| Traditionally power supplies have used diodes as rectifiers. This approach has become inadequate for space applications, however, because of the increasing need for greater power supply efficiency. One alternative to the use of Schottky diodes in power supplies is the use of synchronous rectifiers. The purpose of this thesis is to analyze several synchronous rectifier designs and show that it is feasible to develop a synchronous rectifier that results in greater power supply efficiency than is presently available from power supplies using Schottky diodes. Both NMOS and CMOS circuits were studied. Design analysis included variations in (a) comparator biasing, (b) comparator size, (c) driver scaling, (d) output FET size, and (e) power supply capacitor size. Analysis of the data indicated that it is possible to fabricate a synchronous rectifier which will result in a power supply with greater efficiency than one using a Schottky diode. |
