A Robust Overdesign Prevention Circuit Technique Under Widely Varying Ambient Conditions

An automatic aspect ratio trimming technique is presented to ensure an optimal design insensitive to the variations in process, voltage, and temperature (PVT). The traditional methodology, which works on the principle of designing for the worst case with a fixed aspect ratio (with one-time trimming), results in an overdesign in the nominal operating conditions, which has been targeted in this work. The proposed design approach is compared with the conventional through an illustrative example of optimally designing a simple differential pair for minimum parasitic capacitance and total harmonic distortion. The simulation results showed that the proposed methodology outperforms the conventional at all corners, ensuring an optimal design in each corner while adding little overhead.