ROHM's automotive camera module optimizes ADAS system solutions

Assisted driving (with the ultimate goal of autonomous driving) has become an important trend in the development of automobiles. ADAS systems are built by combining devices with different sensing methods and sensing distances, such as LiDAR, sonar, and cameras. Among them, in units such as parking assist systems, since on-board cameras play an important role in eliminating nearby blind spots, the latest cars are equipped with about 10 cameras per car. In addition, as ADAS continues to develop, its use is also further increasing, which has also put forward higher requirements for improving the performance of various cameras. On the other hand, as the number of cameras installed increases, the power that can be supplied by the battery and the space for installing the camera are limited. Therefore, in the on-board camera module, the demand for further reducing the size of the circuit board and reducing power consumption is increasing.

Recently, ROHM, a world-renowned semiconductor manufacturer, has developed the SerDes IC "BU18xMxx-C" and the PMIC "BD86852MUF-C" for automotive camera modules that are very suitable for ADAS (Advanced Driver Assistance System) . These two products not only meet the needs for miniaturization and low power consumption of modules, but also help reduce customers' development hours due to their low electromagnetic noise (low EMI) characteristics. With these two new products, ROHM has strengthened its competitive advantage in automotive camera modules in ADAS systems and can provide customers with more advanced automotive camera solutions. In particular, both products meet the ASIL-B level active safety standards.

Automotive semiconductor devices and system solutions are one of the key businesses of Rohm Semiconductor. Rohm provides a wide range of products and solutions for the new generation of automobiles, targeting automotive devices according to different applications, including automotive motors, LED lamp drivers, graphics chips, networks, PMIC for cameras, ADAS systems, overall solutions for LCD devices, SerDes IC for displays, and SerDes IC for cameras, etc.

Li Chunhua, deputy general manager of the Technology Center of Rohm Semiconductor (Shanghai) Co., Ltd., introduced that in view of the trend of increasingly miniaturized vehicle cameras, the size of ordinary camera modules can now be as small as 2×2×2cm. In such a small space, it is necessary to accommodate the CMOS image sensor, as well as the camera, power management PMIC, power supply, serializer, etc. for power supply, which requires very high size. In response to such a trend and the requirement of miniaturization, Rohm launched the SerDes IC "BU18xMxx-C" and PMIC "BD86852MUF-C", which can effectively make the size of vehicle cameras smaller and power consumption lower.

The SerDes IC "BU18xMxx-C" used to transmit images can optimize the transmission rate according to the resolution, so the power consumption can be reduced by 27% compared with ordinary products. In addition, the EMI peak can be reduced by about 20dB through the transmission rate optimization function and the spread spectrum function. Not only that, the IC also has a freeze detection function that can detect the frozen state of the image, thereby improving the reliability of the entire ADAS system. Li Chunhua introduced that the characteristics of the SerDes IC "BU18xMxx-C" are mainly reflected in the optimization of the transmission rate, which helps to reduce the power consumption of the vehicle-mounted camera module; at the same time, the built-in transmission rate optimization function and the spread spectrum function help to reduce the design time of EMI countermeasures; in addition, the freeze detection function helps to improve reliability, and the new product series lineup is complete, supporting various CMOS image sensors and SoCs.

The BD86852MUF-C, a PMIC (power management IC) for cameras, provides better management functions for the power supply system of CMOS image sensors from major manufacturers. Since voltage setting and timing control can be performed with just a single IC, the mounting area can be reduced by approximately 41%, contributing to the miniaturization of automotive camera modules. In addition, since the circuit structure can disperse the heat concentrated on the PMIC for the camera, a high conversion efficiency of 78.6% is achieved by suppressing heat generation, which helps to further reduce power consumption. In addition, the new product has a spread spectrum function, which helps reduce the design time for EMI countermeasures, and has a built-in power supply system that is ideal for camera modules to ensure high reliability.