Semiconductor device having pull-up circuit and pull-down circuit

摘要

To reduce power supply noises occurring in a control circuit unit for controlling an output buffer. A semiconductor device includes unit buffers for driving a data output terminal, impedance control circuits for controlling the unit buffers, and a control circuit unit for controlling the impedance control circuits. The impedance control circuits and the control circuit unit operate by mutually-different power supplies, the control circuit unit supplies pull-up data and pull-down data in mutually reverse phase to the impedance control circuits, and the impedance control circuits convert the pull-up data and the pull-down data from reverse phase to in-phase and supply the same to the unit buffers. Thereby, a noise is difficult to occur in a power supply VDD used for the control circuit unit.

主权项

1. A semiconductor device comprising:
a data output terminal; first and second power supply lines each supplied with a first power supply potential, the first and second power supply lines being separated from each other; third and fourth power supply lines each supplied with a second power supply potential, the third and fourth power supply lines being separated from each other; a first driver coupled between the data output terminal and the first power supply line; a second driver coupled between the data output terminal and the third power supply line; a first control circuit unit coupled between the first and the third power supply lines, the first control circuit unit supplying the first driver with a first signal and supplying the second driver with a second signal that is in phase to the first signal; and a second control circuit unit coupled between the second and the fourth power supply lines, the second control circuit unit supplying the first control circuit unit with a third signal that is in phase to the first signal and a fourth signal that is complementary to the first signal, the first control circuit unit receiving the third and the fourth signals, outputting the first signal in response to the third signal, and outputting the second signal in response to the fourth signal, wherein the first and second power supply lines are connected to different power supply terminals from each other, the third and fourth power supply lines are connected to different power supply terminals from each other, the first power supply line is lower in impedance than the second power supply line, and the third power supply line is lower in impedance than the fourth power supply line.