| 摘要 |
PURPOSE:To easily constitute a high-accuracy constant current source group while making the width of grounding wiring narrower than before and, therefore, reducing chip area by applying a potential lower than the source potential of an N-channel MOS field effect transistor(FET) present in each well. CONSTITUTION:When the source potentials of N-channel transistors(TR) 101-107 for constant current generation need to be raised from the ground zero potential because their grounding wiring is narrow, the potentials of wells are controlled according to the raising quantity to control the threshold values of the respective TRs 101-107 for constant current generation. Consequently, the current quantities of the respective TRs for constant current generation can be adjusted with high accuracy and even if the wiring is narrow, the constant current source group is composed of the TRs for constant current generation having current values nearly proportional to the gate sizes of the TRs.
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