| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a coulomb counter which can integrate the amount (coulomb amount) of charge/discharge of a secondary battery inside the coulomb counter, can read out the integrated coulomb amount at arbitrary timing, can reduce a circuit scale, and is expected to reduce a cost. <P>SOLUTION: The coulomb counter 100a which converts a potential difference generated between both ends of a detection resistor into be an input voltage and outputs a count value proportional to the input voltage includes: a delta-sigma modulator 100 which converts the input voltage into an input signal and outputs a pulse signal having a duty ratio according to the input voltage; and an up-down counter 101 which counts values up when the output pulse of the delta-sigma modulator is at high level when a clock signal is input, and counts the values down when the output pulse of the delta-sigma modulator is at low level when the clock signal is input. <P>COPYRIGHT: (C)2012,JPO&INPIT |
