Output buffer capable of adjusting current drivability and semiconductor integrated circuit device having the same

A semiconductor integrated circuit device outputting data having a first and second levels, comprising:

• an internal circuit outputting said data;
• and
• an output buffer outputting said data read from said internal circuit onto an internal node to an output node,
• said output buffer including
• a plurality of first current driving units coupled in parallel with each other between a voltage corresponding to said first level and said output node,
• each of said first current driving units forming a current path between the voltage corresponding to said first level and said output node, in accordance with a voltage of a corresponding control node;
• a plurality of second current driving units coupled in parallel with each other between a voltage corresponding to said second level and said output node,
• each of said second current driving units forming a current path between the voltage corresponding to said second level and said output node, in accordance with a voltage of a corresponding control node;
• a plurality of operation selection units provided respectively corresponding to said plurality of first and second current driving units, and each setting a corresponding one of said plurality of first and second current driving units to one of an activated state and an inactivated state in a nonvolatile manner, at least after completion of a wafer manufacturing process;
• a plurality of first signal transmission units provided respectively corresponding to said plurality of first current driving units, and each transmitting a level of said data from said internal node to a control node of a corresponding first current driving unit with a first propagation time period, when the corresponding first current driving unit is in said activated state;
• and
• a plurality of second signal transmission units provided respectively corresponding to said plurality of second current driving units, and each transmitting a level of said data from said internal node to a control node of a corresponding second current driving unit, when the corresponding second current driving unit is in said activated state.