Automotive MCU system power supplies for idling-stop systems

October 31, 2014 // By Graham Prophet
Rohm has developed system power supplies for high-performance microcontrollers in a variety of automotive systems, from electronic power steering to fuel injection, including HEVs and EVs. The BD39001EKV-C uses a proprietary boost-buck switching method that ensures stable voltage supply, even when the battery voltage drops after idling stop, while improving power conversion efficiency by up to 5% vs. conventional products.

A startup sequence setting function is included that can adapt to a variety of MCU specifications and requirements. With the continuing trend towards platform unification (standardisation) in the automotive sector comes a push to promote the use of common parts worldwide. This is expected to increase demand for versatile products that can suit a variety of requirements and support microcontrollers of all types – as well as high-performance devices and solutions optimised for customized dedicated power supplies and specific applications.

In addition, the need to minimize fuel consumption has led to the adoption of systems that stop the engine during idling and other brief stops in order to prevent wasteful fuel consumption. However, this requires countermeasures to prevent MCU malfunction due to battery voltage fluctuations caused by cranking after the engine starts up again.