Distributed Power Architecture

The distributed power supply architecture is a power distribution system in which the conversion to low voltages only takes place on site on the respective module. A classic DPA (Distributed Power Architecture) consists of an AC/DC power supply that converts the mains voltage to a relatively high DC supply voltage (typically 48V bus), which in turn supplies a series of isolated DC/DC converters in brick format, each of which supplies a low-voltage load (0.7V-3.3V). The aim is to achieve more efficient energy conversion.

The power supply in complex, modern circuits supplies components such as high-performance ICs, microcontrollers, DSPs and FPGAs that require different supply voltages. Therefore, the use of Distributed Power Architecture (DPA) started about 15 years ago. In general, the greater the difference between the input and output voltages of a DC/DC converter, the lower the efficiency of the energy conversion. The output voltage of a front-end power supply with 48V galvanically isolated to 3.3V or below is difficult to convert in terms of efficiency and accuracy, so this structure developed into the Intermediate Bus Architecture (IBA) commonly used today.

The IBA is a distributed power supply architecture with an additional DC/DC voltage conversion layer. Here, an AC/DC power supply feeds an isolated 24V or 48V DC/DC bus (IBC) converter, which in turn delivers 5V to 14V to the non-isolated PoL (point of load) converters located directly at the load, providing the required voltage for the load circuits.

This saves the cost of isolating each last level DC/DC converter. Another advantage of the IBA is the power conversion close to the consumer. By decreasing the operating voltage of the loads with ever smaller process nodes, the processing power of the ICs can be increased. By increasing the efficiency of the ICs and lower operating voltages, the current requirement increases. With long PCB tracks or system cabling, a power supply located far from the load would lead to extremely high I2R losses and instability. For maximum system efficiency, the last conversion should therefore take place as close to the load as possible. Back