A new generation of automotive smart switches is raising the bar for zonal controllers, combining high-capacitance load drive, precise current sensing, and built-in diagnostics to replace mechanical fuses and boost safety in electrified vehicles.
ROHM has introduced a new lineup of high-side smart switches designed specifically for zonal controllers in modern vehicles. The BV1HBxxxEFJ series—featuring six variants with ON resistances ranging from 9 mΩ to 180 mΩ—brings advanced load protection, precise current sensing, and robust driving capability to meet the demands of automotive electrification.
The devices stand out for their ability to handle high-capacitance loads, a key challenge in zonal architectures where multiple subsystems must be managed from a single controller. By combining low ON resistance with high inductive energy clamping, the switches strike a balance between drive performance, energy tolerance, and thermal management—traits that are often difficult to integrate in a single device. ROHM claims the new series sets a benchmark with ±5% current sensing accuracy, enabling effective harness protection and safer system-level operation.
The key features are:
- Replaces mechanical fuses with smart load control
- Adds diagnostics: open-load, reverse battery, overtemperature
- Compact HTSOP-J8 package design
- Strong heat dissipation for tight spaces
Zonal controllers are fast replacing traditional distributed ECU systems as automakers transition to architectures that consolidate vehicle functions into defined zones. This shift is driven by the rise of EVs and advanced driver assistance systems (ADAS), both of which demand higher reliability and functional safety. Typical use cases include lighting modules, door locks, power windows, and other body electronics, as well as broader applications in powertrain and inverter systems.
By tailoring its new IPDs for zonal controllers, ROHM positions itself as a key enabler of automotive electrification. The series enhances both design efficiency and long-term reliability while supporting the industry’s move toward software-defined, fuse-free vehicle platforms.
