Programmable MOSFET fuse handles 4A up to 48V
The STEF01 can handle continuous current up to 4A over a wide operating input-voltage range of 8V to 48V, with low insertion loss from the integrated low-RDS(ON) VIPower MOSFET. The fuse is aimed at 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.
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 falls back to a lower limit if a strong over-current or short-circuit is detected.
The STEF01 uses ST’s BCD8 high-voltage process to integrate additional 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. The programmable Under-Voltage Lockout (UVLO) is set using external components to fine tune the desired voltage rail minimum value for the load requirements.
Other features include thermal shutdown with latching or auto-retry, and maximum dissipated-power protection, which prevent power surges from damaging the device 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 the implementation of reverse-current protection designs.
The STEF01 is available now in a 14-pin HTSSOP14 package, priced from $1.00 for orders of 1000 pieces.