Patent ID: 7714616

Claim:
A semiconductor device comprising: a first p-channel type transistor; an n-channel type transistor; a second p-channel type transistor; and a diode connected transistor, wherein a gate of the first p-channel type transistor is electrically connected to a gate of the n-channel type transistor, one of a source and a drain of the first p-channel type transistor is electrically connected to a first wiring, the other of the source and the drain of the first p-channel type transistor is electrically connected to one of a source and a drain of the n-channel type transistor, the other of the source and the drain of the n-channel type transistor is electrically connected to a second wiring, the other of the source and the drain of the first p-channel type transistor is electrically connected to a gate of the second p-channel type transistor, one of a source and a drain of the second p-channel type transistor is electrically connected to a third wiring, and the other of the source and the drain of the second p-channel type transistor is electrically connected to a fourth wiring and the diode connected transistor, and wherein a ratio of a gate width to a gate length of the n-channel type transistor is five times or more as much as a ratio of a gate width to a gate length of the first p-channel type transistor.