QuiCur technology greatly increases design flexibility of increasingly sophisticated power supply circuits in automotive applications. ROHM has developed the BD9S402MUF-C DC/DC buck converter IC with integrated MOSFET (switching regulator), designed for increasingly advanced automotive applications such as infotainment systems and ADAS (Advanced Driver Assistance Systems) equipped with cameras and on-board sensors.
In recent years, safety requirements in the automotive sector have become increasingly stringent, in step with the continuous advancement of technological innovation in accident prevention and autonomous driving systems. In the wake of this trend, the SoCs and microcontrollers that control ADAS equipped with on-board cameras and sensors involve greater sophistication and therefore require power ICs capable of operating more stably even during significant fluctuations in load current.
To meet these requirements, in 2017 ROHM created Nano Pulse Control™, an ultra-fast pulse width control technology that provides low output voltage at high switching frequencies, and then introduced QuiCur™, a high-speed load response technology in 2021 that ensures stable operation. Thanks to QuiCur™ technology, the IC boasts a stability of operation that puts it at the top of its class compared to secondary DC/DC converter ICs with equivalent performance for automotive applications. The new ROHM’s BD9S402MUF-C supports low output voltages as low as 0.6 V and an output current of 4 A at switching frequencies above 2 MHz in a compact form factor that lends itself well to increasingly sophisticated secondary power supply applications for high-performance microcontrollers and SoCs. But that’s not all: it features QuiCur™, the proprietary high-speed load response technology that enables stable 30 mV operation, an industry record (measurement conditions: 5 V input voltage, 1.2 V output voltage, 44 µF output electrical capacitance, 0 to 2 A/2 µs load current variation). In other words, with a 25% reduction in output voltage fluctuation compared to class-leading standard products with equivalent functionality, it is the ideal solution for use in the most advanced ADAS systems under severe power supply conditions that require stable operation within 5% even at low output voltage.
The BD9S402MUF-C also features a new load response performance selection function that allows users to easily switch the priority between ‘voltage fluctuation’ (for industry-leading operation stability) and ‘electrical capacitance reduction’ (for 22 µF operation stability) by adjusting the settings via the terminal. Users can thus significantly reduce the resources required for power circuit design due to the stable operation that can be easily achieved not only in the initial design phase, but also in the case of model or specification changes. ROHM plans to expand the line-up of power ICs equipped with QuiCur™ technology in the future to support a wider range of applications.
The BD9S402MUF-C, in addition to meeting the basic requirements of secondary DC/DC converter ICs in ADAS for operation at speeds of 2 MHz or higher and output current of 4 A, features Nano Pulse Control™, ROHM’s unique ultra-fast pulse width control technology that provides a next-generation output voltage as low as 0.6 V, which is much lower than the 1.0 V typically required by today’s SoCs and microcontrollers. It also integrates QuiCur™, the high-speed load response technology that ensures extremely stable operation. The ability to contain output voltage variations to within 5% even at low voltages below 1.0 V makes it an ideal tool for the secondary power supplies of the most advanced ADAS systems. The BD9S402MUF-C also features a load response performance selection function that, by exploiting the features of QuiCur™ technology, allows users to easily switch the priority between ‘voltage fluctuation’ (for industry-leading operating stability) and ‘capacitance reduction’ (to ensure 22 µF operating stability) by acting on the High/Low settings of the GAIN pin. For example, the user can set the GAIN pin to High if the high-performance SoC’s power supply needs to handle rapid load fluctuations, or the user can set the GAIN pin to Low to achieve a good balance between capacitor cost and performance when a microcontroller’s power supply does not need to account for extremely accurate voltage fluctuations. This significantly increases design flexibility for application designers, as stable operation can easily be achieved both during the initial design phase and during model or specification changes.
