Fully differential CMOS current memory cell for analog-to-digital converters

This paper presents a current memory cell (CMC) which can be used as basic elements of current pipeline analog-to-digital converter stages. This CMC is based on a fully differential structure which uses the Miller effect to reduce charge-injection errors. Using a 0.35μm 3.3V CMOS process, results show that the signal-dependent charge-injection error is less than 20nA for [-200μA;200μA] dynamic input current range. The acquisition time for a 200μ input step transition to achieve a 14 bit settling accuracy is 22ns. The active chip area and the power consumption of the proposed CMC are about 0.042mm² and 6mW, respectively.