Two new U.S. patents on power management technologies awarded to CPES
The CPES Power Management mini-consortium currently includes 14 industry partners. This research is focused on developing pre-competitive technologies in the area of distributed power system architectures in such applications as microprocessors, laptop, desktop, server, and telecom equipment.
Since the establishment of this mini-consortium in 1997, 53 invention disclosures have been generated and 15 U.S. patents awarded, with additional 7 patents pending. In recent months, two new patents on power management technologies have been awarded. These IPs are offered to all CPES Principal Members Plus on a non-exclusive, royalty-free basis with two-year exclusivity.
Overall, since the inception of power electronics research at Virginia Tech in 1977, researchers have produced 185 invention disclosures and been awarded 56 U.S. patents.
Current Sensing in Multiple Coupled Inductors by Time Constant Matching to Leakage Inductance (VTIP #05.064)
- by Yan Dong, Ming Xu, Fred C. Lee
- U.S. Patent #7,233,132 (issued June 19, 2007)
Abstract: Voltage regulators often have coupled output inductors because coupled output inductors provide improvements in cost and efficiency. Coupled inductors are often used in multi-phase voltage regulators. Feedback control of voltage regulators often requires accurate and responsive sensing of output current. Provided is a technique for accurately sensing the magnitude of output current in coupled inductors. An RC circuit (comprising a resistor and capacitor in series) is connected in parallel with the coupled inductor. The inductor has a leakage inductance Lk and a DC (ohmic) resistance of DCR. The resistor and capacitor are selected such that an RC time constant is equal to an L/R time constant of Lk/DCR. With the matching time constants, a sum of voltage on the capacitors is accurately proportional to a sum of currents flowing in the output inductors. Also provided is a technique for sensing current when an uncoupled center tap inductor is present.
Coupled-Inductor Technique for Multi-phase VRs (VTIP #05.040)
- by Jinghai Zhou, Fred C. Lee, Ming Xu, Yan Dong
- U.S. Patent #7,199,695 (issued April 3, 2007)
Abstract: A multiple phase buck converter or boost converter, or buck-boost converter has an inductor in each phase. A magnetic core with a unique woven topology provides inverse coupling between the inductors. The inductors can comprise straight conductors since the magnetic core has the woven topology wrapped around each inductor. The inductors have a reduced electrical resistance since they are straight and do not loop around the magnetic core. The reduced electrical resistance increases energy efficiency and improves transient response of the circuit. The magnetic core can comprise top and bottom portions that are magnetically connected. The inductors can comprise straight circuit board traces and the circuit board can have holes to accommodate the magnetic core.
For more information about CPES Intellectual Property, please contact Teresa Shaw.