Opto devices are inherently limited. At the core of an opto device is an LED which has a large output variation over input current, temperature, and age. These variations reduce the operating performance of the devices over their lifetime, which causes additional design complexity for system engineers and reduces the life expectancy. The major concern with optos is long-term reliability. Because of the aging effects, optos are often specified to last less than 10 years. This is a serious problem for modern industrial system designers who want to provide 20+ year warranties to their customers. Switching rates are also limited on optos because of the slow and asymmetric switching properties of the LED. Another serious concern is the common mode transient immunity. Poor immunity is due to the inherent high-parasitic capacitance of the opto architecture and can lead to incorrect data being coupled across the isolation barrier. Finally, the internal LED on the optos requires a high driver current to turn on, causing high power consumption. These limitations on optos can be addressed in various ways; however, improving one of the parameters invariably degrades another aspect of the opto. For instance, the CMTI can be improved by driving the LED with a higher current, but then the power consumption is higher and the lifetime of the device is reduced. Optos limit what the system designer can do.