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 the previously proposed single-ended Nairn cell, this principle does not lead to low harmonic distortion because the distortion is also a function of the signal-independent clock injection. SPICE simulations indicate that the proposed cell achieves a distortion level of -90 dB to -100 dB, which is about two orders of magnitude below the level achieved with basic switched-current cells. The performance of the proposed cell is near that of state-of-the-art switched-capacitor circuits.