ROHM (headquartered in Kyoto, Japan), a world-renowned semiconductor manufacturer, has developed 12 models of automotive once-in-a-lifetime sensors, cameras, radars, automotive infotainment systems and dashboards related to ADAS (Advanced Driver Assistance Systems). *1DC/DC converter*2 “BD9P series” product.

In recent years, the Electronic process of automobiles has advanced by leaps and bounds, but due to the limited power that can be provided by the batteries and generators of automobiles, there is an increasing demand for reducing power consumption. In addition, there are large fluctuations in the voltage output from the battery and generator. However, it has been difficult to achieve high-speed response that contributes to stable operation and high power conversion efficiency that contributes to energy saving at the same time for power supply ICs that control the power supply.

ROHM Launches “BD9P Series” Automotive Primary DC/DC Converters Resistant to Battery Voltage Fluctuations

The new product adopts ROHM’s own power supply technology “Nano Pulse ControlTM*”, and adopts a new control method. At the same time, it has the advantages of high-speed response and high-efficiency that were originally contradictory, and has been highly praised by various in-vehicle product manufacturers.

The “BD9P series” can operate stably when the input voltage of the battery fluctuates. Compared with ordinary products, the output overshoot when the voltage fluctuates can be suppressed to less than 1/10, so it is no longer necessary to add the conventional overshoot countermeasures. output capacitor.

In addition, the new product has the advantages of high-speed response and high efficiency, which are usually regarded as contradictory, by adopting a new control method. Not only the power conversion efficiency at high load is as high as 92% (when the output current is 1A), but also the power conversion efficiency at light load is 85% (at 1mA), which achieves an excellent high performance from light load to high load. efficiency, which will go a long way towards further reducing power consumption while driving and when the engine is stopped.

Not only that, but the new product can be combined with the secondary DC/DC converter “BD9S series” connected to its rear stage to form a high-efficiency and high-speed in-vehicle power supply circuit. These solutions have been published on the official website as reference designs provided by ROHM. By utilizing reference boards, various tools, and ROHM’s free online simulation tool “ROHM Solution Simulator”, simulations close to actual use can also be performed, and the design burden of application products can be greatly reduced.

The new product has been put into mass production with a monthly output of 50,000 units in October 2020 (sample price 500 yen/unit, excluding tax).

In the future, ROHM will continue to develop products that help to further reduce power consumption and improve system reliability, and will continue to contribute to the development of the automotive industry.

ROHM Launches “BD9P Series” Automotive Primary DC/DC Converters Resistant to Battery Voltage Fluctuations

ROHM Launches “BD9P Series” Automotive Primary DC/DC Converters Resistant to Battery Voltage Fluctuations

<Details of features>

The new product is a DC/DC converter that achieves a very high step-down ratio by using “Nano Pulse ControlTM” technology, and can operate with high efficiency and stability. The new product also supports the automotive electronics reliability standard AEC-Q100, which ensures high reliability in harsh vehicle environments.

1. No overshoot even when the battery voltage fluctuates and can work stably

When the input voltage is lower than the output setting voltage and returns to the voltage before the fluctuation, the output voltage overshoot problem occurs. This is a problem that has existed for a long time. The new product can suppress this process within 1/10, Therefore, the output capacitors that ordinary products need to add as overshoot countermeasures are no longer required. Therefore, the device can work stably even in the event of sudden battery voltage fluctuations during startup.

ROHM Launches “BD9P Series” Automotive Primary DC/DC Converters Resistant to Battery Voltage Fluctuations

2. Achieve high efficiency over a wider range of load currents, helping to further reduce the power consumption of application products

New products offer both high-speed response and high-efficiency advantages, which are often considered contradictory.

Power ICs using conventional technologies require a large drive current to ensure high-speed response performance, and it is difficult to achieve both high-speed response and high efficiency at light loads. The new product is equipped with a circuit that adopts a new control method, and can fully realize high-speed response with a drive current lower than that of ordinary products. This not only makes the conversion efficiency as high as 92% at high load (at 1A output current), but also makes the conversion efficiency at light load reach 85% (at 1mA). Excellent efficiency is achieved from light load to high load, so it is very helpful to reduce the power consumption of application products whether when the engine is stopped or when driving.

3. Adopt Nano Pulse ControlTM technology to achieve high step-down ratio and stable operation

The new product adopts ROHM’s own ultra-high-speed pulse control technology “Nano Pulse ControlTM”, which always works at 2.2MHz without interfering with the AM broadcast band (1.84MHz Max.), and also realizes high-voltage input of up to 40V from the rear stage. 3.3V ~ 5.0V level stable output driven by components. In addition, the built-in spread spectrum function reduces noise peaks, making it ideal for automotive applications where radiated noise is particularly critical.

4. Provide tools that help reduce supporting product development man-hours

ROHM’s published reference designs and “ROHM Solution Simulator” help to greatly reduce design man-hours at various design stages such as circuit design, circuit board design, noise reduction design, thermal design, and simulation.

ROHM Launches “BD9P Series” Automotive Primary DC/DC Converters Resistant to Battery Voltage Fluctuations

reference design

The reference designs, including the new product “BD9P series”, cover the power supply system required for ADAS/infotainment functions, and have completed not only standard electrical characteristics tests, but also EMC tests, thermal tests and other tests. In addition, evaluation reports and various tools, including design data, simulation models of mounted products, symbols for PCB CAD, etc., are published. Furthermore, by using the reference board “REFRPT001-EVK-001”, it is also possible to easily perform actual machine verification.

Reference design link:

Various tools published

Design data (circuit diagram, BOM, PCB data, etc.)

Simulation model (SPICE model, model for thermal simulation)

PCB library (symbols, pin pads, etc. for CAD tools)

ROHM Solution Simulator

“ROHM Solution Simulator” is an online simulation tool that can simultaneously verify products such as power components (power semiconductors), driver ICs, and power supply ICs on circuit solutions. ROHM provides reference circuit diagrams including new products as part of reference designs, and provides various tools to support customers’ development.

“ROHM Solution Simulator” link:

<Lineup of BD9P series>

The new products include output voltage 3.3V, 5.0V and adjustable series products, which can support a wide range of circuit types.

ADAS sensors, cameras, radar

Automotive infotainment system, instrument cluster, BCM (Body Control Module), etc.

Applications requiring small size, high efficiency, and high reliability in automobiles

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