System Characteristics with Hybrid Power Modules as Embedded Power Supplies

Already at the introduction of electronic telecommunication systems, embedded power supplies (also called in-frame power, rack power or dedicated power supplies) were an important part of the system design. Depending on the structure of the system and its subsystems, there were different requirements, on i.e. power, size, output voltages and number of outputs. Throughout the years, a wide range of DC/DC-converters, have therefore been used. RIFA AB recently introduced a new type of power supply, based on hybrid technique, where the traditional open-frame DC/DC-converter has been turned into an encapsulated standard component. This paper will describe the special features obtainable in a system, where these power modules are used as embedded power supplies. Emphasis will be put on a number och characteristics, which will give increased freedom of design. The following items will be especially discussed: reliability, efficiency, ambient temperature and power/volume ratio, as these are parameters on which great development efforts have been put into the power module. This paper will also give some aspects on designing small, extending or large systems, having the possibility to use the modules separate or in parallel or series connection.