A Swing- and Gain-Enhanced Mirrored Dynamic Amplifier

Abstract

This brief presents a Mirrored Dynamic Amplifier (MDA) to enhance the swing and gain of prior art dynamic amplifiers (DAs). Instead of compensating the charge loss in the load capacitors due to the common-mode current, this technique resolves the dependency between common-mode and differential-mode currents. The differential and regulated common-mode currents are mirrored to the output branch for integration on the load capacitors. Furthermore, the output branch is made of only one transistor, which makes the proposed architecture to benefit from large output swing. An output swing of 1.272Vppdiff can be achieved with a supply voltage of 1.2V. In addition, a pre-discharge linearization technique is presented to compensate for nonlinearity induced by the current regulation mechanism, that results in an average improvement of 6 dB in THD. The proposed DA is designed and verified in a 65nm CMOS process. Post-layout simulation results show that gains of $16\times $ and $32\times $ can be achieved, along with output swings of 640 mVppdiff and 800 mVppdiff, respectively, while maintaining THDs better than −62 dB. A noise analysis and a detailed comparison of the proposed MDA with a few state-of-the-art designs are also elaborated.