Switched-capacitors versus switched-currents: a theoretical comparison [in CMOS]

A comparative study between switched-capacitors (SC) and switched-current (SI), using speed, power and signal-to-noise-ratio as performance vectors, is presented. To no one's surprise, the analysis suggests that SC outperforms SI considerably for the past and present technologies. However, as processing heads towards lower power supply voltages the performance of SC falls steadily while that of SI remains almost constant. Ultimately, there is a fundamental tendency for the performance gap between SC and SI to steadily reduce and SI performance is expected to match and surpass that of SC during the course of the next decade.