Abstract: A switched-capacitor circuit performing two-phase operation with a sampling phase and an amplification phase comprising: an inverter having a common source type input transistor and a load transistor; a first capacitor whose first terminal is connected to a gate of the input transistor serving as an input of the inverter; a first switch which connects between the input (the gate of the input transistor) and the output of the inverter, which turns on during the sampling phase and turns off during the amplification phase; a second switch which connects a second terminal of the first capacitor to an input voltage terminal during the sampling phase, and connects the second terminal of the first capacitor to the output terminal of the inverter during the amplification phase; a second capacitor whose first terminal is connected to a gate of the load transistor of the inverter and whose second terminal is connected to the second terminal of the first capacitor; and a third switch which connects the first terminal of

Abstract: D/A converter of this invention including n+1 capacitors in total consisting of one terminating capacitor (C0) and n binary-weighted capacitors (C1-4) that are subjected to binary weighting ratio of 1:2:4: . . . :2(n?1), and, an inverting amplifier (INV1), further comprising: a feedback switching means (SWR5) provided between the input and output of the inverting amplifier (INV1); a switching means for terminating operation (SWR0) supplies one of two main reference voltages (VB,VT) to the terminating capacitor (C0), and then, makes connection of the terminating capacitor (C0) to the output of the inverting amplifier (INV1); a plurality of switching means for input operation (SWD1-4,SWR1-4) makes selection of one of the two main reference voltages (VB,VT) to be provided for the n binary-weighted capacitors (C1-4) depending on digital data (D1-4), and then, makes connection of the second terminal side of the n binary-weighted capacitors (C1-4) to the output of the inverting amplifier (INV1).

Abstract: The present invention relates to a weighted mean calculation circuit that comprises an inverting amplifier; a plurality of capacitors C1 through Cn connected to the input terminal thereof; switches SW1 through SWn that connect the capacitors C1 through Cn to the input and output terminals of the inverting amplifier; and a switch SW0 that is provided between the input and output of the inverting amplifier. A signal voltage is applied to respective capacitors while making the SW0 conductive when inputting a signal, and the capacitors C1 through Cn are connected in parallel between the input and output of the inverting amplifier while making the SW0 non-conductive when outputting a signal, whereby an output signal Vout is read, and a weighted mean value output that does not include any offset and is normalized as a normal polarity output can be obtained.