SC and SI techniques performances faced with technological advances in CMOS

摘要

This paper proposes to compare switched-capacitors (SC) and switched-currents (SI) technique performances faced with technological advances. Three cells of identical low complexity are analysed and the following performance factors are theoretically evaluated: minimal supply voltage, signal input range, static accuracy, maximal sampling rate, signal to noise ratio and power dissipation. Then, a figure-of-merit is formed and its evolution is reported as a function of time. It shows that SI circuits are less sensitive to the supply voltage scaling than SC circuits as long as transistors operate in the strong inversion region. But, as gate-source overdrive is finally reduced with supply voltage, SNR/sub SI/ decreases down to a limit calculated in weak inversion mode.