Efficiency Measurement Method for Fully Integrated Voltage Regulators used in 4^th and 5^th Generation Intel® Core™ Microprocessors

Fully Integrated Voltage Regulators (FIVRs) are switching voltage regulators integrated on to the same die as the CPU and Graphics cores, in 4 ^th and 5 ^th generation Intel ^® Core™ microprocessors. Practical limitations prevent the application of traditional voltage regulator characterization methods to FIVRs. To overcome these challenges, new methods and techniques had to be developed for the testing and characterization of FIVRs. Power Efficiency (η) is one of the key performance metrics of voltage regulators. In this paper we explain the methods used to measure the Power Efficiency of FIVRs. These methods are applicable to Integrated VRs in general and are not specific to FIVRs alone. Description of power loss components and extraction of the loss coefficients from curve fitting technique is also presented. Measured results show that the proposed methods are highly repeatable with worst-case run-to-run variation of 0.4%. The results also show that the worst-case error is <; 1% when compared to pre-Si simulation results.