A new round of global technological and industrial revolution is coming quietly. Electrification, networking, intelligence and sharing have become the development trend and trend of the automobile industry. Driven by the new four modernizations of automobiles, the automobile electronic and electrical architecture has gradually evolved from the original distributed architecture to the cross domain centralized architecture and the vehicle centralized architecture. The automobile electronic software architecture has been continuously upgraded, and the software and hardware are layered and decoupled. The era of software defining automobiles is coming. With the acceleration of automobile intellectualization, China's new energy vehicle market is improving, the carrying rate of ADAS functions is rising, L2 is becoming the standard configuration, and L3 is starting to be mass produced.

Functional safety becomes the focus of the industry under the trend of automobile intelligence

With the promotion of automobile intelligence and the rapid change of automatic driving technology innovation, safety has become the focus of the industry. There are two kinds of safety, one is intrinsic safety, the other is functional safety. Intrinsic safety is a method to ensure safety by eliminating dangerous causes; Functional safety is a method to ensure safety by reducing risks to an acceptable level through functional efforts. Intrinsic safety can ensure absolute safety, but the cost is often high; In contrast, the cost of functional safety is low, but the design must consider how to ensure safety when additional functions fail.

For example, at railway and road intersections, if the method of building overpasses is used to separate the railway from the road and physically avoid the collision between trains and cars, it is an intrinsically safe idea. However, if alarms and railings are set at the intersection of roads and railways, and sensors are installed on the railways, when the sensors detect that trains are approaching, the alarms will sound and the railings will be lowered; when other sensors detect that trains have passed, the alarms will stop and the railings will be raised, although the roads and railways are still physically crossed, However, the risk of collision between cars and trains can be reduced to an acceptable level by setting railway crossings, which is the idea of functional safety. Of course, in this case, if the sensor is damaged, the alarm and railing will not work when the train is approaching, which is a "dangerous" state. Therefore, it is necessary to add the self diagnosis of the sensor or the redundancy design of dual sensors to ensure that the design of a dangerous state will not be triggered even if the sensor is damaged. This is the idea of Fail Safe.

It can be seen that functional safety is actually a design based on the idea of "people will make mistakes" and "things will be damaged". Functional safety usually takes into account both "systematic failure" and "random failure" to ensure that there is no systematic bug and that random failure will not cause harm to people. In China, ISO 26262 (functional safety) has been included in the recommended national standard, and the first Chinese version of ISO 26262, GB/T 34590, has been implemented since May 2018.

Of course, not only the automotive industry has this requirement, but also many industrial scenarios have very high requirements for safety. In order to build a safer system, it is necessary to consider how to ensure safety in case of problems during equipment development, which means that fault safety and functional safety run through the whole process of equipment development.

Reset IC to ensure the safety of automobile and industrial equipment

When it comes to the requirements of automobile and industrial application scenarios for equipment safety, we have to mention the importance of monitoring the system power supply voltage. Reset IC is one of the indispensable products in the voltage monitoring circuit, and has been widely used in EV/HEV inverter, engine control unit, ADAS, automobile navigation system, automobile air conditioner, FA equipment, measuring instruments, servo system In various vehicle and industrial equipment applications that require voltage monitoring of electronic circuits, such as various sensor systems.

In response to the market demand, Rom launched more than 1000 reset ICs. In 2021, it created an annual shipment record of 250 million pieces in the wide application field of low voltage range. Just recently, Rom has also developed a window reset IC "BD48HW0G-C" with high precision, ultra-low power consumption and support for 40V voltage.