Data Sheet
L8583D Line Card Access Switch
October 2002
I |Vringingpeakmax| + |VBATmax| < |Vbreakovermin|.
where:
Protection (continued)
Integrated SLIC Protection (continued)
External Secondary Protector
I VBATmax—Maximum magnitude of battery voltage.
I Vbreakovermax—Maximum magnitude breakover
voltage of external secondary protector.
With the above integrated protection features, only one
overvoltage secondary protection device on the loop
side of the L8583D is required. The purpose of this
device is to limit fault voltages seen by the L8583D so
as not to exceed the breakdown voltage or input-output
isolation rating of the device. To minimize stress on the
L8583D, use of a foldback-type or crowbar-type device
is recommended. A detailed explanation and design
equations on the choice of the external secondary pro-
tection device are given in the An Introduction to L758X
Series of Line Card Access Switches Application Note.
Basic design equations governing the choice of exter-
nal secondary protector are given below:
I Vbreakovermin—Minimum magnitude breakover
voltage of external secondary protector.
I Vbreakdownmin(break)—Minimum magnitude
breakdown voltage of L8583D break switch.
I Vbreakdownmin(ring)—Minimum magnitude break-
down voltage of L8583D ring access switch.
I Vringingpeakmax—Maximum magnitude peak volt-
age of ringing signal.
Series current-limiting fused resistors or PTCs should
be chosen so as not to exceed the current rating of the
external secondary protector. Refer to the manufac-
turer’s data sheet for requirements.
I |VBATmax| + |Vbreakovermax| <
|Vbreakdownmin(break)|.
I |Vringingpeakmax| + |VBATmax| +
|Vbreakovermax| < |Vbreakdownmin(ring)|.
Table 15. Electrical Specifications, Protection Circuitry
Parameters Related to Diodes (in Diode Bridge)
Parameter
Test Condition
Measure
Min
Typ
Max
Unit
Voltage Drop at Continuous Current (50
Hz/60 Hz)
Apply ±dc current limit of
Forward
Voltage
—
—
3.5
V
break switches
Voltage Drop at Surge Current
Apply ±dynamic current
limit of break switches
Forward
Voltage
—
5
—
V
14
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