Bourns Transient Blocking Unit (TBU) electronic current limiters (ECL) are circuit protection devices triggered by excessive voltage or current and designed as an optimal circuit protection solution for industrial controls, medical electronics, automated test systems, and military and aerospace applications. They are low capacitance, single bi-directional, high speed, resettable devices which protect - within rated limits - against faults caused by short circuits, AC power cross, induction and lightning surges. Special features include ultra-fast over current protection, in a wide range of trigger currents and voltages, and reduced form factors to save board space. The TBU can be used for protection on Ethernet, RS-485, HART and other ports where dangerous surge and power cross events may occur. It can also be used in telecom applications, providing a barrier to surges while allowing high frequency signals such as VDSL2 to pass through without damage to the circuit. For sensitive electronics applications the TBU eliminates the need for large shunt protection devices by stopping - in less than one microsecond - the damaging currents from reaching protected circuits. The TBU also offers significantly lower let-through energy and overshoot protection, which reduces stress on the PCB for increased reliability and product life. Bourns TBU protection technology limits the energy allowed into sensitive electronics without loading high data rate lines with capacitance. This enables designers to place high performance protection on even their highest bandwidth applications.

Superior circuit protection
Overcurrent and overvoltage protection
Blocks surges up to rated limits
High speed performance
Small SMT package
Operating temperature range -40°C to +125°C
Storage temperature range -65°C to +150°C
Maximum junction temperature +125°C
ESD: IEC 61000-4-2

UL

UL

Surface Mount Technology

Resettable fuses are designed for the protection of electrical and electronic circuits against excessive currents. They switch rapidly from a low resistance to very high resistance state under electrical overload or short circuit conditions, and feature automatic reset and return to low resistance state when fault condition ceases and power is removed.

Maintenance free automatic reset for thousands of cycles
Small size and no fuseholder required

Main applications

Security systems
Power supplies and transformers
Power switching devices
Automotive and medical equipment
Instrumentation and control
Computers and peripherals
Audio visual and telecommunications