A nonlinear current mirror method for improving the slew rate of subthreshold current recycling OTAs.

A proposed ultra-high slew rate current recycling folded cascode operational transconductance amplifier (OTA) working in the subthreshold region is presented. By employing adaptive biasing and the proposed positive-feedback nonlinear current mirror techniques, it not only forces the charge or discharge path to enter the strong inversion region during slewing, but also provides an ultra-high output current, leading to a significant boost in the slew rate. The simulation results of the two OTAs designed in SMIC 0.18 μ m CMOS process demonstrate that the slew rate of our proposed OTA is enhanced 387 times than that of the conventional counterpart with the same power. [ABSTRACT FROM AUTHOR]