| 摘要 |
PURPOSE:To vary easily and electrically the output of a constant voltage circuit after the integrated circuit is manufactured, by using floating gate IGFETs as one of constant voltage circuit or plural IGFETs so that the threshold value is controlled. CONSTITUTION:An IGFET6 is of depletion type and composed of a floating gate IGFET whose threshold value is variable or two-layered insulation system IGFET of MNOS structure, etc. An IGFET7 is of floating gate type or represents the interface between two insulating films under the gate, and the threshold value is variable. The drain of this IGFET6 is connected to the plus side VDD 3 of a power source, and the gate and source are connected to the gate and drain of the other enhancement IGFET2, whose source is connected to the minus side VSS4 of the power source, so that a constant voltage output is delivered between a terminal 5 and the power source VSS4. |
