Modeling and Design for a Novel Adaptive Voltage Positioning (AVP) Scheme for Multiphase VRMs

Author

Lee, Martin ; Chen, Dan ; Huang, Kevin ; Liu, Chih-Wen ; Tai, Ben

Author_Institution

Dept. of Electr. Eng., Nat. Taiwan Univ., Taipei

Volume

23

Issue

4

fYear

2008

fDate

7/1/2008 12:00:00 AM

Firstpage

1733

Lastpage

1742

Abstract

Adaptive voltage positioning (AVP) has been used in multiphase voltage regulator module (VRM) applications. A novel scheme, called AVP+, is analyzed in this paper. Small signal model is used to look into the control performance issues such as output impedance and stability. The model has been verified in the experiments and simulations. Compared to a conventional AVP schemes, the present scheme provides better stability margin and output- impedance performance. This is especially true for the prevailing trend of using ceramic output capacitors and high switching frequency. The focus of the present paper is the small-signal modeling for control loop design using the AVP+ scheme which was never analyzed before. And the comparisons were made between AVP+ and AVP- on the stability and output impedance performance.

Keywords

circuit stability; electric impedance; voltage control; voltage regulators; AVP+ scheme; adaptive voltage positioning scheme; control loop design; multiphase VRM; multiphase synchronous buck converter; multiphase voltage regulator module; output impedance; small signal model; stability margin; Buck converters; Capacitors; Ceramics; Circuits; Impedance; Output feedback; Regulators; Stability; Switching frequency; Voltage; Adaptive voltage positioning (AVP)+ control; constant output impedance; stability; voltage regulator;

fLanguage

English

Journal_Title

Power Electronics, IEEE Transactions on

Publisher

ieee

ISSN

0885-8993

Type

jour

DOI

10.1109/TPEL.2008.924822

Filename

4558239