estm-st-banner estm-st-banner estm-st-banner-mobile

Electronic digitally resettable fuses for use in digitalized power distribution.

Traditional fuses act as a 'safety wire'. When too much current flows through a circuit, thermal energy is generated and melts the fuse wire. This instantaneously cuts the circuit. However, fuses can sometimes survive a sudden short surge of current without rupture, and that value is part of the fuse's rating. However, that surge might cause damage to sensitive electronic components.


Silicon fuses, also called eFuses, can quickly detect these overcurrent events and ensure protection in a far more predictable manner. ST's proprietary STi²Fuse technology provides superior fast-acting, resettable, and reliable over-current protection.

ST's proprietary STI²Fuse technology provides superior fast-acting, resettable, and reliable over-current protection.


STi²Fuse intelligent switches also help simplify vehicle wiring harnesses and reduce weight by eliminating user-accessible fuse boxes and the associated cabling and installation overheads.


The savings in weight contribute to improving vehicle performance, including extended driving range and reduced CO2 emissions.

Benefits of STi²Fuse versus standard melting fuses

  • Up to 20% weight reduction
  • Much faster reaction time
  • Smaller wire harness size
  • Ability to manage and distribute multiple sources of energy
  • Tolerance to fault, making the solution ideal for autonomous driving
  • Advanced device health monitoring and improving predictive maintenance

STi²Fuse family of intelligent fuses

The new STi²Fuse family integrates I²-t protection. The formula I²-t defines the changes in thermal energy inside a fuse or cable as current (I) flows against time (t).
STi²Fuse products include a digital interface to boost efficiency and reliability in the latest automotive zonal electronic/electrical (E/E) architectures. They also support greater electrification and additional functions for smart driving.

  • Wire gauge and harness optimization
  • Low number of external components
  • Low complex MCU
  • Space saving
  • Easy and flexible software design
  • Hardware coded failsafe management
  • Permanent supply operation through standby ON management
  • Compliant with ASIL-B requirements from a functional safety perspective

Learn more about STi²Fuse

Learn more about this new approach to circuit protection and switching in automotive architectures. Download our whitepaper to discover our new family of intelligent electronic fuses, STi²Fuse, designed to assist car manufacturers and OEMs in the journey ahead.