STMicroelectronics STEF01 programmable electronic fuse

Click2Contact

Sustaining up to 4 A continuous current over a wide operating input-voltage range of 8 to 48 V, with low insertion loss due to its integrated low-R_DS(ON) VIPower MOSFET, the STEF01 programmable electronic fuse from STMicroelectronics extends the benefits of fast-acting overload protection to applications at high power ratings.

When connected in series to the main power rail, the product protects the load against overcurrent and overvoltage. The voltage is clamped to a user-defined maximum, preset with external resistors. Excessive current is restricted to the programmed safe limit by controlling the internal power MOSFET and folds back to a lower limit if a strong overcurrent or short-circuit is detected.

The device leverages ST’s BCD8 high-voltage process to integrate features including dV/dt control to prevent excessive inrush current during start-up or hot-swap insertion. This slows the output-voltage ramp-up time to at least 3 ms, which can be increased if desired by connecting an external capacitor. Programmable undervoltage lockout (UVLO), also set using external components, allows the user to fine-tune the desired voltage-rail minimum value to suit the load requirements.

Further features include thermal shutdown with latching or auto-retry, and maximum dissipated-power protection. These prevent exceptionally high power from damaging the fuse when starting up into heavy capacitive loads or during large load transients or short-circuits at high voltage. There is also a power-good indicator and an enable/fault pin that can be used as either a status monitor or to control the device. A dedicated gate-driver output for controlling an external N-channel MOSFET simplifies implementation of reverse-current protection.

The product delivers flexible and convenient protection for a wide range of applications, including industrial hot-swap boards and control equipment, circuit breakers, power buses, security or lighting systems, telecom power modules or distributed power systems.

For more information: www.st.com/stef01-pr.