Abstract: In an operational amplifier, a differential amplifying circuit is configured to amplify an input voltage inputted from the input terminal. An outputting transistor is connected to the output terminal. A driving transistor is connected to the differential amplifying circuit and the outputting transistor. The driving transistor turns on according to a control signal supplied from the differential amplifying circuit to the driving circuit. The driving transistor is also configured to drive the outputting transistor according to the control signal. A control signal reducing circuit, when a voltage is applied on the driving transistor through the outputting transistor, is configured to reduce the control signal within a range that the driving transistor is kept to on state. The voltage applied on the driving transistor exceeds a predetermined threshold voltage.

Abstract: First slits are alternately cut from opposing sides of a resistance element by a serpentine-cut laser trimming. Each slit is perpendicular to the longitudinal axis of the resistance element. The slits are cut for roughly adjusting a resistance of the resistance element. Second slits are cut between and in parallel to the first slits. The slits are cut for fine adjusting the resistance of the resistance element. A range of the fine-adjustment for a variation in the resistance is estimated by changing a distance between the first slits and the second slits.