BOURNS TISP61521DR-S

The TISP61521 is a dual forward-conducting buffered p gate overvoltage protector. It is designed to protect monolithic SLICs (Subscriber Line Interface Circuits) against overvoltages on the telephone line caused by lightning, a.c. power contact and induction. The TISP61521 limits voltages that exceed the SLIC supply rail voltage. The TISP61521 parameters are specified to allow equipment compliance with Bellcore GR-1089-CORE, Issue 1 and ITU-T recommendation K.20. The SLiC line driver section is typically powered from 0 V (ground) and a negative voltage in the region of -20 V to -150 V. The protector gate is connected to this negative supply. This references the protection (clipping) voltage to the negative supply voltage. The protection voltage will then track the negative supply voltage and the overvoltage stress on the SLiC is minimized. Positive overvoltages are clipped to ground by diode forward conduction. Negative overvoltages are initially clipped close to the SLiC negative supply rail value. If sufficient current is available from the overvoltage, then the protector will switch into a low voltage onstate condition. As the overvoltage subsides, the high holding current of TiSP61521 crowbar helps prevent d.c. latchup. These monolithic protection devices are fabricated in ion-implanted planar vertical power structures for high reliability and in normal system operation they are virtually transparent. The TISP61521 buffered gate design reduces the loading on the SLIC supply during overvoltages caused by power cross and induction. The TISP61521 is available in an 8-pin plastic small-outline surface mount package.

• Supports Battery Voltages Down to -150V
• Low 3 mA max. Gate Triggering Current
• High 150 mA min. Holding Current
• Rated for International Surge Wave Shapes

• Protect monolithic SLICs (Subscriber Line Interface Circuits) against overvoltages on the telephone line caused by lightning, a.c. power contact and induction