Patent ID: 7859490
Filing Date: 2010-12-28
Classification: G09G

Abstract:
1. A current drive device comprising: a current source transistor for allowing a preset drive current to flow to a drain; a cascode transistor cascode-connected to the current source transistor; a switch circuit for switching ON/OFF flow of the drive current through a drain of the cascode transistor and a circuit to be driven; and a bypass circuit for allowing the drive current to flow therethrough to bypass the switch circuit and the circuit to be driven when the switch circuit is OFF, wherein the bypass circuit comprises a bypass transistor connected to the drain of the cascode transistor at its source and receiving a predetermined fixed gate voltage at its gate, and the predetermined fixed gate voltage is set so that the bypass transistor is ON with respect to a source voltage given when the switch circuit is OFF and OFF with respect to a source voltage given when the switch circuit is ON.