Sinusoidal Oscillators Using Integrated-Circuit Gates

Digital integrated circuits were initially developed to meet the critical needs of aerospace applications for reduced weight and power consumption and increased reliability. Because of the continued refinement of manufacturing processes and techniques, integrated circuits are now available at prices which make their usage very attractive even in the most competitive segments of the commercial and industrial systems field. By examining specification-sheets for various digital integrated circuits that have been marketed, one can deduce that many have been designed to meet particular requirements, and that in the effort to achieve the ultimate in one characteristic, one or more of the other performance characteristics have been sacrificed. For example, circuits which have been designed for low power consumption often exhibit long propagation delays, and conversely those that were designed for primarily for high speed, consume the most power. Other characteristics such as noise margin, and production yield are important design considerations. This study is concerned with the use of integrated logic gates as the active devices in sinusoidal oscillators. Most of them are relaxation type oscillators, and are used as square wave generators for clock pulse generation. In addition to the basic gate circuits, some frequency-determining components are used, such as crystals, resistors, capacitors, and inductors. Gate oscillators without any external passive components have also been developed.