Electronic Components Datasheet Search
  English  ▼
ALLDATASHEET.NET

X  

CPC7581 Datasheet(PDF) 9 Page - Clare, Inc.

Part # CPC7581
Description  Line Card Access Switch
Download  12 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  CLARE [Clare, Inc.]
Direct Link  http://www.clare.com
Logo CLARE - Clare, Inc.

CPC7581 Datasheet(HTML) 9 Page - Clare, Inc.

Back Button CPC7581 Datasheet HTML 4Page - Clare, Inc. CPC7581 Datasheet HTML 5Page - Clare, Inc. CPC7581 Datasheet HTML 6Page - Clare, Inc. CPC7581 Datasheet HTML 7Page - Clare, Inc. CPC7581 Datasheet HTML 8Page - Clare, Inc. CPC7581 Datasheet HTML 9Page - Clare, Inc. CPC7581 Datasheet HTML 10Page - Clare, Inc. CPC7581 Datasheet HTML 11Page - Clare, Inc. CPC7581 Datasheet HTML 12Page - Clare, Inc.  
Zoom Inzoom in Zoom Outzoom out
 9 / 12 page
background image
CPC7581
www.clare.com
9
Rev. 2
Battery Voltage Monitor
The CPC7581 also uses the voltage reference to moni-
tor battery voltage. If battery voltage is lost, the CPC7581
will immediately enter the “all off” state and remain in this
state until the battery voltage is restored. The device will
also enter the “all off” state if the battery voltage rises
above –10V and will remain there until the battery volt-
age drops below –15V. This battery monitor feature
draws a small current from the battery (< 1
µA typ.) and
will add slightly to the device’s overall power dissipation.
Protection
Diode Bridge/SCR
The CPC7581 uses a combination of current limited
break switches, a diode bridge/SCR clamping circuit
and a thermal shutdown mechanism to protect the SLIC
device or other associated circuitry from damage during
line transient events such as lightning. During a positive
transient condition, the fault current is conducted
through the diode bridge and to ground. Voltage is
clamped to the diode drop above ground. During a neg-
ative transient of two to four volts more negative than
the battery, the SCR conducts and faults are shunted to
ground via the SCR and diode bridge.
Also, in order for the SCR to crowbar or foldback, the on
voltage (see Table 7) of the SCR must be less negative
than the battery reference voltage. If the battery voltage
is less negative the SCR on voltage, the SCR will not
crowbar, however it will conduct fault currents to ground.
For power induction or power cross fault conditions, the
positive cycle of the transient is clamped to the diode
drop above ground and the fault current directed to
ground. The negative cycle of the transient will cause
the SCR to conduct when the voltage exceeds the bat-
tery reference voltage by two to four volts, steering the
current to ground.
Current Limiting function
If a lightning strike transient occurs when the device in
the talk/idle state, the current is passed along the line to
the integrated protection circuitry and limited by the
dynamic current limit response of break switches SW1
and SW2. When a 1000V 10x1000 pulse (LSSGR light-
ning) is applied to the line though a properly clamped
external protector, the current seen at pins 2 (T
BAT) and
pin 15 (R
BAT) will be a pulse with a typical magnitude
and duration of 2.5A and < 0.5ms.
If a power cross fault occurs with device in the talk/idle
state, the current is passed though the break switches
SW1 and SW2 on to the integrated protection circuit
and is limited by the dynamic DC current limit response
of the two break switches. The DC current limit, specified
over temperature, is between 80mA and 425mA and the
circuitry has a negative temperature coefficient. As a
result, if the device is subjected to extended heating due
to power cross fault, the measured current at pin 2 (T
BAT)
and pin 15 (R
BAT) will decrease as the device tempera-
ture increases. If the device temperature rises sufficient-
ly, the temperature shutdown mechanism will activate
and the device will default to the “all off” state.
Temperature Shutdown
The thermal shutdown mechanism will activate when
the device temperature reaches a minimum of 110°C
placing the device in the “all off” state regardless of logic
input. During this thermal shutdown mode, pin 8 (TSD)
will read 0V. Normal output of TSD is +V
DD
If presented with a short duration transient such as a
lightning event, the thermal shutdown feature will not
typically activate. But in an extended power cross tran-
sient, the device temperature will rise and the thermal
shutdown will activate forcing the switches to an “all off”
state. At this point the current measured at pin 2 (T
BAT)
and pin 15 (R
BAT) will drop to zero. Once the device
enters thermal shutdown it will remain in the “all off”
state until the temperature of the device drops below
the activation level of the thermal shutdown circuit. This
will return the device to the state prior to thermal shut-
down. If the transient has not passed, current will flow
at the value allowed by the dynamic DC current limiting
of the switches and heating will begin again, reactivat-
ing the thermal shutdown mechanism. This cycle of
entering and exiting the thermal shutdown mode will
continue as long as the fault condition persists. If the
magnitude of the fault condition is great enough, the
external secondary protector could activate and shunt
all current to ground.
External Protection Elements
The CPC7581 requires only one overvoltage secondary
protector on the loop side of the device. The integrated
protection feature described above negates the need
for protection on the line side. The purpose of the sec-
ondary protector is to limit voltage transients to levels
that do not exceed the breakdown voltage or input-out-
put isolation barrier of the CPC7581. A foldback or
crowbar type protector is recommended to minimize
stresses on the device.
Consult Clare’s application note, AN-100, “Designing
Surge and Power Fault Protection Circuits for Solid
State Subscriber Line Interfaces” for equations related
to the specifications of external secondary protectors,
fused resistors and PTCs.


Similar Part No. - CPC7581

ManufacturerPart #DatasheetDescription
logo
Clare, Inc.
CPC7581 CLARE-CPC7581 Datasheet
532Kb / 17P
   Line Card Access Switch
logo
IXYS Corporation
CPC7581 IXYS-CPC7581 Datasheet
218Kb / 15P
   Clean, Bounce-Free Switching
CPC7581BA IXYS-CPC7581BA Datasheet
1,017Kb / 15P
   Line Card Access Switch
CPC7581BA IXYS-CPC7581BA Datasheet
218Kb / 15P
   Clean, Bounce-Free Switching
logo
Clare, Inc.
CPC7581BATR CLARE-CPC7581BATR Datasheet
532Kb / 17P
   Line Card Access Switch
More results

Similar Description - CPC7581

ManufacturerPart #DatasheetDescription
logo
Clare, Inc.
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
Clare, Inc.
CPC7582 CLARE-CPC7582 Datasheet
147Kb / 12P
   Line Card Access Switch
CPC7595 CLARE-CPC7595_1 Datasheet
664Kb / 24P
   Line Card Access Switch
CPC7595 CLARE-CPC7595 Datasheet
562Kb / 25P
   Line Card Access Switch
CPC7581 CLARE-CPC7581_1 Datasheet
532Kb / 17P
   Line Card Access Switch
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12


Datasheet Download

Go To PDF Page


Link URL




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

About Alldatasheet   |   Advertisement   |   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