900,000+ datasheet pdf search and download

Datasheet4U offers most rated semiconductors data sheet pdf






Agere Systems

L8574D Datasheet Preview

L8574D Datasheet

Resistive SLIC / Ring Relay and Protector

No Preview Available !

Data Sheet
October 1998
L8574D Resistive Subscriber Line Interface Circuit (SLIC), Ring
Relay, and Protector (SRP) for Long Loop and TR-57 Applications
Features
s Low-power scan mode for low on-hook power dis-
sipation (55 mW max)
s Low active power dissipation; talk or on-hook
transmission (240 mW max)
s Distortion-free on-hook transmission
s Eight operating states via latched paralleled data
inputs with channel select feature
s Precision fixed 28 mA current limiter
s Integrated protection
s No external protection device required
s Integrated ringing access relay
s Ring trip detector
s Loop closure detector with hysteresis
s Relay driver
s Battery noise cancellation
s Thermal protection
s 44-pin, surface-mount, plastic package (PLCC)
Description
The L8574 is a resistive subscriber line interface cir-
cuit (SLIC) that is optimized for long loop applica-
tions, such as Bellcore TR-NWT-000057
requirements for digital loop carrier (DLC) applica-
tions. It interfaces the low-voltage circuits on an ana-
log line card to the Tip/Ring subscriber loop. The
L8574 does not supply dc current to the subscriber
loop; external resistors are used for this purpose.
Included in the L8574 are a solid-state ringing
access switch and a line break switch. Also included
is a relay driver for an external (test) access mechan-
ical relay.
State control is via four latched parallel data inputs. A
chip select feature allows the user to enable, disable,
or reset the data latches to a known logic state.
The L8574 offers a low-power scan state to minimize
power to less than 55 mW in the on-hook state. The
L8574 also supports on-hook transmission. The
active power in both the talk or on-hook transmission
mode is also very low (<240 mW). Current is limited
to a fixed value of 25 mA by an internal precision
current-limit circuit.
Because of the internal architecture of the L8574
SLIC and because of the power rating of the associ-
ated external feed resistors, the L8574 will meet most
surge requirements without use of an external sec-
ondary protection device. Internal circuitry steers
both positive and negative faults to fault ground. Neg-
ative faults are not dumped into battery.
The L8574 is a two-chip line interface solution pack-
aged in a single, 44-pin PLCC package. The Tip and
Ring drive amplifiers, the XMT amplifier, the receive
interface, and battery noise cancellation circuits are
fabricated in a 90 V complementary bipolar (CBIC)
process. The ring access switch, line break switch,
battery switch, current-limit, protection functions,
supervision, and control functions are fabricated in a
320 V dielectrically isolated bipolar-CMOS-DMOS
(BCDMOS) process. The device is available in a
44-pin PLCC package.




Agere Systems

L8574D Datasheet Preview

L8574D Datasheet

Resistive SLIC / Ring Relay and Protector

No Preview Available !

L8574D Resistive Subscriber Line Interface Circuit (SLIC), Ring
Relay, and Protector (SRP) for Long Loop and TR-57 Applications
Data Sheet
October 1998
Table of Contents
Contents
Page
Features ....................................................................................................................................................................1
Description ................................................................................................................................................................1
Architectural Diagram ................................................................................................................................................4
Pin Information ..........................................................................................................................................................4
Absolute Maximum Ratings.......................................................................................................................................6
Electrical Characteristics ...........................................................................................................................................7
Ring Trip Detector ...................................................................................................................................................8
Battery Feed ...........................................................................................................................................................8
Fault Protection .......................................................................................................................................................9
Transmission Characteristics ................................................................................................................................13
Data Interface and Logic.......................................................................................................................................14
Switch Characteristics...........................................................................................................................................15
Operating States......................................................................................................................................................16
Scan State ............................................................................................................................................................16
Disconnect State...................................................................................................................................................17
Alternate Talk State ...............................................................................................................................................17
Talk State ..............................................................................................................................................................17
Scan Current-Limit State.......................................................................................................................................17
Ringing State ........................................................................................................................................................17
On-Hook Transmission State ................................................................................................................................17
Intermediate Talk State .........................................................................................................................................18
Applications .............................................................................................................................................................18
General .................................................................................................................................................................18
Resistor Module ....................................................................................................................................................22
Protection..............................................................................................................................................................24
Tip/Ring Drivers ....................................................................................................................................................25
Receive Interface ..................................................................................................................................................25
Transmit Interface..................................................................................................................................................25
Battery Noise Cancellation ...................................................................................................................................25
On-Hook Transmission..........................................................................................................................................26
Parallel Data Interface...........................................................................................................................................26
Supervision ...........................................................................................................................................................26
Off-Hook Detection ...............................................................................................................................................26
Ring Trip ................................................................................................................................................................26
Thermal Shutdown................................................................................................................................................27
Relay Driver ..........................................................................................................................................................27
Solid-State Ringing Access...................................................................................................................................27
Battery Supplies....................................................................................................................................................27
dc Characteristics ....................................................................................................................................................27
V-I Characteristics.................................................................................................................................................27
Loop Length ..........................................................................................................................................................28
ac Design.................................................................................................................................................................28
Codec Features and Selection Summary .............................................................................................................28
Design Equations..................................................................................................................................................29
Application Diagram ................................................................................................................................................33
Outline Diagram.......................................................................................................................................................34
44-Pin PLCC .........................................................................................................................................................34
Ordering Information................................................................................................................................................35
2 Lucent Technologies Inc.


Part Number L8574D
Description Resistive SLIC / Ring Relay and Protector
Maker Agere Systems
Total Page 30 Pages
PDF Download

L8574D Datasheet PDF

View PDF for Mobile








Similar Datasheet

1 L8574D Resistive SLIC / Ring Relay and Protector
Agere Systems





Part Number Start With

0    1    2    3    4    5    6    7    8    9    A    B    C    D    E    F    G    H    I    J    K    L    M    N    O    P    Q    R    S    T    U    V    W    X    Y    Z

Site map

Webmaste! click here

Contact us

Buy Components

Privacy Policy