Current sensing structure for integrated power switches
US7202694B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 19, 2005 |
| Grant date | Apr 10, 2007 |
| Priority date | — |
| Expiry date | Oct 16, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M1/0009
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Circuits and methods to sense the current through a coil of an integrated switching converter, applicable to boost and to buck converters, have been achieved. The present invention uses a “replica biasing” technique to avoid a resistor for current measurement. The current through a pass device is mirrored into a replica, having a scale of n and being much smaller in size, of said pass device. The current through the replica is mirrored to another branch of the circuit and back again to achieve a fast stabilization of the current. The current through the replica is mirrored again to an output branch of the circuit, which conducts exactly a fraction 1/n of the current flowing through the pass device. The self-biasing current loop of the invention adapts quickly to the actual current level through the pass device of the switching converter. Accuracies better than 5% are achieved over a wide range of dynamic range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.