Module Power Saving Design Based On Multi-phase DC Switch Technique

Most of state-of-the-art processors utilize high efficient multi-phase DC switch modules (voltage-regulator-modules, VRM) as supply units. In consideration of the direct relationship between the performance of CPU and its power consumption, the lower efficiency of VRM circuit leads to larger power energy wasting. Many solutions proposed to improve efficiency of the circuit have gone on the blink except that selecting the appropriate devices and frequency based on the known condition. Therefore, many IC companies have proposed new techniques such as skip mode, burst mode, and so on in the events of light loading. In the case of heavy loading, there have been no effective solutions so far. To resolve the problem, the technique which changes phases between different loadings to improve efficiency emerges as the time requires.This thesis introduces the main circuit components based on the research and analysis of VRM framework. Compared to conventional CPU power module, this thesis uses a new technique that switches between different phases depending on different loadings to obtain high efficiency of dynamic loading. The proposed circuit has proved its superiority and improved the overall energy savings compared with conventional stationary phases circuits based on the test results of the circuit board. In fact, this thesis proposes a 4-phase to 8-phase switching VRM power supply module. The optimal switching point is selected through analyzing and setting the optimal switching phases as well as the simulation results of different phases'efficiency changing with dynamic loadings. Verifying the rationality of the optimal switching point based on the test results is used for consummating the circuit design and achieving the largest energy saving ability. The measured results indicate that light loading results in fewer phases and higher efficiency while heavy load leads to more phases and higher efficiency. When the loading is 10 Amps, the efficiency of 4-phase circuit is improved by 8% compared to 8-phase circuit. On the other hand, 8-phase circuit obtains 4% efficiency higher than 4-phase of 100 amps loading. This project's energy saving effect is relatively satisfactory.