New automotive primary DC-DC converters ensuring stable operation

ROHM has designed a new line up of 12 automotive primary DC-DC converters. The BD9P series is optimised for ADAS sensors, cameras, and radars, as well as car infotainment and instrument clusters.

The new product adopts original advanced power supply technology, Nano Pulse Control, enabling high-speed operation at 2.2MHz that will not interfere with the AM radio band (1.84MHz max) while attaining a high step-down ratio. It is an ideal technology for automotive applications.

The series provides stable operation throughout battery input voltage fluctuation, decreasing output overshoot to less than 1/10th compared to conventional products. This eradicates the necessity for further output capacitors commonly needed to decrease overshoot voltages. Also, adopting a new control method makes it feasible to attain both high efficiency and fast load response (which are in a trade-off relationship). The converters provide a 92% power conversion efficiency at heavy loads (at 1A output current), but also 85% efficiency at light loads (1mA), and, therefore, attain class-leading efficiency over the whole load range. This lowers power consumption, which leads to a decrease in CO2 emissions, and the parasitic discharge of the battery is also lessened.

Also, incorporating the new product with the BD9S series of secondary DC-DC converters cascaded to the subsequent stage enables users to configure faster, more efficient automotive power supply circuits. Reference designs are also offered on the company's official website. Using reference boards, tools, and the company's free web simulation tool, 'ROHM Solution Simulator', it is feasible to perform simulations close to actual conditions, significantly decreasing application design resources.