An improved non-linear current recycling folded cascode OTA with cascode self-biasing

Abstract An improved non-linear current recycling folded cascode operational transconductance amplifier with cascode self-biasing is presented in this paper. To improve the gain-bandwidth and slew rate of traditional current recycling folded cascode amplifier, the adaptive biasing class-AB input stage and non-linear current recycling output stage are utilized to improve the effective transconductance and maximum output current. In addition, a cascode self-biasing structure is applied to the output stage to prevent the PMOS current mirror from entering the linear region during the large signal current. Both the conventional and the proposed current recycling folded cascode amplifier are all designed on SMIC 0.18 μ m. The simulation results show that the proposed non-linear current recycling amplifier achieves 2.1 times the gain-bandwidth and 5.4 times the slew rate that of conventional current recycling amplifier, with only 25 % extra power consumption.