Quality of the DC Power Supply for Modern Telecommunication Systems

Quality can be defined as "fitness for purpose". With all telecommunications equipment in a modern UK centre powered from the -48V dc power supply, it has to be of a specified quality. Any unspecified characteristics could cause widespread misoperation or damage. A new dc distribution system has been developed, primarily for new equipment systems which deploy large numbers of dc-dc switching converters. Such equipment is inherently tolerant of wide input voltage limits and low frequency noise voltages but is intolerant of high-energy voltage transients. An investigation has been carried out to restate the critical factors affecting the design of equipment on both sides of the power supply interface.