SLVAFG6A December 2022 – November 2023 TPS25762-Q1 , TPS25772-Q1
The Assured Capacity Policy is where the sum of the Port Max Power, as designed, is equal to the Total USB VBUS Power.
When the Source ports are configured as Assured Capacity, Port Max Power is guaranteed and each port is able to deliver up to its Port Max Power independent of the second port's status. An example of the Assured Capacity Policy is shown in Figure 3-3 where the Total USB VBUS Power is 60W, Port A's Max Power is 40W, and Port B's Max Power is 20W.
The TPS25772-Q1 dual-port PD controller supports two Assured Capacity power modes configurable using the TPS257xx-Q1-GUI. The options are:
The recommendation is to always configure for Max Init Power (default GUI setting) unless a different operational mode is preferred based on system requirements. Figure 3-4 and Figure 3-5 show the Assured Capacity Policy selection in the GUI's Simple Configuration view and Advanced Configuration view.
See Section 5.1 for example scenarios of the Assured Capacity Policy to better understand how system power is allocated and distributed when this SPM Power Policy is selected.