SLVAFG6A December 2022 – November 2023 TPS25762-Q1 , TPS25772-Q1
This section provides examples of power distribution when the Source ports are in Hybrid Mode. Table 5-10 shows the configurable SPM Engine parameters used in this section's example. Table 5-11 shows the Hybrid Mode parameters used in the power distribution method.
SPM Engine Parameters | Configuration | Description |
---|---|---|
Total USB VBUS Power (System Max Power) | 54 W(1) | Total system power capacity allocated for Port A and B |
Port A Max Power | 45 W | Maximum Port A Power |
Port B Max Power | 45 W | Maximum Port B Power |
Port A Min Power | 9 W | Minimum Port A power |
Port B Min Power | 9 W | Minimum Port B power |
Assured Mode(2) | Max Init Power | Source initially sends Source Capabilities advertising max power |
Fair Share Power Policy Parameters | Value | Description |
---|---|---|
Equally Divided System Power | 54/2=27 W | Equally divided Total USB VBUS power that is distributed to each
port when two PD-Sinks are connected: Total USB VBUS Power / Total number of ports. |
Single Port Max Power Capacity | 54-9 W=45 W | System Max Power - Port Min Power (limited up to Port Max Power) |
Non-PD USB-C Power | 15 W | USB Type-C 5 V output for non-PD based USB Type-C charging |
Three scenarios of Hybrid Mode power distribution are listed in Table 5-12 as examples.
Port A | Port B | |
---|---|---|
Initially Allocated | 27 W | 27 W |
Scenario 1: Port A is unconnected. Port B connects to a Sink that requires 45 W. | ||
Power Required by Sink | 45 W | |
Power Distributed to Sink | 45 W | |
Scenario 2: Port A connects to a Sink that also requires 45 W. | ||
Power Required by Sinks | 45 W | 45 W |
Power Distributed to Sinks | 27 W | 27 W |
Scenario 3: Port B's Port Partner is replaced with a non-PD Sink. | ||
Power Required by Sink | 45 W | |
Power Distributed to Sinks(1) | 39 W | 15 W |
Figure 5-11, Figure 5-12, and Figure 5-13 show the PD negotiation flow following the Hybrid Mode examples from Scenario 1, Scenario 2, and Scenario 3 of Table 5-12, respectively.