Bourns TBU® High-Speed Protectors

Bourns® TBU® high-speed protectors are circuit protection devices constructed using MOSFET semiconductor technology. When placed in series in the system, the TBU® protector monitors the current flowing through the line. If the current exceeds a preset level, the TBU® device triggers, providing an effective barrier to large, destructive voltages or currents during surge vents, thereby protecting sensitive electronics. The TBU® device operates in approximately 1 μs - once line current exceeds the TBU® device’s trigger current Itrigger. When operated, the TBU® device restricts line current to less than 1 mA typically, and blocks voltages including the surge up to rated limits. After the surge, the TBU® automatically resets itself when the voltage across the TBU® device falls to the Vreset or below. Therefore, the TBU® device will automatically 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; software monitoring may be used to accomplish this task.