L3121B Datasheet, PDF (1/7 Pages) STMicroelectronics – PROGRAMMABLE TRANSIENT VOLTAGE SUPPRESSOR FOR SLIC PROTECTION

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Application Specific Discretes
A.S.D.^TM
L3121B
PROGRAMMABLE TRANSIENT VOLTAGE
SUPPRESSOR FOR SLIC PROTECTION
FEATURES
BIDIRECTIONAL FUNCTION WITH VOLTAGE
PROGRAMMABILITY IN BOTH POSITIVE AND
NEGATIVE POLARITIES.
PROGRAMMABLE BREAKDOWN VOLTAGE
UP TO 100 V.
HOLDING CURRENT = 150 mA min.
HIGH SURGE CURRENT CAPABILITY.
IPP = 100A , 10/1000 µs
SIP4
DESCRIPTION
This device has been especially designed to pro-
tect a subscriber line interface circuit (SLIC) with
an integrated ring generator.
Used with the recommended application circuit,
each line (TIP and RING) is protected against posi-
tive and negative surges. In the positive polarity,
the breakdown voltage is referenced to the + VB ,
and in the negative polarity, the breakdown voltage
is referenced to the -Vbat .
Its high surge current capability makes the L3121B
a reliable protectiondevice for very exposed equip-
ment, or when series resistors are very low.
SCHEMATIC DIAGRAM
CONNECTION DIAGRAM
Line
Gate P
Gate N
GND
May 1999 - Ed:4A
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