This Application Note presents the design of a power system required to convert the -48V bus to multiple voltages typically required by communication equipment such as network processors, DSPs, and miscellaneous ASICs. Included is a review of the entire design with both power management and power conversion blocks, focusing on areas where difficulties often arise. The power management is implemented using a hot swap controller SMH4804, a quad power supply manager SMT4004 and two dual 10-bit nonvolatile DACPOTTMs SMP9210 for trimming. The power conversion block is built using Power-One™s QHS series of 50A quarterbricks. Guidelines and optional solutions are provided to increase the likelihood of a trouble-free system power design.