A 2.30 NEF Split-Steering Amplifier for Switched-Capacitor Circuits With −14.2-dB CM-CM Gain and 100-V/ <i>μ</i> s Slew Rate

This article presents three techniques to improve the split-steering amplifier’s (SSA) performance and robustness. At the system level, differential-mode charge neutralization (DMCN) is introduced first to reset the circuit with minimum burden. Second, a DMCN-compatible common-mode feedforward (CMFF) strategy is introduced to reduce the impact of common-mode (CM) disturbance without introducing extra noise or sacrificing the bandwidth. The above two techniques are universal and can be applied in other pseudo-differential (PD) amplifier architectures. As for circuit implementation, two ring amplifiers (RAs) with different dead zones (DZs) are paralleled with the SSA to improve the slew rate (SR) of the overall amplifier. Dynamic bias adjustment is used to increase the response speed of the RAs and ensure that they will not be activated after slewing, which is critical to keep the overall amplifier low noise. The measured results demonstrate a −14.2-dB CM-CM gain and 11.7 times SR boosting. The measured noise efficiency factor (NEF) is 2.30, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\overline {V_{n}^{2}} \cdot I_{\mathrm { supply}}$ </tex-math></inline-formula> is 1.49 times overperforming previous works.