| 摘要 |
PURPOSE: An output buffer of a semiconductor device is provided to perform a high speed operation and to suppress a noise by reducing a peak current. CONSTITUTION: An output buffer of a semiconductor device includes a first pull-up and pull-down transistor portion(30), a second pull-up and pull-down transistor portion(60), a signal control portion(10), a voltage control portion(20) and feedback portion(40). The first pull-up and pull-down transistor portion pulls up and pulls down the output terminal of the output buffer. The second pull-up and pull-down transistor portion pulls up and pulls down the output terminal after a predetermined time elapses when the first pull-up and pull-down transistor portion enables. The signal control portion generates a gate signal of the first and second pull-up and pull-down transistor portions by combining a first and second input signals and an enable signal. The voltage control portion lowers the voltage level of the output signal of the signal control portion and outputs the lowered signal into the gate of the first pull-up and pull-down transistor portion. The feedback portion generates a gate signal of the second pull-up and pull-down transistor portion by combining a signal fed back from the output terminal and the output signal of the signal control portion.
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