New smart switches optimised for zonal controllers

ROHM has developed six new high-side Smart Switches (Intelligent Power Devices, abbreviated as IPDs) in the BV1HBxxxEFJ series (BV1HB008EFJ-C, BV1HB012EFJ-C, BV1HB020EFJ-C, BV1HB040EFJ-C, BV1HB090EFJ-C, BV1HB180EFJ-C) with highly accurate current sensing capability and ON resistances ranging from 9mΩ to 180mΩ. They are excellent for protecting loads and subsystems from abnormalities such as overcurrent, overvoltage, and overtemperature, thereby ensuring reliable operation and safeguarding sensitive components in automotive lighting and body control systems, including door locks and power windows. Extensive diagnostic capabilities, such as open load and reverse battery detection, further enhance safety and reliability.

Vehicle electronic control systems are becoming increasingly sophisticated with the advancement of autonomous driving and EVs. This evolution has heightened the importance of electronic protection from a functional safety standpoint, driving the shift toward a zonal controller architecture that manages vehicle functions in designated zones. As a result, the usage of smart switches for electronic load protection and control is rapidly growing.

Zonal controllers must each manage many loads, but conventional smart switches often lack the drive capability required for high-capacitance loads. The company's new smart switches manage this challenge, delivering key performance attributes such as low ON resistance and high inductive energy clamp while greatly improving capacitive load drive capability. By commercialising high-performance smart switches tailored to the requirements of zonal controllers, the company is contributing to automotive electrification and the elimination of mechanical fuses.

The new products feature exceptional high-capacitance load driving capability, maximising performance at the critical interface between zonal controllers and output loads (including various ECUs). Employing proprietary cutting-edge process technology makes it possible to achieve both low ON resistance and high inductive energy clamp – two characteristics that typically involve a trade-off. The result is a well-balanced integration of three key performance metrics: drive capability, ON resistance, and energy tolerance. This improves system design safety, efficiency, and reliability. The devices also incorporate a best-in-class high-precision current sensing function (±5%) that supplies effective protection for harnesses connected to output loads. At the same time, the compact, high-heat-dissipation HTSOP-J8 package provides excellent design versatility.