An improved current-mode instrumentation amplifier with bandwidth independent of gain

A modification in current-mode instrumentation amplifier topology proposed in Electronics Letters, vol. 25, p.470-471 (1989) is described, and a detailed analytical analysis is given to show its superiority. The proposed circuit design is simple and easy to construct from readily available IC AD844 from Analog Devices. The proposed circuit features high CMRR without requiring well-matched resistors. Moreover, high differential gain and bandwidth can be achieved simultaneously. Experimental as well as simulation results are given in support of theoretical conclusions