High CMRR, Low Power and Wideband Current-Mode Instrumentation Amplifier

The current-mode instrumentation amplifier based on second-generation current conveyors (CCII) offers many benefits over conventional instrumentation amplifier architectures. It does not need any matched components to achieve high CMRR and its bandwidth is not gain-bandwidth product limited. Therefore, the wideband CMOS current conveyor has been used in this structure. HSPICE simulations have shown that its performance is quite satisfactory for wideband current-mode signal processing. Furthermore, different CMRR enhancement techniques of current-mode instrumentation amplifiers are discussed. The new simulated instrumentation amplifier provides approximately 40 dB of improvement on the high-frequency CMRR up to the 3-dB corner frequency and even higher. In addition, composite conveyor techniques improving the instrumentation amplifier performance are presented