Automotive dc-dc converters enable high-speed operation at 2.2MHz

In recent years, the continued electrification of vehicle systems has increased. Combined with the limited amount of power available, this trend emphasizes the need for lower power consumption. At the same time, the output voltage from the batteries and generators can vary widely, demanding a versatile power supply solution. Rohm’s  BD9P series of 12 automotive primary dc-dc converters is optimized for ADAS (Advanced Driver Assistance System) sensors, cameras, and radars, along with car infotainment and instrument clusters.

The need for fast response to provide stable operation and higher power conversion efficiency are crucial, which have been difficult to meet with conventional power supply ICs. The new product adopting original advanced power supply technology, Nano Pulse Control, enables high-speed operation at 2.2MHz that will not interfere with the AM radio band (1.84MHz max.) while achieving high step-down ratio. It is an optimum technology for automotive applications.

The BD9P series ensures stable operation during battery input voltage fluctuation, reducing output overshoot to less than 1/10th of that of conventional products. This eliminates the need for additional output capacitors typically required as countermeasure against overshoot. Additionally, adopting a new control method makes it possible to achieve both high efficiency and fast response (which typically represent a tradeoff). Not only does this provide a 92% power conversion efficiency at heavy loads (at 1A output current), but 85% efficiency at light loads (1mA) as well, ensuring leading-class efficiency across the entire load range. As a result, low power consumption is enabled both when driving and when the engine is stopped (standby current can be reduced).

Combining the new product with the BD9S series of secondary DC/DC converters connected to the subsequent stage leads engineers to faster design of more efficient automotive power supply circuits. Reference designs are also available on ROHM official website. Utilizing reference boards, tools, and ROHM’s free web simulation tool, ROHM Solution Simulator, it is possible to perform simulations close to actual conditions, significantly reducing application design resources.

The new DC/DC converters leverage original Nano Pulse Control technology to achieve an unprecedented step-down ratio combined with stable operation and high efficiency. Qualification under the AEC-Q100 automotive standard has also been acquired, guaranteeing high reliability even under harsh vehicle environments.

ult to provide both high efficiency and fast response at light loads. The BD9P series utilizes a new control method to deliver sufficiently faster response at lower drive currents than that of standard products. This translates to 92% conversion efficiency at heavy loads (at 1A output current) and 85% efficiency at light loads (1mA). Providing leading-class efficiency at both light and heavy loads reduces power consumption while driving, as well as when the engine is stopped.

The available reference designs (which include the BD9P series) have undergone thermal and EMC testing, along with measurement of standard electrical characteristics, and cover power supply systems required for ADAS and infotainment functions. In addition to evaluation reports, various tools such as design data, onboard simulation models, and PCB CAD symbols are offered, facilitating evaluation when used with the REFRPT001-EVK-001 reference board.