Patent ID: 7358743

Claim:
An accumulated current counter comprising: a sense resistor configured (i) for being coupled in series between an electronic circuit and a power source, and (ii) for use in sensing a voltage across the sense resistor as a function of a current provided via the power source; means coupled to the sense resistor for incrementally counting an amount of current, corresponding to an average value of charge Q, going (i) into or (ii) out of the power source, wherein the incremental counting means comprises an incremental converter; a register for accumulating a representation of the incrementally counted current; a single pole RC filter coupled in parallel with the sense resistor, wherein the single pole RC filter integrates high frequency spikes and provides an anti-aliasing filtering function on the voltage across the sense resistor; a switch (S 1 ) responsive to a control signal for coupling an incremental converter input node between (i) a sense resistor voltage node of the single pole RC filter or (ii) a voltage reference (+/−V REF ) node; and control/postprocessing logic coupled between the incremental converter and the register, the control/postprocessing logic being responsive to the incremental converter for providing data signals to the register, including a positive coulomb increment signal (+1 C) and a negative coulomb increment signal (−1 C), wherein a content of the register is representative of a remaining power source life.