Very low-distortion fully differential switched-current memory cell

This paper proposes a very low distortion fully differential switched-current memory cell, based on the opening of the memory switch at a constant voltage. We show that in two previously proposed single-ended cells this principle does not lead to low harmonic distortion, because the distortion is also a function of the signal-independent clock feedthrough. SPICE simulations indicate that the proposed cell achieves a level of distortion of about -100 db, which is more than two orders of magnitude below the level achieved with basic SI cells. The performance of the proposed cell approaches that of state-of-the-art switched-capacitor circuits