| 摘要 |
PURPOSE:To prevent the noise of a power supply, which is generated in an output circuit, from propagating to other circuits and to prevent the occurrence of any malfunction of an internal circuit by a method wherein the power supply wiring of the output circuit is isolated from the power supply wiring of the internal circuit and a substrate potential supply wiring. CONSTITUTION:An output circuit 103 is supplied power from a power supply VDD through pads P12 and P15 and power wirings 107 and 108 and an internal circuit 101 and a sense amplifier 102 are respectively supplied power from the power supply VDD through pads P11 and P16 and power wirings 105 and 106. A substrate potential is given by a pad P14 and a wiring 109. When the circuit 103 now discharges a charge of a load capacity C11, a current I1 flows through the wiring 108 and noise is generated. A potential at a point A1 of the wiring 108 fluctuates, but a potential at a point B1 does not fluctuate because the wiring 108 is isolated from the wirings 106 and 109. Accordingly, the noise generated in the circuit 103 does not propagate to the circuit 101 and the circuit 101 does never cause any malfunction. |
