ROHM announced the availability of a buck-boost power supply chipset that provides the lowest current consumption in the industry along with stable performance (transient response characteristics) in automotive ECUs (Electronic Control Units) for cluster panels and gateways used in start-stop vehicle systems.
The chipset integrates a buck DC/DC converter with boost functionality (BD8P250MUF-C) and a dedicated boost IC (BD90302NUF-C). The primary chip (BD8P250MUF-C) utilises ROHM’s novel buck-boost control technology, dubbed Quick Buck Booster, that enables configuration of a buck-boost power supply without degrading buck power supply characteristics by simply adding the dedicated BD90302NUF-C boost IC to the subsequent stage.
The result is an industry-best no-load current consumption of 8uA and ±100mV output voltage fluctuation utilising an output capacitance 44uF, contributing to improved stability and energy savings in applications where significant input voltage drops occur in a short period of time, such as start-stop vehicle systems.
In addition, Quick Buck Booster technology allows a common board design that integrates both buck-boost and buck power supply topologies along with the requisite peripheral components and noise countermeasures, reducing development time and labor by 50% compared to conventional methods requiring separate buck-boost and buck power supply boards.
In recent years, to meet the greater environmental performance demanded in the automotive sector, the number of vehicles equipped with start-stop functionality that turns the engine/motor OFF while idle has grown significantly. In these systems, a buck-boost power supply is required to prevent malfunctions due to low battery voltage during idling and battery fluctuations (cranking) immediately after start-stop operation, but conventional products are problematic from the standpoint of current consumption and responsiveness, increasing the demand for an improved solution as the number of stop-start vehicles continues to rise.
To meet market demands, the BD8P250MUF-C integrates a spread spectrum function as a countermeasure against noise (EMI), allowing it to clear the international standard (CISPR 25) for noise in the automotive sector. At the same time, ROHM’s original ultra-high-speed pulse control technology Nano Pulse Control is utilised to enable high speed operation at 2.2MHz that eliminates the effects on the AM radio band (1.84MHz max.), making it possible to achieve stable 5V output for ECU drive from high-voltage 36V input. This ensures low electromagnetic interference while enabling low voltage output from high voltage input without AM radio band interference, contributing to stable operation in automotive systems sensitive to noise.
In response, ROHM leveraged analog design technology and power system processes to develop groundbreaking solutions for the automotive market, such as products that integrate Nano Pulse Control high speed pulse control technology. This time, ROHM developed a buck-boost power supply chipset utilising proprietary automotive technology centred on Quick Buck Booster control that overcomes the issues related to start-stop systems. And going forward, ROHM will continue to support the evolution of vehicles by developing products and technologies that contribute to greater power savings and system optimisation.
Buck-Boost Power Supply chipset will be available for use to automotive OEMs from January 2019.