Input voltage influence on voltage regulator modules based on multiphase buck and multiphase half bridge topologies

Increasing the input voltage of voltage regulator modules provides very attractive advantages to the system, reducing the distribution losses and improving the system stability. This paper analyzes how the increment of the input voltage affects the VRM itself. Several multiphase buck and multiphase half bridge solutions are designed, tested and compared to determine the influence of the input voltage on the efficiency, cost and size of the VRMs. Despite the results that might be expected, the multiphase half bridge (without isolation) solutions with 24 V input voltage are very competitive in terms of cost, size and efficiency compared with 12 V multiphase buck converters.