Battery fuel gauges using FET segment control to increase low current measurement accuracy
US9797959B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 19, 2013 |
| Grant date | Oct 24, 2017 |
| Priority date | — |
| Expiry date | Sep 10, 2035 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A circuit comprises a battery field-effect transistor (FET) coupled between a battery and an electronic system so that current from the battery flows through the battery FET to the electronic system. A replica FET couples the battery to a current sensing circuit. One of the battery FET and the replica FET comprises a plurality of parallel FET segments having separate control terminals. A logic block provides a plurality of switch control signals based on a system state input. A switching circuit receives the switch control signals and selectively couples the separate control terminals of the FET segments to one of a first reference voltage terminal or a second reference voltage terminal to independently turn each FET segment on or off. The current sensing circuit provides a voltage indicative of the current flowing through the replica FET.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.