A semiconductor integrated circuit includes a first register, a second register, a gray scale voltage generator which outputs a plurality of gray scale voltages, a decoder which selects a gray scale voltage, and an amplifier including a first transistor, a second transistor, a third transistor, and a fourth transistor. A first terminal of the first transistor and a first terminal of the second transistors are connected to a first voltage line, a first terminal of the third transistor and a first terminal of the fourth transistor are connected to a second voltage line, a second terminal of the first transistor is connected to a second terminal of the third transistor, and a second terminal of the second transistor is connected to a second terminal of the fourth transistor.