This reference design provides a competitive
approach to multiport, high-power applications.
In a multiport PSE system, the system-level software is the biggest challenge. The software handles complicated situations and addresses the following challenges:
- The power supply is typically not able to support
all ports with a full load due to size and cost constraints. The system software
manages the port power with priority to keep the total power consumption below
the power budget.
- There are multiple power supplies in the system.
These power supplies can be in sharing mode or backup mode. The system software
shuts down low-priority ports fast enough to keep the total power consumption
below the remaining power budget.
- There are some legacy PD devices that do not present the standard PoE PD signature. The system software finds a way to supply power to these devices.
- System software limits the port power based on the PD class levels or host configuration.
- When there are load-step changes on multiple ports, the system software acts quickly enough to keep the power consumption below the power budget.