Design of Common Electronic Control Unit for Meeting Both 12 Volt and 24 Volt Vehicle Battery Requirements

As electronics is increasingly penetrating automotive subsystems for both passenger and commercial vehicle, need for providing control solutions meeting stringent automotive requirements on one hand and delivering first time right solution based on frugal implementation on another hand is increasingly being felt. Reuse of proven building blocks is one of the key design techniques automotive engineers have been adopting over the years, and automotive embedded systems are no exception. To meet such expectations, vehicle OEMs desire a common Electronic Control Unit (ECU) architecture wherever possible.

However as on date, most of the tier-1 suppliers provide different ECU architectures for both 12 Volt and 24 Volt applications. Key challenges are use of common interfaces for output and input devices as well as a common power-supply design which meets 8 to 36 volt requirements. This paper describes the hurdles and solutions for meeting this requirement. It dwells upon challenges encountered in power-supply architecture meeting 8 to 36 volt range, apart meeting the requirements of output devices like lamp loads which may cause nuisance tripping due to cold in-rush current if a common driver chip is used to drive both 12 volt and 24 volt lamps. The paper is based on real life experiences and sums-up the lessons learnt which could be used as the best practices for ECUs catering to both passenger and commercial vehicles.