Automotive High-Side Power Switch with Intelligent Fuse Protection and SPI Interface
STMicroelectronics has started producing automotive high-side power switches with advanced features like intelligent fuse protection and a serial peripheral interface (SPI) for diagnostic data, which enhances resilience and functional safety. The first device in this new series is the quad-channel VNF9Q20F, which integrates ST’s VIPower M0-9 MOSFET and STi2Fuse technology. The STi2Fuse technology, based on the I2t (current squared through time-to-fuse) principle, reacts within 100µs to shut off the MOSFET if excessive current is detected. Acting as an intelligent circuit breaker, the VNF9Q20F stabilizes boardnet voltage and prevents overheating of PCB traces, connectors, and wire harnesses. It also has a capacitive charging mode that accommodates inrush currents, allowing normal operation with highly capacitive loads.
Designed for modern zonal electrical/electronic architectures, the VNF9Q20F can be used for fuse and relay replacement, ECU isolation, and managing systems active when the vehicle is parked. It offers 64 programmable current-limit values, allowing precise control of overload response. The device includes a 10-bit analog-to-digital converter (ADC) and fault registers, providing detailed diagnostic information and digital current sense feedback. This supports vehicle features such as predictive maintenance. An embedded failsafe mode ensures continued operation in case of a failure or malfunction.
Features:
- Quad-channel high-side power switch
- Integrated VIPower M0-9 MOSFET
- STi2Fuse technology with I2t functionality
- 100µs response time to excessive current
- 64 programmable current-limit values
- 10-bit analog-to-digital converter (ADC)
- Fault registers for diagnostics
- Digital current sense feedback
Applications:
- Fuse and relay replacement
- ECU isolation
- Managing parked vehicle systems
- Zonal electrical/electronic architectures
- Preventing overheating of PCB traces, connectors, and wire harnesses
- Enhancing functional safety in automotive systems
Availability:
The VNF9Q20F is currently in production and comes in a 6mm x 6mm QFN package. It is priced at $2.85 each for orders of 1,000 units.
