US Patent 7362127 Driver circuit

A driver circuit for driving a device or circuit disposed after it comprises a plurality of driving transistors connected in parallel, a selection unit for selecting one or more groups from a plurality of groups to each of which driving transistors having a power base of two with the same polarity belong and in which the number of driving transistors belonging to each group is different and a driving unit for driving driving transistors belonging to the group selected by the selection unit.