UBC Theses and Dissertations
An analog-to-digital conversion circuit using a stack of tunnel diodes each constructed from the same material Strong, James Thomas
This thesis describes a mathematical-graphical analysis and some analog computer simulation studies that were carried out to determine the feasibility of a proposed circuit to be used for analog-to-digital conversion. The circuit analysed and simulated contains a stack of tunnel diodes which are constructed from the same type of semiconductor material. The switching characteristics of this circuit are controlled primarily by the ratios and the values of the capacitances which shunt the individual tunnel diodes and to a lesser extent by the interdiode capacitances. This is revealed in a study of the effects of different circuit parameter variation A two tunnel diode stack circuit (two bits of information capacity) is analysed by studying the nature of the switching trajectories in the proximity of the singular points of the equations describing -the circuit operation. Three different modes of operation, each of which differs in the manner in which the 11 state is reached, are revealed for this circuit. The analysis indicates a feature of the circuit which can be used to determine the final state of the circuit before steady state conditions have been reached. An extension of the two tunnel diode stack circuit to one containing three tunnel diodes yielded eight stable and accessible states. This indicates that the circuit proposed will be able to realize 2[superscript n] states with n tunnel diodes. It is shown that different interdiode capacitance connections will facilitate the achievement of this result.
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