Bourns MF-USML/X Low Ohmic PPTC Resettable Fuses

Bourns MF-USML/X Series are resistance surface mount Polymer Positive Temperature Coefficient (PPTC) resettable fuses with a 12V rating. The low ohmic series utilizes Bourns freeXpansion™ design, which increases the performance of the resettable fuse with higher hold currents (Ihold), higher voltages (Vmax), improved resistance stability, and a smaller footprint. The fuses can now achieve 5.5A Ihold at 12VDC and current ratings of 1.75A to 5.5A in a space-saving 1210 package. Model MF-USML/X fuses are ideal for Li-ion battery packs, motherboards, and portable consumer electronic I/O port protection. The series is designed to protect against both overcurrent and overtemperature events within the designated specifications.


  • Surface mount packaging for automated assembly
  • Small footprint size (1210) and low profile for space-constrained mobile applications
  • Ultra-low resistance
  • Higher withstanding voltage
  • RoHS compliant and halogen-free


  • Li-ion battery pack protection
  • Power delivery port protection
  • Higher voltage withstand
  • PC motherboard plug-and-play protection
  • Mobile phone battery and charging protection
  • USB port protection
  • Game console port protection


  • 1.75A to 5.5A current rating
  • 5.5A Ihold at 12VDC
  • -40°C to +85°C operating temperature range
  • 1210 package
Published: 2019-04-11 | Updated: 2023-03-20