发明名称 |
Method and apparatus for measuring battery charge and discharge current using a direct analog-to-digital conversion of a charge/discharge replica current |
摘要 |
Disclosed is a method for charging a battery and circuitry for performing the method. The method includes steps of: (A) generating at a first node a battery charge current (Icharge) for charging the battery; (B) generating at a second node a replica current (Irep) from Icharge, where Irep<Icharge; and (C) operating a closed loop current sink for sinking Irep, where a digital output of said closed loop current sink is a measure of the magnitude of Icharge. In the preferred embodiment the digital output is input to a control circuit for controlling the generation of Icharge. Also in the preferred embodiment the closed loop current sink is constructed from a multi-stage DAC that is driven by an output of an n-level digital filter that is incremented or decremented as a function of a voltage difference between the first node and the second node. Preferably the multi-stage DAC is a multi-stage current steering DAC, and the n-level digital filter is constructed using an up/down counter. A selection of stages of the multi-stage DAC to be turned off and on is made by a DEM logic block that is interposed between the output of the counter and the multi-stage DAC. The disclosed circuitry and method may be extended for providing a battery discharge measurement circuit for enabling a battery capacity test to be performed.
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申请公布号 |
US6507171(B2) |
申请公布日期 |
2003.01.14 |
申请号 |
US20010029744 |
申请日期 |
2001.12.21 |
申请人 |
NOKIA CORPORATION |
发明人 |
RUHA ANTTI;RUOTSALAINEN TARMO;TERVALUOTO JUSSI-PEKKA;KAUPPINEN JANI |
分类号 |
G01R31/36;H01M10/44;H01M10/46;H01M10/48;H02J7/00;H02J7/04;H02J7/10;H02J7/16;(IPC1-7):H01M10/44 |
主分类号 |
G01R31/36 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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