| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To highly accurately perform a calibration operation for adjusting impedance of an output buffer. <P>SOLUTION: A semiconductor device includes: a replica buffer 110 connected to a calibration terminal ZQ; an impedance adjusting circuit 180 that changes the impedance of the replica buffer 110 according to a comparison result between the potential of the terminal ZQ and a reference potential Vref; and an impedance adjusting circuit 190 that changes the impedance of a replica buffer 130 according to a comparison result between the potential of a connection node A of a replica buffer 120 and the replica buffer 130 and the potential of the terminal ZQ. Impedance adjustment is performed for both of the replica buffers 110, 130 on the basis of the potential of the terminal ZQ and accordingly, the adjustment error of one of the replica buffers is not superimposed on the adjustment error of the other replica buffer. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
