A 0.3‐V 62‐dB Bulk‐Driven OTA With Hybrid Frequency Compensation in 65 nm CMOS

ABSTRACT This paper presents a novel 65‐nm CMOS ultra‐low‐voltage (ULV) operational transconductance amplifier (OTA) design. The proposed architecture integrates partial positive feedback (PPF) with a hybrid frequency compensation technique that combines current‐buffer and Miller compensation approaches. This hybrid compensation effectively mitigates the primary limitation of PPF‐based OTAs, that is, their sensitivity to transistor mismatch. Operating at a supply voltage of 0.3 V and consuming just 23.7 nW of power, the two‐stage OTA achieves a rail‐to‐rail input common‐mode range, a DC voltage gain of 61.7 dB, and a gain‐bandwidth product of 12.7 kHz with a 20‐pF load capacitance.