| 摘要 |
PURPOSE:To achieve high speed and low power supply voltage, by providig a plurality of blocks consisting of a plurality of current division circuits and weighting and adding the output current of each block. CONSTITUTION:Current 2I flows by constant current circuit 50, and the current 2I is divided into two Is at a current division circuit 51 and given to current division circuits 2, 52. The divided current of the circuits 2, 52 is respectively given to current division circuits 3-8, 53-58 in cascade connection to obtain wieghted to I/2- I/2<7>, to be given to switches 17-30 to which digital signals are applied. An output current i1 of the switches 17-23 and an output current i2 of switches 24-30 are weighted at a current synthesis circuit 49 to obtain i1+i2/2<7> at a terminal 31. Thus, since a current switched at a switch 30 is greater, the speed of the switch 30 is faster. |
