| 摘要 |
PURPOSE: An on-die termination circuit is provided to accurately control impedance through passive resistors of low number by selectively assembling a plurality of passive resistors. CONSTITUTION: An on-die termination circuit includes a passive resistor part(260), a plurality of first MOS transistors(220A~220C), and a plurality of second MOS transistors(240A~240C). The passive resistor part includes a plurality of passive resistors which is serially connected. A plurality of first MOS transistors delivers a power voltage to the passive resistor part in response to a first control signal. A plurality of second MOS transistors delivers a ground voltage to the passive resistor part in response to a second control signal. Impedance is controlled according to a first resistor value due to a turn-on state of the first MOS transistors and the second MOS transistors and a second resistor value of the passive resistor for sending a current inside the passive resistor part. |
