They are ideal for protecting loads and subsystems from anomalies such as overcurrent, overvoltage, and overtemperature, ensuring reliable operation and safeguarding sensitive components in automotive lighting and body controls, such as door locks and power windows. Extensive diagnostic functions, including open circuit and battery reversal detection, further enhance safety and reliability.
(Fig. 1)
Vehicle electronic control systems are becoming increasingly sophisticated with the advancement of autonomous driving and electric vehicles (EVs). This evolution has underscored the importance of electronic protection from a functional safety perspective, driving the shift towards a zonal controller architecture that manages vehicle functions in designated zones. As a result, the use of smart switches for electronic load protection and control is growing rapidly.
Zone controllers must each manage a large number of loads, but conventional smart switches often lack the driving capacity required for high-capacity loads. ROHM's new smart switches address this challenge, offering key performance attributes such as low conduction resistance and high inductive power limiting capacity, while significantly improving the driving capacity of capacitive loads. By bringing high-performance smart switches to market tailored to the requirements of zone controllers, ROHM is contributing to the electrification of the automotive industry and the elimination of mechanical fuses.
The new products feature exceptional high-capacity load driving capability, maximizing performance at the critical interface between zone controllers and output loads (including multiple ECUs). Leveraging proprietary, state-of-the-art process technology, both low driving resistance and high inductive power limiting capability are achieved—two characteristics that typically require trade-offs. The result is a balanced integration of three key performance parameters: drive capability, driving resistance, and power tolerance. This enhances the safety, efficiency, and reliability of the system design. The devices also incorporate a best-in-class*, high-precision (±5%) current sensing function, providing effective protection for harnesses connected to output loads. Simultaneously, the compact, high-heat-dissipation HTSOP-J8 package ensures excellent design versatility.
Looking ahead, ROHM remains committed to improving safety and energy efficiency in the automotive sector by developing high-reliability, high-performance devices.
(Fig. 2)
New product range (high-side smart switches with current detection)
(Fig. 3)
Application examples:
Bodywork applications, propulsion systems/inverters, other switch-related circuits
