Operational Trans-conductance Amplifier by Current Recycling Branches for Ultra Low Power Application

In this paper an ultra-low power two stage improved operational trans_conductance amplifier based on folded cascode is designed. The proposed operational trans_conductance amplifier operates in weak inversion region.  The use of two folded branches in the signal amplification path for the first stage and the new feed_forward compensation path with low bias current on the second stage in this proposed amplifier increases the DC gain, unity gain frequency, slew rate and decreases the input referred noise. The simulation results in a TSMC 0.18µm CMOS technology it shows that the proposed operational trans_conductance amplifier has unity gain bandwidth of 117 KHz, and consumes 195 nW power from a 0.6 V supply voltage with DC gain of 101.4 dB.