A Peak-Injection CLS Technique for PVT-Robust Switched-Capacitor Amplifier

This brief proposes a peak-injection correlated-level shifting (PICLS) technique to enhance the equivalent gain of an amplifier against process, voltage, and temperature (PVT) variations, thereby improving robustness. Furthermore, PICLS outperforms other CLS techniques in both energy efficiency and circuit complexity by eliminating the need for complex optimum-gain-detection or loop-cutoff circuits. To validate the technique, a PICLS-based inverter-switched-capacitor (SC) amplifier was implemented in 180-nm CMOS. Compared to the conventional CLS, PICLS achieves at least 23% higher equivalent gain across PVT conditions, with a total harmonic distortion (THD) of 0.002339% at 1.390625 kHz. The spurious-free dynamic range (SFDR) reaches 95.1 dB, a 17 dB improvement over the conventional CLS. When applied to an integrator, PICLS reduces output error by 69.2% after 15 integrations. The layout area is 0.052216 mm2.