The board is a power tree solution for automotive infotainment and ADAS ECUs, with an eight-circuit power tree and built-in DC/DC converters for power supply.
As efforts to prevent automobile accidents and advanced autonomous driving have grown in recent years, the significance of advanced driver-assistance systems (ADAS) that adhere to a high Automotive Safety Integrity Level (ASIL) has surged. Precise sensing, timely control, and rapid display imaging are essential for safe automated driving. Moreover, to meet safety requirements, it’s crucial to monitor the internal operating conditions of the unit and address any functionality loss due to unit failure. To achieve this, there’s an increasing need for more cameras and sensors to monitor external situations, and the infotainment system must be multifunctional to convey and display these situations. With the addition of electronic circuits to monitor each unit’s operating conditions, the complexity of electronic circuits is increasing, leading to more time spent on the design of units and systems.
REFRPT001, the reference design by ROHM semiconductor, presents a power tree solution board tailored for infotainment devices such as automotive clusters, centre information displays, and ECUs for ADAS applications. The design features an eighth-circuit power tree that ensures comprehensive coverage of the necessary power systems. The design incorporates built-in Primary DC/DC Converter ICs from the BD9P series to provide a stable power supply, especially immediately after battery cranking.
In addition to the primary converters, the design includes Secondary DC/DC Converter ICs from the BD9S series. These converters are notable for their industry-leading compact size and high efficiency, which contribute to the overall performance of the power system. The built-in Power Supply Monitoring IC is a key design component with self-diagnostic functions. This IC monitors all eight output rails, playing a crucial role in enhancing the functional safety level of the system.
The reference design underwent rigorous system-level validation, including Standard Electrical Characteristics tests, EMC tests that complied with CISPR25 Class 5 without an input filter, and Thermal performance tests. The thermal tests demonstrated that the separate placement of high-efficiency DC/DC converters effectively distributes heat, ensuring optimal thermal performance.
Moreover, all onboard ICs and discrete parts in the design meet the automotive AEC-Q100 or AEC-Q101 grade compliance, ensuring their reliability and suitability for automotive applications. The main ICs in the design are categorized as functional safety products, supporting the FS category and further underscoring the design’s focus on safety.
The design is engineered to supply power to System-on-Chip (SoC), Microcontroller Unit (MCU), and CAN devices through two primary DC/DC Converter ICs (BD9P series), which are split into four outputs each. Additionally, the design’s capability to monitor the power rails of all eight outputs enhances the level of functional safety for the entire system.
ROHM Semiconductor has tested this reference design, which comes with a bill of materials (BOM), schematics, and other data. The company’s website has additional data about the reference design. To read more about this reference design, click here.
