TISP61089BDR-S

The Bourns TISP61089BDR-S is a dual forward-conducting buffered P-gate thyristor overvoltage protector designed for protecting monolithic SLICs against overvoltages on telephone lines caused by lightning, AC power contact, and induction. The device limits voltages that exceed the SLIC supply rail voltage. Parameters are specified to allow equipment compliance with Telcordia GR-1089-CORE and ITU-T recommendations K.20, K.21, and K.45. The low gate triggering current below 5mA enables voltage tracking with the SLIC battery voltage. The high holding current of 150mA minimum prevents false latch-up during normal operation.

The TISP61089BDR-S operates as a voltage-tracking thyristor protector with three key mechanisms: 1) Gate Tracking: The gate terminal is connected to the SLIC battery voltage, establishing the protection threshold relative to the supply rail. When the line voltage exceeds the gate voltage by the breakover margin, the thyristor fires. 2) Crowbar Protection: Upon triggering, the thyristor enters a low-impedance crowbar state, diverting surge current away from the SLIC. The 30A peak pulse current rating provides robust protection against lightning-induced surges. 3) Self-resetting: After the surge subsides and the current drops below the 150mA holding current, the thyristor automatically returns to the high-impedance blocking state, restoring normal line operation.

• SLIC overvoltage protection in VoIP gateways and line cards
• Telecom central office equipment surge protection
• PBX systems meeting GR-1089-CORE compliance