Patent ID: 7746157

Claim:
A semiconductor device comprising: a first transistor; a second transistor; a third transistor; a fourth transistor; a fifth transistor; and a capacitor, wherein: one of a source and a drain of the first transistor is electrically connected to a first wiring, wherein the first wiring is kept at a first potential, the other of the source and the drain of the first transistor is electrically connected to one of a source and a drain of the fourth transistor, a gate of the first transistor is electrically connected to one of a source and a drain of the second transistor, the other of the source and the drain of the second transistor is electrically connected to the first wiring, one of a source and a drain of the third transistor is electrically connected to the other of the source and the drain of the fourth transistor, one of a source and a drain of the fifth transistor is electrically connected to a second wiring, wherein the second wiring is kept at a second potential, a first electrode of the capacitor is electrically connected to the gate of the first transistor, and a second electrode of the capacitor is electrically connected to the other of the source and the drain of the fourth transistor.