| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a data output circuit sufficiently strong to an electrostatic discharge stress without deteriorating the operating characteristic. SOLUTION: While a ground wire VSS4IO for output drivers 7, 9 is separated from a ground wire VSS4P for another circuit 200 by an impedance Z4, a diode circuit 100 connecting these ground wires VSS4IO and VSS4P is provided to a forward direction faced from the VSS4P to the VSS4IO. When a potential difference between the ground wires becomes more than a built-in voltage of the diode circuit 100, the two ground wires are connected with a very low impedance component through the diode circuit 100, as the result a potential difference between a node DOD4 and an output terminal I/O4 generates only the built-in voltage and does not reach to generate an ESD stress. On the other hand, in the case that noise is resonated with the ground wire VSS4IO, since the diode circuit 100 is connected inversely, noise from the output drivers 7, 9 is not transmitted to the other circuit 200.</p> |
