ABSTRACT
Monolithic analog switches have proven to be a very reliable means of controlling signals through countless device-hours of manufacturer’s qualification and user’s applications. Analog switches are found in many applications that require very high projected reliability levels, including MIL-M-38510 compliant JAN and /883, which describe some of the highest levels of reliability qualifications required by the military. “Latch-up” is a phenomenon that plagued the first few generations of CMOS analog switches. Various techniques have been applied to analog switch process and design to provide overvoltage protection. These include the use of on-chip series resistors, the use of alternate switch technologies such as Junction Field Effect Transistor or D/CMOS, and designing new switch topologies in standard CMOS such as the use of series Field Effect Transistors to block currents from overvoltages and other faults. A simple form of protection is to add current-limiting resistors in series with any switch channel that looks outside of the system.
