| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a source follower circuit which has low power consumption and high output voltage accuracy, and to provide a display device having the source follower circuit as an output buffer. <P>SOLUTION: The source follower circuit 100 includes a transistor T1 provided as a source follower transistor, a transistor T2 cascode-connected to the source follower transistor, a current source 120, an offset compensating circuit 130, and a voltage setting circuit 140. The offset compensating circuit 130 has a capacitor C1 for storing a threshold voltage of the transistor T1 as an offset voltage, and the gate voltage of the transistor T1 is set so as to cancel an influence affecting the output voltage VO by the offset voltage. The voltage setting circuit 140 sets the gate voltage of the transistor T2 independent from the gate voltage of the transistor T1. Since capacity coupling does not exist between the gate of the transistor T1 and the gate of the transistor T2, the offset voltage is canceled accurately, and the output voltage VO can be generated accurately in response to an input voltage VI. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
