Seiko Epson Corporation

Shinya Ukai

Akira Morita

A control circuit couples a test capacitance element Cp and a node Test to a capacitance element Cm-to be tested, and applies a voltage output from an operational amplifier circuit to the capacitance elements Cm-and Cp and the node Test. Thereafter, the capacitance element Cp and the node Test are decoupled from the capacitance element Cm-to be tested, the capacitance element and the node Test are coupled to the capacitance element Cm-, the charge accumulated in the capacitance element Cm-is moved, a voltage Vref of a negative input-end (−) of a comparison circuit is set, and the capacitance element Cm-is tested based on a signal output from the comparison circuit.

Growing community of inventors

Fujimi-Machi, Japan

Shinya Ukai