| 摘要 |
PROBLEM TO BE SOLVED: To provide a power-on reset circuit which can be used even for a low power consumption and low power voltage semiconductor device. SOLUTION: In a POR circuit 1, when power is turned on, the output signal of an inverter 35 reaches the level 'H', an N-channel MOS transistor 3 is brought into conduction and the potential V1 of a node N1 becomes a potential of the power voltage VDD divided by the continuity resistance R2 of a P-channel MOS transistor 2 and the continuity resistance R3 of the N-channel MOS transistor 3. The power voltage VDD=Vres, when a signal POR# is reversed, is Vres=1.33 V when the threshold voltage of an inverter 15 is 0.8 V and R2:R3=2:3. Accordingly, the POR circuit 1 can be adequately used even for a MOS transistor of 1.5 V type exhibiting a threshold voltage of 0.8 V.
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