A Novel Low Voltage, Low Power and High Gain Operational Amplifier Using Negative Resistance and Self Cascode Transistors

In this work a low power, low voltage and high gain operational amplifier is proposed. For this purpose a negative resistance structure is used in parallel with output to improve the achievable gain. Because of using self cascode transistors in the output, the proposed structure remains approximately constant in a relatively large output voltage swing causing an invariable gain. To evaluate the proposed method an op amp was designed in 0.18μm CMOS technology. The simulation  results showed a gain of 84dB, unity gain bandwidth of 12.45MHz and phase margin of 81 degree; with 1V power supply and 1pF load capacitor.