| 摘要 |
PROBLEM TO BE SOLVED: To facilitate control of a resistance value in a variable resistance device by reducing variations in forward transfer admittance among individuals and an influence of an ambient temperature. SOLUTION: The variable resistance device including a MOS-FET 10 having a drain-source resistance value controlled by a voltage applied to a gate thereof includes: a reference resistor 20 connected to the drain or the source; a first potential difference detection portion 40 which detects a potential difference between the drain and the source in the case that a current flows between the drain and the source and to the reference resistor 20; a second potential difference detection portion 30 which detects a potential difference between both ends of the reference resistor; a division portion 50 which performs division of a detection result of the first potential difference detection portion and that of the second potential difference detection portion; a target signal generation portion 64 which includes a D/A converter 61 and generates a voltage corresponding to a resistance value to be set in the variable resistance device; and a feedback portion which takes a difference between an output of the division portion 50 and an output of the target signal generation portion 64 as an error signal and feeds back its integral value to the gate of the MOS-FET 10. COPYRIGHT: (C)2011,JPO&INPIT
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