Sampled-Data System Approach to Model Time-Division Switches

The transfer function approach developed for sampled-data systems has proved to be a very powerful tool for analyzing time-division systems. 1 - 3 It yields information useful for both analysis and synthesis of the system. However, its application is often limited due to the fact that the sampling switch in a time-division circuit is different from the sampler of sampled-data-system theory. This difference can be seen from the fact that the voltage at the output side of a sampler in a sampled-data system is always zero between sampling instants, while the voltage at the output side of a sampling switch in a time-division circuit is not necessarily zero between sampling instants, if, for example, the switch is connected to a capacitor. As a consequence, one cannot treat a time-division circuit as a sampled-data system unless the sampling switch can be modeled by a sampler plus a modified system-transfer function. Of the few who have worked on time-division-system analysis, 1-9 only Desoer 1 has come close to using functional blocks to model a sampling switch, but no general approach has been developed. It is 611