Bourns's MF-PSMF series of PTC resettable fuses come in a standard 0805 package. The MF-PSMF is an excellent choice for short circuit and overcurrent protection in 5V applications. The MF-PSMF series operates as a fuse. It begins with a very low impedance and can be driven to high impedance by an overcurrent condition or an increase in ambient temperature. Unlike typical single blow fuses, the MF-PSMF series can be reset by cycling the power onoff.