| 摘要 |
PROBLEM TO BE SOLVED: To provide a ground capacitance estimation circuit capable of estimating the value of a large grounded capacitance.SOLUTION: A ground capacitance estimation circuit (1) comprises: a ground sensing capacity (Cs) that is grounded or equivalently grounded; an integration circuit (10); a charge section (14) for applying an electric charge to the integration circuit (10); and a feedback section (13) for applying, to the integration circuit (10), an electric charge of a polarity reverse to that of the charge section (14). The ground sensing capacity (Cs) is included in the feedback section (13) to which a feedback voltage (Vfb) from a DA converter (12) is applied. |
