Design of 1V Rail to Rail Operation Amplifier Based on a Novel Level Shift Configuration

Abstract—In this paper a 1-V Rail-to-Rail operational amplifier is presented. Since the designed circuit adopts two complementary input differential pairs, one of which is connected to inputs through dual-level voltage shift by four source followers, the trans-conductance could be constant overall the common input range. Considering the low supply voltage and enough capability to drive large loads, a feedback class-AB structure is available in the output stage. Under 1V power supply, the whole circuit is simulated with 2pF load-capacitance and 10K load-resistance by HSPICE in the SMIC 0.18um process. The simulation results indicate that the low-frequency voltage gain is 72dB while phase margin is 61.6°, the unit frequency bandwidth is 3.1MHz, and the power dissipation only 62uW. Index Terms—low-voltage, low-power, level voltage shift, operational amplifier I