This surface mount Polyfuse® family of polymer-based resettable fuses provides reliable overcurrent protection for a wide range of OEM products such as computer motherboards, USB hubs & ports, CD/DVD drives, PDA's, digital cameras and battery packs. Each of these Polyfuse® Series' features low voltage drops and fast trip times while offering full resettability. This makes each an ideal choice for protection in datacom and battery-powered applications where momentary surges may occur during interchange of batteries or plug & play operations.

The SMD0805, with the industry's smallest footprint, measuring only 2.2mm by 1.5mm, features four hold current ratings from 100mA to 500mA with a current interruption capability of 40A at rated voltage. Both the SMD1206 and SMD1210 Series are optimized for protection of computer peripherals, PC Cards and various I/O port types. All ratings offered comply with the UL 1950 Information Technology Equipment standard which requires that the maximum current available to the connector must be limited to 8 Amps in less than 60 seconds. The misconnection of 5 Volt and 12 Volt power lines between a disk drive and host computer can cause reverse polarity or inrush faults which may lead to failure of the disk drive capacitors. The SMD1812 prevents this fault condition by latching into it's high resistance state until the connections can be properly installed. Hold current ratings are available up to 2.6 Amps with very quick trip times - as low as 150ms.

The Polyfuse® is actually a positive polymeric temperature coefficient (PPTC) device consisting of conductive carbon black particles. Under normal operating conditions, strings of carbon particles conduct current while exhibiting a very low internal resistance. When the Polyfuse's® trip or fault current is exceeded, the particle strings break up and disburse randomly followed by a rise in internal component resistance of several orders of magnitude. This rapid increase in resistance limits current flow to nearly zero effectively protecting the downstream circuitry. When the fault subsides or power is removed, the Polyfuse® cools and resets returning to it's pre-tripped state.

The Polyfuse® family is actually a positive polymeric temperature coefficient (PPTC) device consisting of conductive carbon black particles. Due to the automatic resetting of the Polyfuse, these components are ideal for applications, where temporary fault conditions (e.g. during hot plugging) can occur. Under normal operating conditions, strings of carbon particles conduct current while exhibiting a very low internal resistance. When the Polyfuse's® trip or fault current is exceeded, the particle strings break up and disburse randomly followed by a rise in internal component resistance of several orders of magnitude. This rapid increase in resistance limits current flow to nearly zero effectively protecting the battery pack circuitry. When the fault subsides or power is removed, the Polyfuse® cools and resets returning to it's pre-tripped state, and normal equipment operation can resume. The radial leaded RLD-USB - Series 709 is specifically designed for Universal Serial Bus (USB) applications with lower resistance, faster trip times and lower voltage drops.

This low profile strap-type Polyfuse® family of resettable fuses provides thermal and overcharge protection for rechargeable battery packs commonly used in portable electronics such as mobile phones, notebook computers, PDA's, and camcorders.

Both Li-Ion and NiMH pack designs are enhanced with a 0.8mm high form factor on the VTD - 719 Series. It's nickel terminals can be welded directly to the battery cells with no increase in pack height. As the requirement for extended battery run-times increases in computers and cameras, designers can take advantage of the higher 7.3 Amp hold current capability of the LRD - 718 Series. It's low internal resistance guarantees longer battery runtimes and lower system voltage drops. This enables the engineer to design high performance battery powered systems. The LTD - 717 Series is optimised for prismatic packs and exhibits faster trip times - down to 2.9 sec at five (5) times the fuse's hold current rating.

The Polyfuse® family is actually a positive polymeric temperature coefficient (PPTC) device consisting of conductive carbon black particles. Under normal operating conditions, strings of carbon particles conduct current while exhibiting a very low internal resistance. When the Polyfuse's® trip or fault current is exceeded, the particle strings break up and disburse randomly followed by a rise in internal component resistance of several orders of magnitude. This rapid increase in resistance limits current flow to nearly zero effectively protecting the battery pack circuitry. When the fault subsides or power is removed, the Polyfuse® cools and resets returning to it's pre-tripped state.