CMOS LowVoltage Indirect Current Feedback Instrumentation Amplifiers With Improved Performance Indirect current feedback (ICF) is a very common operation principle used in the design of CMOS instrumentation amplifiers (IA). The input and output transconductors required in an ICF IA usually consist on resistivedegenerated simple differential pairs. In this contribution conventional sourcefollower (SF) structures used in IA transconductors are replaced by flippedvoltagefollower (FVF) and supersourcefollower (SSF) cells, respectively. As a result, the overall performance and efficiency of the IA is enhanced with a minimum cost. The principle of operation governing CMRR is also analyzed and its behavior is confirmed by means of extensive simulations. A singlestage IA with a fixed voltage gain equal to 10 VV has been designed in  0.35boldsymbolmu mathbfm  standard CMOS technology to operate with 1.8 V supply. Simulation results show improved metrics in terms of voltage gain accuracy, while the overall performance of the IA is comparable to other contributions in the literature.

CMOS Differential Stage with Improved DC Gain, CMRR and PSRR Performance New circuit solutions able to operate under sub1V supplies must be developed by analog designer to counteract the low intrinsic gain and limited rejection to commonmode and power supply disturbances offered by nanometer CMOS technologies. In this communication, an approach originally developed as a commonmode control loop for bodydriven amplifiers, is exploited in the active load of a sourcecoupled pair to remarkably improve its smallsignal performance. Simulations on a 65nm design supplied from 0.75V show a nominal increase in differential DC gain, CMRR and PSRR of 20 dB, 29 dB and 32 dB, respectively, as compared to the standard solution.