA
IMT
ILG
RSVD
HPA
VTX
P2
P1
TMN
TMS
TMP
RYE
R2
R1
32-Pin PLCC
P3
CREF
VBL
R3
Exposed Pad
1
32-Pin QFN
21
20
19
18
17
22
23
24
2
3
4
5
6
7
8
10
9
12
11
14
13
16
15
32
31
30
29
28
27
26
25
P2
P3
LD
VREF
GND
RSN
VSAB
VLB
TMP
TMN
P1
R1
R2
RYE
R3
TMS
VTX
HPA
HPB
RSVD
CREF
ILG
IMT
SA
SB
AD
RSVD
BD
VCC
BGND
VBH
VBL
Le79R241 VE790 Series Data Sheet
9
PIN DESCRIPTIONS
Pin Name
Type
Description
AD, BD
Output
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 Le79R241 ISLIC device
to codec interface.
GND
Ground
Analog and digital ground return for VCC.
HPA, HPB
Output
These pins connect to CHP, the external high-pass filter capacitor that separates the DC
loop-voltage from the voice transmission path.
ILG
Output
ILG is proportional to the common-mode line current (IADIBD), except in disconnect
mode, where ILG is proportional to the current into grounded SB.
IMT
Output
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 Le79R241 ISLIC device
indicates thermal overload by pulling IMT to CREF.
LD
Input
The LD pin controls the input latch and responds to a 3-level input. When the LD pin is a
logic 1 (C
REF
- 1), the logic levels on P1P3 latch into the Le79241 control register bits that
operate the mode-decoder. When the LD pin is a logic 0 (
< 0.6), the logic levels on P1P3
latch into the Am79241 control register bits that control the relay drivers (RD1RD3). When
the LD pin level is at ~V
REF
0.3 V, the control register contents are locked.
P1P3
Input
Inputs to the latch for the operating-mode decoder and the relay-drivers.
R1
Output
Collector connection for relay 1 driver. Emitter internally connected to BGND.
R2
Output
Collector connection for relay 2 driver. Emitter internally connected to RYE
R3
Output
Collector connection for relay 3 driver. Emitter internally connected to RYE.
RSN
Input
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
These pins are used during Legerity testing. In the application, they must be left floating.
RYE
Output
Emitter connection for R2 and R3. Normally connected to relay ground.
SA, SB
Input
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
Output
External resistors connected from TMP to TMS and TMN to VBL to offload excess power
from the Le79R241 ISLIC device.
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 Le79R241 ISLIC device.
VLB
Input
Sets the DC longitudinal voltage of the Le79R241 ISLIC device. It is the reference for the
longitudinal control loop. When the VLB pin is greater than VREF, the Le79R241 ISLIC
device 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
Input
The VE790 series SLAC device provides this voltage which is used by the Le79R241 ISLIC
device for internal reference purposes. All analog input and output signals interfacing to the
VE790 series SLAC device are referenced to this pin.
VSAB
Output
Scaled-down version of the voltage between the sense points SA and SB on this pin.
VTX
Output
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.
Exposed
Pad
Battery
This must be electrically tied to VBH.
10
Le79R241 VE790 Series Data Sheet
ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings
Stresses greater than those listed under Absolute Maximum Ratings can cause permanent device failure. Functionality at or
above these limits is not implied. Exposure to absolute maximum ratings for extended periods can affect device reliability
Note:
1.
Thermal limiting circuitry on chip will shut down the circuit at a junction temperature of about 165C. Operation above 145C junction
temperature may degrade device reliability.
The thermal performance of a thermally enhanced package is assured through optimized printed circuit board layout. Specified performance
requires that the exposed thermal pad be soldered to an equally sized exposed copper surface, which, in turn, conducts heat through mul-
tiple vias to a large internal copper plane.
2.
Rise time of VBH (dv/dt) must be limited to less than 27 v/ms.
Thermal Resistance
The junction to air thermal resistance of the Le79R241 ISLIC device in a 32-pin PLCC package is 45 C/W and in a 32-pin QFN
package is 25 C/W (measured under free air convection conditions and without external heat sinking).
Package Assembly
The standard (non-green) package devices are assembled with industry-standard mold compounds, and the leads possess a tin/
lead (Sn/Pb) plating. These packages are compatible with conventional SnPb eutectic solder board assembly processes. The
peak soldering temperature should not exceed 225C during printed circuit board assembly.
Green package devices are assembled with enhanced, environmental compatible lead-free, halogen-free, and antimony-free
materials. The leads possess a matte-tin plating which is compatible with conventional board assembly processes or newer lead-
free board assembly processes. The peak soldering temperature should not exceed 245C during printed circuit board assembly.
Refer to IPC/JEDEC J-Std-020B Table 5-2 for the recommended solder reflow temperature profile.
Storage temperature
55 to +150C
Ambient temperature, under bias
40 to +85C
Humidity
5% to 95%
VCC with respect to GND
0.4 to +7 V
VBH, VBL with respect to GND (See note 2)
+0.4 to 104 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 s (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 s rise to Ipeak
1000 s fall to 0.5 Ipeak;
2000 s fall to I =0
Ipeak = 5 mA
Current into SA or SB:
2 s rise to Ipeak
10 s fall to 0.5 Ipeak;
20 s 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
Maximum power dissipation (see note 1)
T
A
= 70 C
In 32-pin PLCC package
1.67 W
In 32-pin QFN package
3.00 W
T
A
= 85 C
In 32-pin PLCC package
1.33 W
In 32-pin QFN package
2.40 W
ESD Immunity (Human Body Model)
JESD22 Class 1C compliant
Le79R241 VE790 Series Data Sheet
11
Operating Ranges
Legerity guarantees the performance of this device over commercial (0C to 70C) and industrial (-40C to 85C) temperature
ranges by conducting electrical characterization over each range and by conducting a production test with single insertion
coupled to periodic sampling. These characterization and test procedures comply with section 4.6.2 of Bellcore GR-357-CORE
Component Reliability Assurance Requirements for Telecommunications Equipment.
Environmental Ranges
Electrical Ranges
SPECIFICATIONS
Power Dissipation
Loop resistance = 0 to
unless otherwise noted (not including fuse resistors), 2 x 50 fuse resistors, BATL = 36 V,
BATH = 90 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
RMGLi = RMGPi (Thermal management resistors) = 1 k
Ambient Temperature
0 to 70C Commercial
40 to +85 C extended temperature
Ambient Relative Humidity
15 to 85%
VCC
5 V 5%
VBL
15 V to VBH
VBH
42.5 to 99 V
BGND with respect to GND
100 to +100 mV
Load resistance on VTX to Vref
20 k
minimum
Load resistance on VSAB to Vref
20 k
minimum
Description
Test Conditions
Min
Typ
Max
Unit
Power Dissipation Normal
Polarity
On-Hook Disconnect
55
70
mW
On-Hook Standby
80
100
On-Hook TransmissionLe79R241 ISLIC device
Fixed Longitudinal Voltage
175
215
On-Hook Active High Battery Le79R241 ISLIC
device
340
400
Off-Hook Active Low Battery
Le79R241 ISLIC device
RL = 294
TMG
700
200
800
Power Supply Currents
On-Hook Disconnect
VBH
VBL
VCC
0.4
0.1
3.0
0.7
3.5
mA
On-Hook Standby
VBH
VBL
VCC
0.75
0
3.1
1.1
3.5
On-Hook Transmission
VBH
Fixed Longitudinal Voltage
VBL
VCC
1.85
0
5
2.5
6
On-Hook Active High Battery
VBH
VBL
VCC
3.6
0
7.3
4.5
8.0
Off-Hook Active Low Battery
VBH
RL = 294
VBL
VCC
0.9
26.9
7.5
2.0
10
12
Le79R241 VE790 Series Data Sheet
DC Specifications
Unless otherwise specified, test conditions are: VCC = 5 V, RMGPi = RMGLi = 1 k
, BATH = 90 V,
BATL = 36 V, RRX = 150 k
, RL = 600 , RSA = RSB = 200 k, RFA = RFB = 50 , CHP = 22 nF,
CAD = CBD = 22 nF, IRSN = 50 A, Active low battery. DC-feed conditions are normally set by the 790
series codec. When the Le79R241 ISLIC device is tested by itself, its operating conditions must be
simulated as if it were connected to an ideal 790 series codec.
No.
Item
Condition
Min
Typ
Max
Unit
Note
1
Two-wire loop voltage
(including offset)
Standby mode, open circuit,
|VBH| < 55 V
|VBH| > 55 V
GND
- VB
Any Active mode (does not
include OHT),
RL = 600
, I
RSN
= 50 A
OHT mode, RL = 2200
I
RSN
= 20 A
VBH 8
48
13.88
19.8
VBH7
51
15
22
VBH6
55.5
55.5
16.13
V
2.
2
Feed resistance per leg
at pins AD & BD
Standby mode
130
250
375
ohms
2.
3
Feed current limit
Feed current
Standby mode, RL = 600
18
34
45
mA
IMT current
Standby mode, RL = 2200
44.6
56
A
ILG current
Standby mode
A to VBH
B to Ground
28
28
4
Ternary input voltage
boundaries for LD pin.
Mid-level input source
must be Vref.
Low boundary
Mid boundary
High boundary
Input high current
Input low current
Mid-level current
VREF0.3
CREF 1
V
REF
108
47
51
0.6
VREF+0.3
V
V
V
A
A
A
2.
2.
2.
5
Logic Inputs P1, P2, P3
Input high voltage
Input low voltage
Input high current
Input low current
2.0
-20
-20
0
0
0.8
20
20
V
V
A
A
6
VTX output offset
50
0
+50
mV
7
VREF input current
VREF = 1.4 V
50
A
2.
8
CREF input current
CREF = 3.3 V
-3
0
3
A
2.
9
, DC Ratio of VSAB to
loop voltage:
Tj < 145C, VSA VSB = 22 V
0.0088
0.0097
0.0106
V/V
10
Fault Indicator Threshold
Voltage Output on IMT
2.8
CREF 0.3 V
CREF
V
2.
11
Gain from VLB pin to A
or B pin, KLG
30
V/V
12
VLB pin input current
VLB = VREF 1 V
0
100
A
2.
13
ILOOP/IMT
ILOOP = 10 mA
283
308
333
A/A
14
ILONG/ILG
ILONG = 10 mA
575
615
655
A/A
15
Input current, SA and SB
pins
Active modes
1.0
3.0
A
2.
16
K1
Incremental DC current gain
462.5
500
537.5
A/A
2.
17
ISA/IMT
Disconnect ISA = 2 mA
4
6
8.75
18
ISB/ILG
Disconnect ISB = 2 mA
10
12
16
19
VSAB output offset
40C
+25C
+85C
7.0
3.6
1.4
mV
20
IMT output offset
3
0
3
A
21
ILG output offset
1
0
1
A
390 pf
RT Network
30 k
30 k
VREF
V
SAB
V
SA
V
SB
---------------------------
=
Le79R241 VE790 Series Data Sheet
13
Relay Driver Specifications
Figure 4. Relay Drivers
A. Relay Driver Configuration
B. Ring Relay
Item
Condition
Min
Typ
Max
Unit
Note
On Voltage
25 mA/relay sink
40 mA/relay sink
0.4
0.8
0.5
1.0
V
2
R2,R3 Off Leakage
R2,R3 = BGND
RYE = VBH
0
100
A
Zener Break Over
Iz = 100 A
6.6
7.9
10
V
Zener On Voltage
Iz = 30 mA
6
11
17
R2
RYE
R3
BGND
R1
14
Le79R241 VE790 Series Data Sheet
Transmission Specifications
No.
Item
Condition
Min
Typ
Max
Unit
Note
1
RSN input impedance
f = 300 to 3400 Hz
1
2.
2
VTX output impedance
3
3
Max, AC + DC loop current
Active High Battery or Active Low
Battery
70
mA
2.
4
Longitudinal impedance,
A or B to GND
Active mode
70
135
5
2-4 wire gain
10 dBm, 1 kHz, 0 to 70C
T
A
= 40C to 85C
14.13
14.18
13.98
13.98
13.83
13.78
dB
2.
6
2-4 wire gain variation with
frequency
300 to 3400 Hz, relative to 1 kHz
T
A
= 40C to 85C
0.1
0.15
+0.1
+0.15
2.
7
2-4 wire gain tracking
+3 dBm to 55 dBm
Reference: 10 dBm
T
A
= 40 to 85C
0.1
0.15
+0.1
+0.15
2.
,
5.
8
4-2 wire gain
10 dBm, 1 kHz
T
A
= 40C to 85C
0.15
0.2
+0.15
+0.2
2.
9
4-2 wire gain variation with
frequency
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
40C to 85C
0.1
0.15
+0.1
+0.15
2.
,
5.
11
Total harmonic distortion
level
2-wire
4-wire
4-wire overload level at VTX
OHT
300 Hz to 3400 Hz
0 dBm
11.2 dBm
12 dBm
0.8 dBm
RLOAD = 600
VAB - 50 V 0 dBm
1
50
50
40
48
38
dB
dB
dB
dB
Vp
dB
2.
2.
12
Idle channel noise
C-message
Weighted
Psophometric
Weighted
Active modes, R
L
= 600
2-wire
4-wire
2-wire
4-wire
+9
5
81
95
+11
79
dBrnC
dBmp
--
13
Longitudinal balance
(IEEE method)
Normal Polarity
L - T 200 to 1000 Hz
T
A
= 40C to 85C
1000 to 3400 Hz
T
A
= 40C to 85C
58
53
53
48
dB
2.
2.
T - L 200 to 3400 Hz
40
L - T, IL = 0 50 to 3400 Hz
63
3.
Reverse Polarity
L - T 200 to 1000 Hz
T
A
= 40C to 85C
50
48
2.
14
PSRR (VBH, VBL)
50 to 3400 Hz
3.4 to 50 kHz
25
45
40
3.
,
4.
1.
,
2.
,
4.
15
PSRR (VCC)
50 to 3400 Hz
3.4 to 50 kHz
25
45
35
3.
,
4.
1.
,
2.
,
4.
16
Longitudinal AC current per
wire
F = 15 to 60 Hz Active mode
20
30
mArms
2.
17
Metering distortion
Freq = 12 kHz 2.8 Vrms
Freq = 16 kHz
metering load = 200
40
dB
2.
Le79R241 VE790 Series Data Sheet
15
Ringing Specifications
Current-Limit Behavior
Thermal Shutdown Fault Indications
Note:
1.
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
2.
Not tested or partially tested in production. This parameter is guaranteed by characterization or correlation to other tests.
3.
This parameter is tested at 1 kHz in production. Performance at other frequencies is guaranteed by characterization.
4.
When the Le79R241 ISLIC device and 790 series codec is in the anti-sat operating region, this parameter is degraded. The exact
degradation depends on system design.
5.
55 dBm gain tracking level not tested in production. This parameter is guaranteed by characterization and correlation to other tests.
6.
This spec is valid from 0 V to VBL or 50 V, whichever is lower in magnitude.
7.
Other ringing-voltage characteristics are set by the 790 series codec.
OPERATING MODES
The Le79R241 ISLIC device 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 Le79R241 ISLIC device control register. When the LD pin is less than 0.3 V
below VREF (< (VREF 0.3 V)), P1P3 must contain data for relay control bits RD1, RD2 and RD3. These are latched into the
first three bits in the Le79R241 ISLIC device control register. When the LD pin is more than 0.3 V above VREF, P1P3 must
contain Le79R241 ISLIC device control data C1, C2, and C3, which are latched into the last three bits of the Le79R241 ISLIC
device control register. Connecting the LD pin to VREF locks the contents of the Le79R241 ISLIC device control register.
The operating mode of the Le79R241 ISLIC device is determined by the C1, C2, and C3 bits in the control register of the
Le79R241 ISLIC device. Table 1 defines the Le79R241 ISLIC device operating modes set by these signals.
Under normal operating conditions, the Le79R241 ISLIC device does not have active relays. The Le79R241 ISLIC device to
VE790 series 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 Le79R241 devices.
To perform external ringing, the VE790 series ISLAC device is set to external ringing mode (RMODE = 1), enables the ring relay,
and puts the Le79R241 ISLIC device in the Standby mode.
Item
Condition
Min
Typ
Max
Unit
Note
Peak Ringing Voltage
Active Internal Ringing
VBH+6
V
7.
SLIC Mode
Condition
Min
Typ
Max
Unit
Note
Disconnect
Applied fault between ground and T/R
VBH applied to Tip or Ring
1
VBH/200K
100
A
A
6.
Tip Open
Ring Short to GND
20
35
46
mA
Standby
Short Tip-to-VBH
Short Ring-to-GND
24
26
38
35
47
44
Active Ringing
790 series codec generating internal ringing
100
2.
Fault
Indication
No Fault
IMT operates normally (V
REF
1 V)
Thermal Shutdown
KG, IMT above 2.8 V; ILG operates normally
16
Le79R241 VE790 Series Data Sheet
Note:
1.
In these modes, the ring lead (B-lead) output has a 50 V internal clamp to battery ground (BGND).
Operating Mode Descriptions
Table 1. Operating Modes
C3
C2
C1
Operating Mode
Battery Voltage
Selection
Operating Mode
Connection to
RMGPi & RMGLi
Resistors
0
0
0
Standby (See note 1)
High Battery (BATH)
and BGND
(High ohmic feed): Loop supervision
active, A and B amplifiers shut down
Open
0
0
1
Tip Open (See note 1)
High Battery (BATH)
and BGND
Tip Open: AD at High-Impedance,
Channel A power amplifier shut down
Open
0
1
0
On-Hook
Transmission, Fixed
Longitudinal Voltage
High Battery (BATH)
and BGND
Fixed longitudinal voltage of 28 V
A and B Amplifier
Output
0
1
1
Disconnect
Low Battery
selection at VBL
AD and BD at High-Impedance,
Channel A and B power amplifiers
shut down
1
0
0
RSVD
Active feed, normal or reverse polarity
1
0
1
Active High Battery
High Battery (BATH)
and BGND
1
1
0
Active Low Battery
Low Battery (BATL)
and BGND
1
1
1
Active Internal Ringing
High Battery (BATH)
and BGND
Active internal ringing
Operating Mode
Description
Disconnect
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 Le79R241 ISLIC device 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 RMTi and RLGi of
and
, respectively.
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 to approximately 50 V with respect to
BGND. For VBH values above 55 V, the open-circuit voltage, which appears at this output is ~VBH + 7 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
Current-Limit Behavior, on page 15
. In external ringing,
the Standby Le79R241 ISLIC device state is selected.
Tip Open
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.
Active High
Battery
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.
Active Low
Battery
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.
Active Internal
Ringing
In the Internal Ringing mode, the Le79R241 ISLIC device 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.
On-Hook
Transmission
(OHT), Fixed
Longitudinal
Voltage
In the On-Hook Transmission, Fixed Longitudinal Voltage mode, battery connections are as shown in
Table 1
.
The longitudinal voltage is fixed at the voltage shown in
Table 1
to allow compliance with safety specifications
for some classes of products.
V
SA
400
----------
V
SB
400
----------
Le79R241 VE790 Series Data Sheet
17
Driver Descriptions
Control bits RD1, RD2, and RD3 do not affect the operating mode of the Le79R241 ISLIC device. These signals usually perform
the following functions.
Thermal-Management Equations
Applies to all modes except Standby and Ringing, which have no thermal management.
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 Le79R241 ISLIC device 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 Le79R241 ISLIC device 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.
Le79R241 ISLIC device registers are refreshed at 5.33 kHz when used with an 790 series codec.
5.
If the clock or MPI becomes disabled, the LD pins and P1
3 returns to 0 V state, protecting the Le79R241 ISLIC device and the line
connection.
Driver
Description
R1
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.
R2
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 line card. The test load must be connected to the Le79R241 ISLIC device side of the
protection resistor to avoid damage to the R2 driver.
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 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 line card. The test load must be connected to the Le79R241 ISLIC device side of the
protection resistor to avoid damage to the R3 driver.
Equation
Description
I
L
< 5 mA
P
SLIC
= (S
BAT
I
L
(R
L
+ 2R
FUSE
)) I
L
+ 0.3 W
PT
RTMG
= 0
TMG resistor-current is limited to be 5 mA < I
L
. If I
L
< 5 mA,
no current flows in the TMG resistor and it all flows in the
Am79241.
I
L
> 5 mA
RMGPi = RMGLi = R
TMG
PT
RTMG
: total power dissipation of RMGPi and RMGLi
R
TMG
= (S
BAT
I
L
(R
L
+ 2R
FUSE
)) / (2(I
L
5 mA))
P
SLIC
= I
L
(S
BAT
I
L
(R
L
+ 2R
FUSE
)) + 0.3 W PT
RTMG
PT
RTMG
= (I
L
5 mA)
2
(2R
TMG
)
These equations are valid when
R
TMG
(I
L
5 mA) < (S
BAT
(R
F
+ R
L
)I
L
) / 2 2
because the longitudinal voltage is one-half the battery
voltage and the TMG switches require approximately 2 V.
To choose a power rating for RTMG:
P
RATING
> PT
RTMG
/ 2
Symbol
Signal
Parameter
Min
Typ
Max
Unit
trSLD
LD
Rise time Le79R241 ISLIC device LD pin
2
us
tfSLD
LD
Fall time Le79R241 ISLIC device LD pin
2
tSLDPW
LD
LD minimum pulse width
3
tSDXSU
P1,P2,P3
P13 data Setup time
4.5
tSDXHD
P1,P2,P3
P13 data hold time
4.5
tSDXD
P1,P2,P3
Max P13 data delay
5
18
Le79R241 VE790 Series Data Sheet
6.
Not tested in production. Guaranteed by characterization.
WAVEFORMS
DETAIL A
t
SDXSU
t
SDXHD
t
SLDPW
tr
SLD
tf
SLD
LD
P1,P2,P3
0V
VREF
VCC
Write Relay Register
Write State Register
Lock Registers
LD
P1,P2,P3
Relay Data
State Data
Write State Register
Write Relay Register
New State
Data
Previous
Relay Data
VREF
VREF
t
SDXD
Relay driver
response
S R
S R
S R
P1,P2,P3
LD
187.5 s
Le79R241 VE790 Series Data Sheet
19
APPLICATION CIRCUITS
Figure 5. Internal Ringing Line Schematic
RFAi
RFBi
RSAi
RSBi
A
B
P1
P2
P3
LD
SA
SB
AD
BD
VBH
VBL
TMP
TMN
RSN
VLB
IMT
ILG
VTX
VREF
VSAB
GND
+5V
VCC
* Connections shown for one channel
RMGPi
TMS
BGND
R2
RYE
R3
R1
HPA
HPB
CHPi
RRXi
RMTi
VREF
RLGi
VREF
VREF
VILGi
VIMTi
VLBi
VSABi
VINi
VOUTi
BACK
PLANE
LDi
P1
P2
P3
DGND
VCCA
VCCD
SHB
SLB
BATH
BATL
IREF
AGND
VCC
+3.3VDC
RSHB
RSLB
RREF
CREF
3.3V
CADi
CBDi
RSVD
RTi
CS1
U3
BATH
U4
U5
BATP
U6
SPB
BATP
RSPB
VBP
BATP
CS2
DT2i
RHLai
VHLi
RHLbi
RHLci
RHLdi
VREF
CHLdi
CHLbi
XSBi
XSC
RTEST
DT1i
BATH
BATL
DLHi
CBATHi
RMGLi
DHi
DLi
CBATPi
CBATLi
U1
Le79R241
or
Le79R251
U2
Le79228x
codec
20
Le79R241 VE790 Series Data Sheet
LINE CARD PARTS LIST- INTERNAL RINGING
The following list defines the parts and part values required to meet target specification limits for channel i of the line card (i =
1,2,3,4).
Notes:
1.
Required to insure VBH < VBL during startup. May not be needed for some supplies.
2.
DT2i is optional - Should be put if Le79R251 is used.
3.
Value can be adjusted to suit application.
Item
Type
Value
Tol.
Rating
Comments
U1
Le79R241 ISLIC
device
-
U2
VE790 series ISLAC
device
-
codec
U3, U4, U5, U6
B1100CC
-
100 V
TECCOR Battrax protector
DT1
i
, DT2
i
Diode
1 A
-
100 V
DH
i
1
, DL
i
, DT1
i
, DT2
i
, DLH
i
Diode
100 mA
-
100 V
50 ns response time
RFA
i
, RFB
i
Resistor
50
2%
2 W
Fusible or PTC protection resistors
RSA
i
, RSB
i
Resistor
200 k
2%
1/4 W
Sense resistors
RT
i
Resistor
80.6 k
1%
1/8 W
Impedance control resistor
RRX
i
Resistor
90.9 k
1%
1/8 W
Receive path gain resistor
RREF
Resistor
69.8 k
1%
1/8 W
Current reference setting resistor
RSHB, RSLB, RSPB
Resistor
750 k
1%
1/8 W
Battery sense resistors
RHLa
i
Resistor
40.2 k
1%
1/10 W
Feed/metering resistor
RHLb
i
Resistor
4.32 k
1%
1/10 W
Feed/metering resistor
RHLc
i
Resistor
2.87 k
1%
1/10 W
Feed/metering resistor
RHLd
i
Resistor
2.87 k
1%
1/10 W
Feed/metering resistor
CHLb
i
Capacitor
3.3 nF
10%
10 V
Feed/metering capacitor - Not Polarized
CHLd
i
Capacitor
0.82
F
10%
10 V
Feed/metering capacitor -Ceramic
RMT
i
Resistor
3.01 k
1%
1/8 W
Metallic loop current gain resistor
RLG
i
Resistor
6.04 k
1%
1/8 W
Longitudinal loop current gain resistor
RTEST
Resistor
2 k
1%
1 W
Test board
CAD
i
, CBD
i
2
Capacitor
22 nF
10%
100 V
Ceramic
CBATH
i
, CBATL
i
, CBATP
i
Capacitor
100 nF
20%
100 V
Ceramic
CHP
i
Capacitor
22 nF
20%
100 V
High pass filter capacitor - Ceramic
CS1
i
, CS2
i
2
Capacitor
100 nF
20%
100 V
Protector speed up capacitor
RMGL
i
Resistor
1 k
5%
2 W
Thermal management resistor
RMGP
i
Resistor
1 k
5%
2 W
Thermal management resistor
Le79R241 VE790 Series Data Sheet
21
Figure 6. External Ringing Line Schematic
RFAi
RFBi
RSAi
RSBi
RRXi
A
B
P1
P2
P3
LD
RSN
VLB
IMT
ILG
VTX
VREF
VSAB
GND
+5 V
VCC
CBATLi
*Connections shown for one channel
**DT2i is optional - Should be put if Le79R251 is used.
RMGLi
RMGPi
RMTi
VREF
RLGi
VREF
RHLai
BATH
CS
4
5
8
1
2
U5
6
7
DT1i
RSRBi
RSRC
RGFDi
Ring Bus
KRi
KRi(A)
CADi
CBDi
CHPi
U2
ISLAC
VREF
VILGi
VIMTi
VLBi
VSABi
VINi
VHLi
VOUTi
BACK
PLANE
LDi
P1
P2
P3
DGND
AGND
VCCA
VCCD
RSHB
RSLB
SHB
SLB
BATH
BATL
RREF
IREF
XSBi
XSC
VCC
+3.3 VDC
+5 V
KRi
SPB
RSVD
CREF
3.3 V
RTi
(B)
DT2i
***
RHLbi
RHLci
RHLdi
VREF
CHLdi
CHLbi
SA
SB
AD
BD
VBH
VBL
TMP
TMN
TMS
BGND
R2H
RYE
R3H
R1
HPA
HPB
RSVD2
VBP
DHi
BATH
BATL
DLHi
DLi
CBATHi
U1
Le79231,
Le79R241
or
Le79R251
U2
Le79Q224x
or Le79228x
codec
RTEST
22
Le79R241 VE790 Series Data Sheet
LINE CARD PARTS LIST - EXTERNAL RINGING
The following list defines the parts and part values required to meet target specification limits for channel i of the line card (i = 1,
2, 3, 4).
Notes:
1.
Required to insure VBH < VBL during startup. May not be needed for some supplies.
2.
DT2i is optional - Should be put if Le79R251 is used.
3.
Value can be adjusted to suit application.
Item
Type
Value
Tol.
Rating
Comments
U1
Le79R241 ISLIC device
U2
VE790 series ISLAC
device
codec
U5
TISP61089
80 V
Transient Voltage Suppressor, Power
Innovations
DLH
i
1
, DH
i
, DL
i
, DT1
i
DT2i
2
Diode
100 mA
100 V
50 ns response time
RFA
i
, RFB
i
Resistor
50
2%
2 W
Fusible or PTC protection resistors
RSA
i
, RSB
i
Resistor
200 k
2%
1/4 W
Sense resistors
RT
i
Resistor
80.6 k
1%
1/8 W
Impedance control resistor
RRX
i
Resistor
90.9 k
1%
1/8 W
Receive path gain resistor
RREF
Resistor
69.8 k
1%
1/8 W
Current reference setting resistor
RMGL
i
, RMGP
i
Resistor
1 k
5%
1 W
Thermal management resistors
RSHB, RSLB
Resistor
750 k
1%
1/8 W
Battery Sense Resistors
RHLa
i
Resistor
40.2 k
1%
1/10 W
Feed/Metering resistor
RHLb
i
Resistor
4.32 k
1%
1/10 W
Feed/Metering resistor
RHLc
i
Resistor
2.49 k
1%
1/10 W
Use 2.87k
in metering
Feed/Metering resistor
RHLd
i
Resistor
2.49 k
1%
1/10 W
Use 2.87k
in metering
Feed/Metering resistor
CHLb
i
Capacitor
3.3 nF
10%
10 V
Feed/Metering capacitor - Not Polarized
CHLd
i
Capacitor
0.82 F
10%
10 V
Feed/Metering capacitor - Ceramic
RMT
i
Resistor
3.01 k
1%
1/8 W
Metallic Current Sense Resistors
RLG
i
Resistor
6.04 k
1%
1/8 W
Longitudinal Current Sense Resistors
RTEST
Resistor
2 k
1%
1 W
Test board
CAD
i
, CBD
i
3
Capacitor
22 nF
10%
100 V
Ceramic
CBATH
i
, CBATL
i
Capacitor
100 nF
20%
100 V
Ceramic
CHP
i
Capacitor
22 nF
20%
100 V
Ceramic
CS
i
3
Capacitor
100 nF
20%
100 V
Protector speed up capacitor
RGFD
i
Resistor
510
2%
2 W
1.2 W typ
RSRB
i
, RSRC
Resistor
750 k
1%
1/4 W
External Ringing sense resistors
KR
i
Relay
5 V Coil
DPDT
Le79R241 VE790 Series Data Sheet
23
PHYSICAL DIMENSIONS
32-Pin PLCC
Note:
Packages may have mold tooling markings on the surface. These markings have no impact on the form, fit or function of the
device. Markings will vary with the mold tool used in manufacturing.
24
Le79R241 VE790 Series Data Sheet
32-Pin QFN
Note:
Packages may have mold tooling markings on the surface. These markings have no impact on the form, fit or function of the
device. Markings will vary with the mold tool used in manufacturing.
NOTES:
1. Dimensioning and tolerancing conform to ASME Y14.5M-1994.
2. All dimensions are in millimeters. is in degrees.
3. N is the total number of terminals.
4. The Terminal #1 identifier and terminal numbering convention
shall conform to JEP 95-1 and SSP-012. Details of the Terminal #1
identifier are optional, but must be located within the zone
indicated. The Terminal #1 identifier may be either a mold or
marked feature.
5. Coplanarity applies to the exposed pad as well as the terminals.
6. Reference Document: JEDEC MO-220.
7. Lead width deviates from the JEDEC MO-220 standard.
0.57
0.80
0.90
1.00
REF
0.18
0.23
0.28
8.00 BSC
5.70
5.80
5.90
8.00 BSC
5.70
5.80
5.90
0.80 BSC
0.43
0.53
0.63
32
0.00
0.02
0.05
0.20 REF
0.20
0.10
0.10
32 LEAD QFN
Symbol
Min
Nom
Max
32 Lead QFN with Chamfer
Le79R241 VE790 Series Data Sheet
25
REVISION HISTORY
Revision H to Revision I
Page 11, Figure 3, DT1i was added and the last note was modified.
Page 12, Figure 4, DT1i was added and the last note was modified.
Page 15, Electrical Characteristics, Numbers changed in the Max column.
Page 16, Absolute Maximum Ratings, The "Humidity" row was deleted.
Page 17, Specifications, There were changes to rows one, four, six, 12, and 1721, and to the Note column.
Page 18, Relay Driver Specifications, There were changes in the last two rows.
Page 19, Transmission Specifications, There were changes to rows, six, eight, 10, and 13, and to the Note column.
Page 20, Fault Indications, "ILG operates normally" was deleted from the Indication column on the second row.
Revision I to Revision J
Applied new format.
Global change: RTMG1 to RMGLi, and RTMG2 to RMGPi.
Updated "Target Specifications" for rows 10, and 19.
Updated "Transmission Specifications" for row 12.
"Thermal Management Equations" modified.
Added "Applications" section.
Revision J to K
Added 5 REN bullet to Features.
Updated Device Internal Block Diagram.
Modified description of LD pin.
In "Thermal Resistance" section, updated temperature to 43
C.
New Temperature statement added to "Chipset Features".
New Temperature statement added to "Environmental Ranges".
Removed reference to V
LOOPMAX
in the "Electrical Ranges" section.
"Waveforms," new image.
In "DC Specificaitons" section, the following changes were made:
Added test conditions for two-wire loop voltage.
Added a typical value for Ternary input voltage, Mid boundary.
Removed references to T
A
under test conditions for idle channel noise.
"DC Specifications," "Transmission Specifications," and "Line Card Parts List," corrected W's to omega's.
Added typical value for Ringing Specifications.
Renamed "Fault Indications" table to "Thermal Shutdown Fault Indications"; modified text.
Modified text in "Operating Modes" section.
"Thermal-Management Equations," corrected "P
TMG
" to "PT
RTMG
" and corrected "(R
L
I
L
)" to "(R
F
+ R
L
)I
L
."
"Application Circuits," added line to arrow head at DT1i, and deleted "H" from R2 and R3.
Modified note for External Ringing Line card schematic.
Revision K to L
Added QFN package data to "Connection Diagram," "Absolute Maximum Ratings," and "Physical Dimensions."
Updated "Am" OPNs (Ordering Part Numbers) to "Le" throughout document
In "Ordering Information" the following changes were made:
Added entries for Le79R241JC and Le79R241QC
Removed the chip graphic
Added notes
In "Features," added bullet for space savings feature
Removed references to DISLAC documents in "Related Literature"
In "Pin Descriptions," added row describing exposed pad
Standardized notes in "Absolute Maximum Ratings" section
26
Le79R241 VE790 Series Data Sheet
In "Thermal Management Equations", I
L
> 5 mA, deleted the last sentence in the Description section
Updated 32-Pin PLCC physical dimensions graphic
Revision L to M1
Modified internal and external ringing schematics and BOMs (removed CSS capacitor)
Updated QFN Physical Dimensions drawing
Revision M1 to N1
Added 5.1-k VHL network in to both application circuits in
Application Circuits, on page 19
Revision N1 to O1
Added Packing column and related note to
Ordering Information, on page 1
.
Added green package OPNs to
Ordering Information, on page 1
.
Added
Package Assembly, on page 10
Revised DC Specifications, page 12, No. 12, 13 for I
LOOP
/I
MT
and I
LONG
/I
LG
for min. typ and max.
Added note to
Physical Dimensions, on page 23
The contents of this document are provided in connection with Legerity, Inc. products. Legerity 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
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2005 Legerity, Inc.
All rights reserved.
Trademarks
Legerity, the Legerity logo and combinations thereof, and VoiceEdge, SLAC, ISLAC, ISLIC, WinSLAC are trademarks of Legerity, Inc.
Other product names used in this publication are for identification purposes only and may be trademarks of their respective companies.
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