High power electronic fuse with features for safety

When connected in series to the main power rail, the STEF01 protects the load against over current and over voltage. 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 over current or short circuit is detected.

The STEF01 leverages ST’s BCD8 high voltage process to integrate value added features, including dV/dt control to prevent excessive inrush current during startup or hot swap insertion. This slows the output voltage ramp-up time to at least 3ms, which can be increased if desired by connecting an external capacitor. Programmable Under-Voltage Lockout (UVLO), also set using external components, aims to allow 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, which each prevent exceptionally high power from damaging the STEF01 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 STEF01 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.