ROHM recently released the BD9S402MUF-C, a buck DC/DC converter IC with built-in MOSFET (Switching regulator), BD9S402MUF-C, for automotive applications such as infotainment and ADAS (Advanced Driver Assistance Systems) incorporating onboard sensors and cameras that are becoming more advanced.

In recent years, safety requirements in the automotive sector have increased as technological innovations in accident prevention and autonomous driving continue to progress. In line with this, SoCs and MCUs that control ADAS incorporating onboard sensors and cameras are leading to greater sophistication, necessitating power supply ICs to operate more stably even under severe load current fluctuation conditions.

To meet these needs, in 2017, ROHM established Nano Pulse Control™ ultra-high-speed pulse control technology that provides low output voltage at high switching frequencies, followed by QuiCur™ high-speed load response technology in 2021 that ensures stable operation. The IC to adopt QuiCur™ technology allows for class-leading stable operation compared with automotive secondary DC/DC converter ICs with equivalent performance.

The new BD9S402MUF-C supports output voltages down to 0.6V and 4A output current at switching frequencies higher than 2MHz in a compact size demanded by increasingly sophisticated secondary power supply applications for high performance MCUs and SoCs. What’s more, it is incorporating proprietary QuiCur™ high-speed load response technology and enables stable operation at an industry-leading 30mV (measurement conditions: 5V input voltage, 1.2V output voltage, 44μF output capacitance, load current variation 0 to 2A/2μs). This translates to a 25% reduction in output voltage fluctuation over class-leading standard products with equivalent functionality, making it ideal for use in the latest ADAS with severe power supply conditions requiring stable operation within 5% even with low voltage output.


The BD9S402MUF-C is also equipped with a new load response performance selection function that allows users to easily switch priority between ‘voltage fluctuation’ (for industry-leading stable operation), and ‘capacitance reduction’ (to ensure stable operation at 22μF) via terminal setting. The result is that users can significantly reduce the resources required for power circuit design, as stable operation can be easily achieved not only at the initial design, but also during specification or model changes.

Samples are available now, with mass production expected in April 2023. For more information, please click BD9S402MUF-C.