STMicroElectronics has launched the VNF1248F, an Automotive e-fuse MOSFET controller that’s been designed to deliver fast-acting protection, improved power efficiency and advanced functional safety for modern vehicle systems.

The device is the latest addition to the company’s Sti2Fuse family of intelligent switches.

The VNF1248F reacts within 100 microseconds, significantly faster than traditional wire fuses, helping prevent fault propagation within the vehicle’s electrical architecture. It supports 12V, 24V and 48V boardnets, making it suitable for zonal power distribution, replacing conventional fuses and relays, and serving as an ECU main switch or active supply for always-on circuits in parking mode.

“The VNF1248F combines advanced e-fuse features with enhanced flexibility, enabling power savings and robust protection in automotive functional-safety systems,” STMicroelectronics said in a statement.

The controller introduces Capacitive Charging Mode (CCM) to manage large capacitive loads with high inrush currents. An improved Standby-ON mode delivers up to 600mA while consuming less than 75µA, boosting efficiency when the vehicle is parked and extending battery autonomy. An optional external logic supply pin reduces power consumption by 0.4W in 48V systems, while battery undervoltage shutdown ensures compliance with the LV124 automotive standard.

To meet safety requirements, the VNF1248F includes features that support high ASIL levels under ISO 26262, such as advanced fault detection, fail-safe and limp-home modes, built-in self-tests and a dedicated pin for direct hardware control of the MOSFET gate in case of microcontroller failure.

The device incorporates an SPI interface for communication with a host microcontroller, eliminating the need for external programming components and enabling flexible configuration of settings such as short-circuit latch-off and fuse emulation. On-chip non-volatile Memory stores default configurations to ensure consistent behaviour in failsafe conditions.

STMicroelectronics also offers the EV-VNF1248F evaluation board, which connects directly to the load, power supply and microcontroller, along with a software package providing a graphical interface and firmware for configuration and monitoring.

The VNF1248F is now in production, supplied in a 5mm x 5mm QFN32 package.