| 摘要 |
PURPOSE:To make compact a decoder circuit and to improve an integration by disposing a power source control circuit of a logical gate generating a selecting signal according to an address signal outside a decoder. CONSTITUTION:A transistor TrQ11 of a power source control circuit 11 make a control signal -phi a gate input, connects a drain to a high potential Vcc, and a source is connected to a drain of an output node N3 and a TrQ12, and a control signal phi is inputted to a gate of the TrQ12. In a word, making all decoder output H, a line all selecting mode, if the signal phi=H, the TrQ12 is turned on, a potential of a connecting node maling the signal phi=L a gate input is lowered and a voltage of the output node N3 of the circuit 11 is lowered to OV. Accordingly, an input N1 of a CMOS inverter and the output node N3 of a NAND gate of all decoder circuits goes to L and a voltage of an output terminal 15 goes to H. Thereby, the decoder circuit can be made compact and an integration can be improved.
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