Improving The Dynamic Performance Of Vrm Based On AVP

An evolution in integrated circuits poses new challenges for its power supply called voltage regulator modules(VRMs). To meet the requirements of fast load transient response, VRMs must improve its dynamic response.Transient characteristic on dynamic load of VRMs is analyzed and specific requirements of VRMs are described in this thesis. The view is shown that it is difficulty and essential to improve dynamic response of VRMs.Several different control methods are described in brief, which focus on optimizing dynamic response of VRMs. The results obtained by investigating the features of these control methods show that adaptive voltage position (AVP ) design gives an effective elevation feeding transient requirements of VRMs.The small signal models for VRMs using various control methods are derived, which are employed to explore the relationship between dynamic characteristic of VRMs and circuit parameters. This thesis introduces the concept of critical bandwidth and critical inductance, which are good design tradeoff between the efficiency and transient response for VRMs.Adaptive voltage position design is discussed particularly which can enhance dynamic characteristic of VRMs. Both the current-mode and V2 control technique are analyzed in detail, which are utilized to achieve constant output impedance, to approach perfect AVP for the VRMs transient response. Simulation results prove the theoretical analysis.