Barriers vs Isolators


For the majority of IS applications there is a choice of either a barrier or an isolator. MTL offers a comprehensive range of both technologies in DIN rail and backplane mounting formats. The main reasons for choosing barriers or isolators are listed below but for a full, comprehensive explanation please refer to our technical paper - TP1113 - which goes into the detail of each IS technology.
Barriers	Isolators

If existing system is predominantly barriers	If existing system is predominantly isolators
Simple	Complex ~ lower MTBF
Versatile	Application specific
Low dissipation	High dissipation (2VA)
Loop-powered	Separate power supply
Restricted voltage available in hazardous area	Higher voltage (power) available in hazardous and safe area
Higher packing density	Lower packing density
Safety earth fundamental	Safety earth has reduced significance
Lower cost	Higher cost
Good frequency response <100KHz>	Limited frequency response
Higher accuracy and linearity <0.1%>	Lower accuracy and linearity <0.25%>
Imposes a '0' volt level on system	Complete isolation between signals
More vulnerable to lightning and other surges	Less vulnerable to lightning and other surges