Various current-mode and voltage-mode instrumentation amplifier topologies suitable for integration

In this paper, four instrumentation amplifier (IA) topologies, one of which is current-mode (CM) while the others are voltage-mode (VM), are presented. Three of the IAs use one to two current feedback operational amplifiers (CFOAs) while the other one employs only a single NMOS transistor. One of the IA circuits, given as an example, is simple while others are novel. The CM IA is composed of only grounded resistors which have some advantages in integrated circuit (IC) process. Non-ideality effects such as non-ideal gain and parasitic impedances on the performance of introduced IAs are discussed. In order to show the performance of the circuits, we perform experimental tests and simulations by using SPICE program. © World Scientific Publishing Company