Current sensing in multiple coupled inductors by time constant matching to leakage inductance
US7233132B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 30, 2006 |
| Grant date | Jun 19, 2007 |
| Priority date | — |
| Expiry date | Jan 30, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M1/0009
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
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 voltages 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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.