| 摘要 |
PROBLEM TO BE SOLVED: To reduce a deterioration with age of a reference voltage Vref of a reference voltage generating circuit. SOLUTION: N-channel type MOSFETs Q1, Q2 have the same structure, and each of them has a floating gate and a control gate, and each initial threshold voltage is at an enhancement side. In both of the MOSFETs Q1, Q2, holes are injected in the floating gate. The MOSFET Q1 is made into a depression type. The MOSFET Q2 is made into an enhancement type since less amount of holes than those of the MOSFET Q1 are injected in the MOSFET Q2. A fixed current nature of the MOSFET Q1 is utilized, and the MOSFET Q2 is operated by the fixed current, and a voltage generated in the MOSFET Q2 is taken out as the reference voltage. COPYRIGHT: (C)2008,JPO&INPIT
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