Putting power forward
Flexibility and future-proofing
While it makes sense to establish the power distribution architecture early in the project, designers also need flexibility to be able to modify aspects such as POL output power, rail voltages or power-up and power-down sequencing as the system design evolves.
Digital power modules give designers the flexibility they need. Unlike a traditional analog power architecture, which is fixed and can require hardware or wiring changes if modifications are needed, digital modules can be reprogrammed thereby allowing parameters to be adjusted quickly and at low cost (Figure 2). Voltage rail sequencing, for example, can be easily configured and reconfigured with digital voltage regulators (Figure 3). Digital modules also require fewer external components, and so help simplify design while also relieving pressure on board real-estate.
Figure 2 Systems using a digital power architecture are extremely flexible and the site manager can access any part of the board, down to a single POL through the digital interface.
Figure 3 An example of a digital power graphical user interface. Digital power offers virtually instantaneous control of margining, monitoring operating parameters and configuring the supply.
During the course of product design and development it is recognized that changes and upgrades will occur. As has already been discussed, many of the changes and upgrades can be addressed by reconfiguring digitally controlled power modules already designed into the system and thus no physical changes are required to the host PCB or to the power delivery modules. There will be times when a physical upgrade to the original power circuit will be required.
A common reason this situation occurs is that the load current increases beyond the original specifications and thus the need for electrically larger components to supply the additional load current. One advantage of using power modules is the impact of the design upgrade to the complex and expensive host PCB can be minimized. Upgrading a power module to one with a larger output power rating often involves only moving the existing mounting holes or pads and not changing any other design feature on the host PCB.
Moreover, digital power supports an efficient “platform” approach, recognizing that system power demands will become more complicated in the future. Due diligence in decision making is vital, and choosing a power module vendor that can offer a wide choice of products helps not only to simplify changes during the project but also helps streamline the development of future product generations.