Title:
BATTERY FUEL GAUGES USING FET SEGMENT CONTROL TO INCREASE LOW CURRENT MEASUREMENT ACCURACY
Document Type and Number:
WIPO Patent Application WO/2015/077234
Kind Code:
A3
Abstract:
A circuit comprises a battery field-effect transistor (FET 512) coupled between a battery (502) and an electronic system (518) 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 (520) provides a plurality of switch control signals (544) based on a system state input. A switching circuit (510) 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 (506) provides a voltage indicative of the current flowing through the replica FET.
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Inventors:
MIKUTEIT ERIC IAN (US)
Application Number:
PCT/US2014/066163
Publication Date:
July 16, 2015
Filing Date:
November 18, 2014
Export Citation:
Assignee:
QUALCOMM INC (US)
International Classes:
G01R19/00; G01R15/09; H01M10/48; G01R1/20; G01R31/36
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Attorney, Agent or Firm:
WELLER, Edward B. (900 Lafayette St.Suite 30, Santa Clara California, US)
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