Electronic Components Datasheet Search
  English  ▼
ALLDATASHEET.COM

X  

L7581 Datasheet(PDF) 8 Page - Agere Systems

Part # L7581
Description  Ringing Access Switch
Download  16 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  AGERE [Agere Systems]
Direct Link  
Logo AGERE - Agere Systems

L7581 Datasheet(HTML) 8 Page - Agere Systems

Back Button L7581 Datasheet HTML 4Page - Agere Systems L7581 Datasheet HTML 5Page - Agere Systems L7581 Datasheet HTML 6Page - Agere Systems L7581 Datasheet HTML 7Page - Agere Systems L7581 Datasheet HTML 8Page - Agere Systems L7581 Datasheet HTML 9Page - Agere Systems L7581 Datasheet HTML 10Page - Agere Systems L7581 Datasheet HTML 11Page - Agere Systems L7581 Datasheet HTML 12Page - Agere Systems Next Button
Zoom Inzoom in Zoom Outzoom out
 8 / 16 page
background image
8
8
Lucent Technologies Inc.
Data Sheet
November 1999
L7581 Ringing Access Switch
Power Supplies
Both the 5 V and battery supply are brought onto the
L7581. The L7581 requires only the 5 V supply for
switch operation; that is, state control is powered exclu-
sively off of the 5 V supply. Because of this, the L7581
offers extremely low power dissipation, both in the idle
and active states.
The battery voltage is not used for switch state control.
The battery is used as a reference voltage by the inte-
grated secondary protection circuit. When the voltage
at TBAT or RBAT drops 2 V to 4 V below the battery, the
integrated SCR will trigger, thus preventing fault-
induced overvoltage situations at the TBAT/RBAT nodes.
Loss of Battery Voltage
As an additional protection feature, the L7581 monitors
the battery voltage. Upon loss of battery voltage, the
L7581 will automatically enter an all OFF state and
remain in that state until the battery voltage is restored.
The L7581 is designed so that the device will enter the
all OFF state if the battery rises above –10 V and will
remain off until the battery drops below –15 V.
Monitoring the battery for the automatic shutdown fea-
ture will draw a small current from the battery, typically
4 µA. This will add slightly to the overall power dissipa-
tion of the device.
Impulse Noise
Using the L7581 will minimize and possibly eliminate
the contribution to the overall system impulse noise
that is associated with ringing access switches.
Because of this characteristic of the L7581, it may not
be necessary to incorporate a zero cross switching
scheme. This ultimately depends upon the characteris-
tics of the individual system and is best evaluated at
the board level.
Protection
Integrated SLIC Protection
Diode Bridge/SCR
In the L7581Axx version, protection to the SLIC device
or other subsequent circuitry is provided by a combina-
tion of current-limited break switches, a diode bridge/
SCR clamping circuit, and a thermal shutdown mecha-
nism. In the L7581Bxx version, protection to the SLIC
device or other subsequent circuitry is provided by a
combination of current-limited break switches, a diode
bridge, and a thermal shutdown mechanism.
In both versions, during a positive lightning event, fault
current is directed to ground via steering diodes in the
diode bridge. Voltage is clamped to a diode drop above
ground. In the A version, negative lightning causes the
SCR to conduct when the voltage goes 2 V to 4 V more
negative than the battery, and fault currents are
directed to ground via the SCR and steering diodes in
the diode bridge.
Note that for the SCR to foldback or crowbar, the ON
voltage (see Table 10) of the SCR must be less nega-
tive than the battery reference voltage. If the battery
voltage is less negative than the SCR ON voltage, the
SCR will conduct fault currents to ground; however, it
will not crowbar.
In the B version, negative lightning is directed to battery
via steering diodes in the diode bridge.
For power cross and power induction faults, in both ver-
sions, the positive cycle of the fault is clamped a diode
drop above ground and fault currents steered to
ground. In the A version, the negative cycle will cause
the SCR to trigger when the voltage exceeds the bat-
tery reference voltage by 2 V to 4 V. When the SCR
triggers, fault current is steered to ground. In the B ver-
sion, the negative cycle of the power cross is steered to
battery.
Current Limiting
During a lightning event, the current that is passed
through the break switches and presented to the inte-
grated protection circuit and subsequent circuitry is lim-
ited by the dynamic current-limit response of the break
switches (assuming idle/talk state). When the voltage
seen at the TLINE/RLINE nodes is properly clamped by
an external secondary protector, upon application of a
1000 V 10 x 1000 pulse (LSSGR lightning), the current
seen at the TBAT/RBAT nodes will typically be a pulse of
magnitude 2.5 A and duration less than 0.5 µs.


Similar Part No. - L7581

ManufacturerPart #DatasheetDescription
logo
Agere Systems
L7582 AGERE-L7582 Datasheet
331Kb / 16P
   Tip Ring Access Switch
L7583A AGERE-L7583A Datasheet
486Kb / 20P
   Line Card Access Switch
L7585F AGERE-L7585F Datasheet
441Kb / 22P
   Full-Feature,Low-Power SLIC and Switch
L7585G AGERE-L7585G Datasheet
446Kb / 22P
   Full-Feature,Low-Power SLIC and Switch
More results

Similar Description - L7581

ManufacturerPart #DatasheetDescription
logo
Mitel Networks Corporat...
MT90866 MITEL-MT90866 Datasheet
34Kb / 6P
   WAN Access Switch
logo
Agere Systems
L9310 AGERE-L9310 Datasheet
1Mb / 60P
   Line Interface and Line Access Circuit Full-Feature SLIC,Ringing Relay,and Test Access Device
logo
Clare, Inc.
CPC7581 CLARE-CPC7581 Datasheet
122Kb / 12P
   Line Card Access Switch
CPC7582 CLARE-CPC7582_1 Datasheet
572Kb / 19P
   Line Card Access Switch
logo
IXYS Corporation
CPC7593 IXYS-CPC7593 Datasheet
321Kb / 24P
   Line Card Access Switch
logo
Clare, Inc.
CPC7691 CLARE-CPC7691 Datasheet
481Kb / 17P
   Line Card Access Switch
CPC75282 CLARE-CPC75282 Datasheet
672Kb / 19P
   Line Card Access Switch
CPC7591 CLARE-CPC7591 Datasheet
556Kb / 19P
   Line Card Access Switch
logo
IXYS Corporation
CPC7581 IXYS-CPC7581_12 Datasheet
1,017Kb / 15P
   Line Card Access Switch
logo
Agere Systems
L7582 AGERE-L7582 Datasheet
331Kb / 16P
   Tip Ring Access Switch
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16


Datasheet Download

Go To PDF Page


Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ] 

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   Link Exchange   |   Manufacturer List
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com