| 摘要 |
PROBLEM TO BE SOLVED: To provide an analogue operating circuit where an MOS transistor (or MIS transistor) is used for precise multiplication and/or division with an input voltage, at a lower operation voltage and a low cost for high reproducibility. SOLUTION: Two VGAs (variable gain amplifier) 11 and 12 are configured identically or similarly using an MIS (metal-insulator-semiconductor) transistor. The VGA11 is provided with a negative feedback loop in which an amplified output voltage Vox of a prescribed input voltage Vx tracks a first input voltage V1. The other VGA12 is made to amplify a second input voltage V2 under the gain setting condition of the VGA11 which is formed by the negative feedback loop, for multiplying the second input voltage with the first input voltage. COPYRIGHT: (C)2005,JPO&NCIPI |
