| 摘要 |
PROBLEM TO BE SOLVED: To protect the internal circuit of a hold circuit with an external capacitor, for holding from surge voltage entering through an input terminal connected to the capacitor, and to protect the holding voltage of the capacitor from the influence of a protection circuit. SOLUTION: Between the input terminal (N1) and the source potential (Vcc) of an integrated circuit connected to the capacitor, a first PMOS transistor (Q3) is inserted with the source and the gate connected to the source potential and the drain connected to the input terminal. Between the input terminal and the ground potential (GND), a second PMOS transistor (Q4), having the same structure and the same size as those of the first PMOS transistor, is inserted with the source and the gate connected to the input terminal and the drain connected to the ground potential. COPYRIGHT: (C)2005,JPO&NCIPI
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