Reference circuit capable of supplying low voltage precisely

摘要

A reference voltage circuit is provided which includes a first MOS transistor including a first gate, and a second MOS transistor including a second gate. The first gate includes a first conductive type impurity with a concentration less than or equal to 1x10¹² cm^-3, or no impurity. The second gate includes the first conductive type impurity or a second conductive type impurity with a concentration greater than or equal to 1x10¹⁹ cm^-3. The reference voltage circuit generates a predetermined reference voltage by utilizing a difference of work functions between the first and second transistors so as to have no temperature dependence.