Effective circuit protection improves the safety and reliability of your electronics applications. Here’s a look at some of the newest circuit protection devices on the market.
TVS Diode Arrays
Electrostatic discharge (ESD) remains a key issue in many electronic designs. Three series of transient voltage suppressor (TVS) diode arrays from Littlefuse, though, have their sights set on this problem.
First, the SP3012 series expands the company’s SPA family, which provides ESD protection for high-speed ports such as USB 3.0 (Fig. 1). The series offers an extremely low capacitance loading of only 0.5 pF while providing ESD protection of ±12 kV, exceeding the maximum level specified in the IEC61000-4-2 international standard.
The SP3012 also provides market-leading clamping performance due to its low dynamic resistance of only 0.4 ?, according to the company, which reduces the peak voltage seen by the chipset by as much as 80% in some cases.
Furthermore, the SP3012 benefits the board designer by allowing the traces to be routed directly underneath the device, simplifying printed-circuit board (PCB) design. The µDFN-10 package measures 2.5 by 1.0 by 0.5 mm, making it ideal for equipment that uses USB 3.0, such as external hard-disk drives, set-top boxes, notebooks, smart phones, digital cameras, and MP3/PMP players.
The SP4061 and SP4062 series, meanwhile, protect high-speed ports such as 10/100/1000 Ethernet and T3/E3 interfaces that may experience damage due to ESD and nearby lightning strikes (Fig. 2). Their respective 2.5- and 3.3-V standoff voltages accommodate the most typical physical-layer (PHY) voltages being used today.
Both devices are particularly suitable for protecting Ethernet ports in public branch exchange (PBX) systems, Voice over Internet Protocol (VoIP) phones, set-top boxes, switches, and any other customer premises equipment (CPE).
What’s more, the products’ robust surge protection and low clamping voltages help equipment manufacturers comply with regulatory standards such as GF-1089, ITU, and YD/T, extending equipment life and maximizing reliability, the company says.
TE Circuit Protection’s 2410SFV family of 20 ac-dc fuses boasts current ratings from 0.5 to 20.0 A. These 2410 fuses help provide secondary-side circuit protection, conserve board space, and reduce design costs in a variety of high-voltage, high-current designs. Typical applications include home appliances (LCD TV LED backlighting, LCD TV CCFL backlighting), LED lighting, office automation, and industrial and medical equipment.
Available in an ultra-thin (6.1 by 2.5 mm) surface-mount device (SMD) package, these fuses offer I2t characteristics (DCR) from 0.0034 to 0.231 ? and a high-interrupt current from 50 to 300 A. Rated for operation at high temperatures ranging from –55°C up to 125°C, the fuses’ ability to withstand high-inrush current minimizes nuisance tripping during transient overload conditions.
The UMF 250 surface-mount fuse from Schurter protects electronic systems from overcurrents and short circuits. Offered in five rated currents from 500 mA to 10 A, it features a high breaking capacity of up to 200 A at rated voltage. Within the UMF 250, both primary and secondary protection on SMD PCBs is possible.
Applications include protection of power supplies, medical equipment, and devices for home and industrial use. The fuse also complies with the European Union’s Restrictions on Hazardous Substances (RoHS). And, it can be used with lead-free soldering processes.
Toggle Circuit Breaker
Carling’s MS-Series sealed toggle circuit breaker was designed and tested to operate in harsh environments. Ideally suited for commercial off-the-shelf (COTS) military applications, it features a durable metal and sealed mounting bushing with MIL-PRF-39019F ingress protection when mounted in a panel.
The device also was designed in accordance with MIL-PRF-55629 and MIL STD 202, making it ideal for applications that require resistance to shock, vibration, moisture, salt spray, and thermal shock. Its compact size and reliability suit it for ruggedized communication equipment and other mission-critical equipment as well.
Surge-Trap Type 1 SPD
Mersen touts its Surge-Trap Type 1 surge protective device (SPD) as a fail-safe and economical solution for applications that require a NEMA-style SPD. The product is UL 1449 3rd edition approved and offers a wide range of voltage configurations to meet all needs in its class. It also features Mersen’s patented TPMOV technology, eliminating the need for additional overcurrent protection.