Instrumentation Amplifiers and Operational Floating Amplifiers

With the definition of universal active devices in Chap. 1 we have seen that the operational floating amplifier (OFA) is the most universal active device, even more universal than the operational voltage amplifier (OVA), abbreviated to OA or OpAmp, because of its most wide usage. The OpAmp provides us with accurate output voltage control. Additionally, the OFA provides us with accurate control of an output current, independently of the output voltage. So with the OFA we are able to create controlled current sources. These can be used for the transmission of current signals independent of ground or reference voltage differences and for instrumentation amplifier applications mentioned in Sect. 3.4 (Huijsing, Analog Integr. Circ. Signal Process 4(2):115–129, 1993).