A Transient-Enhanced Autonomous Current Adaptation Buffer Amplifier

This brief proposes a transient enhanced autonomous current adaptation buffer amplifier (ACABA) that effectively resolves the slew rate degradation problem observed in the previous design. The proposed circuit enhances the transient responses, achieving faster step responses, superior linearity, and higher power efficiency. The cause of the degradation in the previous work has been elucidated, and a transient enhancement circuit is proposed to circumvent the slewing bottleneck. A prototype chip has been designed and fabricated in a $0.35 \mu {\mathrm{ m}}$ CMOS process. From measurements, the proposed circuit improves settling time by 62.1%, enhances slew rate by 3.1 times, and reduces total harmonic distortion (THD) by 17 dB without extra static power consumption. With a $2.5V$ supply voltage, the proposed buffer amplifier allows a maximum input signal amplitude of 2.3V with the THD below −60 dB. Furthermore, the enhanced buffer amplifier exhibits the best power efficiency in both small-signal and large-signal performance compared to other state-of-the-art designs.