Inverter-Based Amplifier with Active Frequency Compensation and Adaptive Voltage Scaling

This paper presents and compares two single-ended inverter-based amplifier topologies, with and without active frequency compensation, both with the same area and the same biasing circuits. Thanks to adaptive voltage scaling and body biasing, the proposed circuits show robustness to the effect of the process, voltage, and temperature (PVT) variations. In particular, post-layout simulations referring to 180 nm technology process show a supply voltage insensitivity in the range from 6 V down to 2.5 V. The possibility of being robust to uncertain and unreliable supply voltage changes suppresses the need for an additional voltage reference and makes the proposed circuits well-suited for energy-harvesting systems-on-chip.