| 摘要 |
PROBLEM TO BE SOLVED: To prevent a reduction in accuracy of adjusting impedance.SOLUTION: The impedance adjustment circuit includes: first and second external terminals to be connected to external resistors; a first dummy buffer part having output impedance adjusted in accordance with a first switch connected between the first external terminal and a first power line, and a first control signal; a second dummy buffer part having output impedance adjusted in accordance with a second switch connected between the second external terminal and a second power line, and a second control signal; and a control part for setting the output impedance of the first dummy buffer part by the first control signal in accordance with the voltage of the first external terminal by closing the first switch and opening the second switch, and setting the output impedance of the second dummy buffer part by the second control signal in accordance with the voltage of the second externa terminal by opening the first switch and closing the second switch. |
