Implementation and Analysis of Current Reuse Technique based Stacked Inverter for AFE Cardiac Amplifier, Bio-Signal Recording System (ECG)

The paper is focused on novel design of current reuse technique based stacked inverter stage-4 amplifier .In order to achieve high performance amplifier and to achieve efficiency in terms to obtain refined signal quality, low noise and low power consumption, the architecture is proposed as analog front end instrumentation amplifier which plays vital role in determining overall efficiency of bio-signal recording system (ECG). The four stage stacked inverter design is based upon stacking of four inverters in which same bias current is shared. The common gates branches originating from the stacked amplifiers, such that current signal is aggregated from all eight pairs. Thus the overall trans-conductance of the circuit obtained is 8gm. The design is operated at 1-V power supply and implemented in 0.18 micron technology which showcase the gain of 49.57dB, CMRR is 85.29dB, noise is 150uV/√Hz @300Hz and obtained power efficiency of 1.89x10^-11W.