STMicroelectronics has introduced the STEF01 programmable electronic fuse, which can sustain up to 4A of continuous current over a wide operating input voltage range from 8V to 48V while reducing insertion loss thanks to the integration of low-RDS(ON) VIPower™ MOSFETs. This enables fast overload protection in high-power applications.

STEF01 can be connected in series with the main power rail to protect the load from overcurrent and overvoltage. The voltage is fixed to a user-defined maximum value, which can be preset using an external resistor.

It can control the internal power MOSFET to limit the transient current to the programmed safe tolerance limit, and if a strong overcurrent or short circuit is detected, it drops the current to the lowest allowable limit and maintains it.
The STEF01 utilizes ST's BCD8 high-voltage process and includes various value-added features, such as dV/dt control to prevent excessive inrush current during power-on or hot-swap insertion.

This allows the rise time of the output voltage to be delayed by at least 3 ms, which can be increased by connecting an external capacitor if required. Additionally, programmable UVLO (Under-Voltage Lockout), configurable using external components, allows for fine-tuning of the desired minimum voltage rail value to suit load requirements.

It also includes overtemperature shutdown with latching or auto-retry, as well as maximum dissipated-power protection to prevent damage to the STEF01 from unusually high voltages when powered up by excessive capacitive loads, short-circuits at high voltages, or overload transients.

It also has an Enable/Fault pin that can be used for status monitoring or device control, along with a Power-Good indicator. A dedicated gate-driver output for controlling an external PMOS switch simplifies implementation of reverse-current protection.

The STEF01 provides flexible and convenient protection in a wide range of applications, including industrial hot-swap boards and control equipment, circuit breakers, power buses, security or systems, telecom power modules, or distributed power systems.

The STEF01 is available now in a 14-pin HTSSOP14 package, priced from $1.00 for orders of 1,000 pieces. For more information, visit www.st.com/stef01-pr.