The TBU™ device, constructed using MOSFET semiconductor, placed in system circuit will monitor the current with the MOSFET detection circuit triggering to provide an effective barrier behind which sensitive electronics are not exposed to large voltages or currents during surge events. The TBU™ device responds in less than 1 µs, once line current exceeds the TBU™ device’s Itrigger (trigger current) point. When operated, the TBU™ device restricts line current to less than 1 mA typically and the TBU™ device will block surge voltages.
After the surge transient dissipates, the TBU™ device resets when the voltage across the TBU™ device falls below the Vreset level. The TBU™ device will always reset on lines which have no DC bias or have DC bias below Vreset (such as unpowered signal lines). If the line has a normal DC bias above Vreset, the voltage across the TBU™ device may not fall below Vreset after the surge. In such cases, special care needs to be taken to ensure that the TBU™ device will reset, with software monitoring as one method used to accomplish this. Bourns application engineers can provide further assistance.
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 and are available in six families: TBU-CA, TBU-PL, P40, P-G (P500-G, P850-G), C (C650 and C850), and P-U (P650-U and P850-U).