Latch-Up, ESD, and Other Phenomena

The engineer designing an electronic system often needs to know the behavior of its components under operating conditions that are outside those usually described in the data sheets. Thus, although the latch-up effect is no longer a problem with modern CMOS circuits, a closer look at this phenomenon makes it easier for the engineer to assess realistically the risks that may arise under specific – perhaps extreme – operating conditions. The electromagnetic compatibility of integrated circuits, as well as their sensitivity and immunity to these effects, plays a significant role. Under particular operating conditions, parasitic transistors in integrated circuits can jeopardize the correct function of a component. This application report discusses latch-up, electrostatic discharge (ESD), and other phenomena, and their relationships, thereby providing designers information needed to assure the functional security of the system, even under extreme operating and environmental conditions.