Application of Integrated Circuits to Industrial Control Systems with High-Noise Environments

A definition of both dc and ac noise margin is presented and used to compare the noise sensitivity of various logic devices. For integrated circuit applications in very high-noise environments, a systematic design method is proposed that produces noise immune systems. The method, which is based on the flow table approach for sequential circuits, gives the location of a minimum number of slow gates or slow-down networks, while critical race conditions are easily identified and eliminated.