ISIS: A Fail-Safe Interface Realized in Smart Power Technology

Actuators of safety critical systems must be driven by fail-safe signals. Under a failure in the system, such a signal has to be either on the correct state or on the safe state. This paper describes a fail-safe interface able to generate the fail-safe signals required in this context. The circuit is realized into a smart-power technology allowing delivering fail-safe signals having the power characteristics required in a railway system. It can replace traditional fail-safe interfaces realized by means of bulky and expensive discreet components.