| abstract |
The operation speed of a circuit is improved. A first transistor has a function of connecting a first terminal to a gate of the first transistor and setting a potential of the gate of the first transistor to a value at which the first transistor is turned on. The second transistor, the third transistor having a function of setting the gate potential of the second transistor to a value at which the second transistor is turned on, and bringing the gate of the second transistor into a floating state, And a fourth transistor having a function of setting the potential of the gate of the transistor to a value at which the second transistor is turned off. With such a structure, the potential difference between the gate and the source of the second transistor can be maintained at a value larger than the threshold voltage of the second transistor, and the operation speed can be improved. [Selection] Figure 1 |