Comparative Study of 48V-based Low-Power Automotive Architectures

This paper describes a comparative analysis of low-power 48V-based automotive power distribution subnets in terms of efficiency, total footprint area, and cost. A novel methodology for the enumeration of tree-based power architectures is first disclosed which strongly limits the number of valid candidates. Next, architectural solutions based on the use of Buck converters only are compared with variants employing dedicated topologies for high step-down (HSD) conversion (e.g. 48V-1V), as well as fixed conversion ratio stages based on switched-capacitor (SC) converters. Use of efficient HSD and SC stages leads to more efficient architectures, although in general still not cost-competitive with traditional ones due to the absence of highly integrated commercial solutions. The discussion is developed around a specific case study treated numerically on the basis of data extracted from commercially-available examples.