Bourns TBUSeries circuit protectors feature broad range of trigger currents & voltages

Riverside, Calif. - The Transient Blocking Unit (TBU) Series of circuit protection devices from Bourns, Inc., are designed to protect a broad selection of industrial and telecommunications applications. The new series provides ultra-fast overcurrent protection offered in a wide range of trigger currents and voltages and reduced form factors to save board space. Designated the Bourns TBU-CA Series, the new devices are electronic current limiters (ECL) that are triggered by excessive voltage or current.

Designed as an optimal circuit protection solution for industrial controls, medical electronics, automated test systems, and military and aerospace applications, the Bourns TBU-CA Series can be used for protection on Ethernet, RS-485, HART and other ports where dangerous surge and power cross events may occur. The series can also be used in telecom applications and provides a barrier to surges while allowing high frequency signals such as VDSL2 to pass through without damage to the circuit.

The Bourns TBU-CA Series eliminates the need for large shunt protection devices by stopping the damaging currents from reaching protected circuits in less than one microsecond. The new devices are low capacitance, single bidirectional, high speed devices designed to protect against faults caused by short circuits, AC power cross, induction and lightning surges within rated limits. The devices are resettable and feature significantly lower let-thru energy and overshoot protection, which reduces stress on the printed circuit board (PCB) for increased reliability and product life.

“Higher data rates combined with more sensitive electronics presents a real challenge for protection engineers,” said Paul Wiener, telecom market director at Bourns. “Bourns’ TBU protection technology limits the energy allowed into sensitive electronics without loading high data rate lines with capacitance. This allows designers to place high performance protection on even their highest bandwidth applications.”

Bourns’ TBUHigh Speed Protector is the first new approach to electronics circuit protection in over a decade. This technology is designed to block a transient through a current disconnecting mechanism. Rather than a complex interstage coordination between two shunting components, the TBUdevice allows customers to protect circuit boards from both overvoltage and overcurrent surges. The TBU device protects electronic equipment within nanoseconds, essentially eliminating latency common in the circuit protection design, limiting let-through energy.

The TBUdevice has virtually no capacitance or inductance, and therefore can be used in high bandwidth applications. It has a resistive characteristic which permits currents up to a certain level to pass unimpeded to the protected interface. In higher current situations, the TBUdevice switches to a high impedance state, protecting until the surge voltage dissipates or the short-circuit reseals. The TBUdevice offers full bi-directional operation, which is inherently resettable.

The Bourns TBU-CA Series is available in five impulse blocking voltages from 250V to 850V with minimum trip currents of 50 mA to 500 mA featuring resistance values as low as 3 ohms. Product samples, evaluation boards and sample kits are available now through Bourns’ distribution partners. As a pricing example, Bourns TBU-CA085-500-WH is priced at $.69 each in 10K quantities. For more information visit www.bourns.com.