High-speed fuses are typically used with power semiconductor devices. Why is this? Power semiconductors combine high-power handling and fast switching capability in a small package size. These devices generate excessive heat during their normal operation and have low thermal withstand capacity. Additionally, any reduction in size impacts the device’s ability to withstand overcurrent and overvoltage. This causes the device to require additional arrangements such as heat sinks and/or forced air/liquid cooling to dissipate the heat and help it run cool. To prevent this, a protective circuit device is needed, one of the fastest being a high-speed fuse. High-speed fuses have proven to be the devices that offer the proper level of protection to these sensitive power semiconductor devices. The fuse should limit the energy through the semiconductors during a fault to avoid case rupture, and in case of capacitor short circuit, avoid explosion of the device.