Analog circuit and display device using the same
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorHajime Kimura
Life of this patent
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Abstract
The invention provides an analog circuit that decreases an effect of variation of a transistor. By flowing a bias current in a compensation operation, a voltage between the gate and source of the transistor to be compensated is held in a capacitor. In a normal operation, the voltage stored in the compensation operation is added to a signal voltage. As the capacitor holds the voltage according to the characteristics of the transistor to be compensated, the effect of variation can be decreased by adding the voltage stored in the capacitor to the signal voltage. Further, an analog circuit which decreases the effect of variation can be provided by applying the aforementioned basis to a differential circuit, an operational amplifier and the like.
Claims7
An analog circuit comprising a first transistor, a first capacitor, a first switch, a first terminal, a second terminal, a second transistor, a second capacitor, a second switch, a third terminal, and a fourth terminal,
- wherein a gate terminal of the first transistor and one terminal of the first capacitor are electrically connected;
- wherein a gate terminal of the second transistor and one terminal of the second capacitor are electrically connected;
- wherein a source terminal of the first transistor and a source terminal of the second transistor are electrically connected;
- the first terminal and one terminal of the first capacitor are electrically connected via the first switch;
- and
- the third terminal and one terminal of the second capacitor are electrically connected via the second switch, comprising
- a unit for electrically connecting the other terminal of the first capacitor and either of the second terminal or a source terminal of the first transistor;
- and
- a unit for electrically connecting the other terminal of the second capacitor and either of the fourth terminal or a source terminal of the second transistor.
Dependencies are inferred from the claim text.