94% Performance improvement by time-shift control (TSC) technique in cloud computing voltage regulator module (VRM)

The time-shift control (TSC) technique for voltage regulator module (VRM) is proposed to achieve high performance power supply for servers in cloud computing. Four power stages are adopted to provide high current driving capability and low output ripple. Besides, the power request, which includes the number of active phases and voltage identification (VID), is acknowledged by servers for high driving capability during high throughput and high efficiency during standby mode. Furthermore, to equally distribute the current in each phase, the proposed TSC technique improves the current balance performance and solves the stability problem. In the scale-down clouding computing prototype, the efficiency can be kept higher than 90% over a wide load current range of 2 A. Besides, the performance and operating frequency of the servers in stable operation are not limited by the VRM with the TSC.