DESCRIPTION
This device has been especially designed to protect 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 positive 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 protection device for very exposed equipment, or when series resistors are very low.

FEATURES
■ BIDIRECTIONAL FUNCTION WITH VOLTAGE PROGRAMMABILITYIN BOTH POSITIVE AND NEGATIVE POLARITIES.
■ PROGRAMMABLE BREAKDOWN VOLTAGE UP TO 100 V.
■ HOLDING CURRENT = 150 mA min.
■ HIGH SURGE CURRENT CAPABILITY.
   IPP = 100A , 10/1000µs