The TBU® device from Bourns is a silicon-based, solid-state, resettable device that is placed in series with a signal path. The TBU (transient blocking unit) device operates in approximately 1 µs once line current exceeds the TBU device's trigger current. When operated, the TBU device typically restricts line current to less than 1 mA. When operated, the TBU device will block all system voltages and any other voltages including the surge up to rated limits.

After the surge, the TBU device resets when the voltage across the TBU device falls to the V_reset level. The TBU device will automatically reset on lines that have no DC bias or that have a DC bias below V_reset (such as un-powered signal lines). If the line has a normal DC bias above V_reset, the voltage across the TBU device may not fall below V_reset after the surge. In such cases, special care needs to be taken to ensure that the TBU device will reset, otherwise an automatic or manual power down will be required.

TBU-CA

The TBU-CA series of Bourns TBU products are low-capacitance, single bidirectional high-speed protection components, constructed using MOSFET semiconductor technology, and designed to protect against faults caused by short circuits, AC power cross, induction, and lightning surges.

The TBU high speed protector placed in the system circuit will monitor the current with the MOSFET detection circuit triggering to provide an effective barrier behind which sensitive electronics will not be exposed to large voltages or currents during surge events. The TBU device is provided in a surface mount DFN package and meets industry standard requirements such as RoHS and Pb Free solder reflow profiles.

TBU-DT

The TBU-DT series of Bourns TBU products are very low-capacitance, dual unidirectional high speed surge protection components designed to protect against faults caused by short circuits, AC power cross, induction, and lightning surges.

The TBU-DT series is a unidirectional TBU device; the TBU protector will trip in less than 1 µs when the current reaches the maximum value in one direction only, which is when Pin 1 is positive in voltage with respect to Pin 2 and Pin 4 is positive with respect to Pin 3. No current limiting exists in the opposite polarity, and the TBU device appears as resistive in nature. The reverse current should not exceed the maximum trip current level of the TBU device. An external diode may be used to prevent reverse current in DC biased applications.

TBU-PL

The TBU-PL series of Bourns TBU products are low-capacitance, dual bidirectional high speed protection components, constructed using MOSFET semiconductor technology, and designed to protect against faults caused by short circuits, AC power cross, induction and lightning surges. In addition to over-current protection, an added feature is the voltage monitoring on the two lines. If the voltage on the line drops below V_SS then the voltage will trigger the device to switch to the blocking state.

The TBU high speed protector placed in the system circuit will monitor the current with the MOSFET detection circuit triggering to provide an effective barrier behind which sensitive electronics will not be exposed to large voltages or currents during surge events. The TBU device is provided in a surface mount DFN package and meets industry standard requirements such as RoHS and Pb Free solder reflow profiles.