Investigation and design of a current mode instrumental amplifier

Abstract

In this project, a current-mode based instrumental amplifier (CMIA) is designed from a topology that involves 1st level asymmetrical 2nd generation current conveyor (CCII+) which involves the use of VOA supply current sensing technique: current mirrors are used to sense the output current of VOA via its power supply rails. Literature research on various current conveyor topologies to construct CMIA is carried out. Upon selection of one type of topologies, circuit characterisation, simulation and layout are performed to investigate further on this topology as an instrumental amplifier (IA) to accurately amplify a low-level signal in the presence of a large common-mode component, i.e. the common mode rejection ratio (CMRR), which is the quotient between the differential mode gain (Ad) and the common mode gain (Acm), need to be firstly higher and secondly over a wider bandwidth than me previous work.