description
The TISPPBL2S is a dual forward-conducting buffered p-gate overvoltage protector. It is designed to protect the Ericsson Components PBL 3xxx family of SLICs (Subscriber Line Interface Circuits) against overvoltages on the telephone line caused by lightning, a.c. power contact and induction. The TISPPBL2S limits voltages that exceed the SLIC supply rail levels.

The SLIC line driver section is typically powered from 0 V (ground) and a negative voltage in the region of -10 V to -85 V. The protector gate is connected to this negative supply. This references the protection (clipping) voltage to the negative supply voltage. As the protection voltage will track the negative supply voltage the overvoltage stress on the SLIC is minimised.