Design of a Current Feedback Instrumentation Amplifier for Resistive Sensor Readout Interface

This paper describes the design of a fully differential high gain Current Feedback Instrumentation Amplifier (CFIA) suitable for front-end interface of resistive sensor-based systems. The proposed design can function with an input common-mode voltage range that includes the negative supply rail. Simulation results show that the proposed CFIA achieves an open loop gain of 115dB, unity gain bandwidth of 19MHz and a CMRR of 95dB. The design has been implemented in the SCL 0.18µm CMOS process and operates with a 5V supply voltage.