Patent ID: 7554362

Claim:
A semiconductor device comprising: a first transistor, wherein one of a source and a drain of the first transistor is electrically connected to a load; a second transistor, wherein a gate of the second transistor is electrically connected to a gate of the first transistor and a source of the second transistor is electrically connected to the source of the first transistor; a first current source for setting a voltage between the gate and the source of the second transistor by supplying a first current to the second transistor; a second current source for setting a voltage between the gate and the source of the first transistor by supplying a second current to the first transistor, wherein the second current source is electrically connected to the other of the source and drain of the first transistor; and a wiring electrically connected to the other of the source and the drain of the first transistor through a switch so that a current which is controlled by a voltage between the gate and the source of the first transistor is supplied to the load.