Patent ID: 8013348
Filing Date: 2011-09-06
Classification: H05B

Abstract:
1. A semiconductor device, comprising: a plurality of light emitting diodes; a plurality of transistors having substantially uniform size and having sources and drains, the drains of the plurality of transistors being connected to respective ones of the plurality of light emitting diodes to drive said respective ones of the plurality of light emitting diodes; a source pad connected to the sources of each of the plurality of transistors and configured to supply an electric current to the sources of each of the plurality of transistors; a plurality of wires configured to connect the source pad and the sources of each of the plurality of transistors and to provide substantially equal resistance to the electric current passing from the source pad to the sources of each of the plurality of transistors; and a transistor of a reduced size relative to said plurality of transistors of substantially uniform size, the reduced size transistor having a gate and a drain connected together, the reduced size transistor providing a gate-source voltage generated by providing a constant current to the drain of the reduced size transistor as a bias voltage to gates of the plurality of transistors, wherein the gate of the reduced size transistor is connected to the gates of said plurality of transistors of substantially uniform size, wherein at least one of the plurality of transistors is closer to the source pad relative to another one of the plurality of transistors and a wire connecting said at least one closer transistor to the source pad is at least as long as a wire connecting said another one of the plurality of transistors to the source pad.