SLVAFG6A December   2022  – November 2023 TPS25762-Q1 , TPS25772-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Terms and Abbreviations
  5. 2 SPM Engine Overview
  6. 3Multi-Port Power Allocation Policy
    1. 3.1 Assured Capacity Policy
    2. 3.2 Shared Capacity Policy
      1. 3.2.1 Fair Share Power Policy
        1. 3.2.1.1 Blind Sink Support
    3. 3.3 Hybrid Mode
  7. 4Power Foldback Policy
    1. 4.1 Thermal Foldback Operation
    2. 4.2 Engine Start or Stop Transition Management
      1. 4.2.1 Engine Start or Stop Power Foldback Operation Example
  8. 5Multi-Port Power Allocation Policy Examples
    1. 5.1 Assured Capacity Policy Example
    2. 5.2 Fair Share Power Policy Example
      1. 5.2.1 FSP Policy Example – Blind Sink Support
      2. 5.2.2 FSP Policy Example – Blind Sink Support with Max Power
    3. 5.3 Hybrid Mode Example
  9. 6References
  10. 7Revision History

5.3 Hybrid Mode Example

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.

Table 5-10 SPM Engine Parameters - Hybrid Mode Example
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
(1) The Total USB VBUS Power is 54 W; less than the sum of Port A Max Power and Port B Max Power. This is how Hybrid Mode is enabled from the GUI.
(2) Hybrid Mode is enabled with the Assured Capacity Policy selected in the GUI configurations.
Table 5-11 Hybrid Mode Parameters
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.

Table 5-12 Hybrid Mode Example
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
(1) Power distribution updates after roughly 8.5 seconds when the TPS257xx-Q1 firmware identifies a non-PD Sink.

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.

GUID-20231017-SS0I-ZP1K-FWPW-Z5S0CKCXZP65-low.png Figure 5-11 Hybrid Mode Negotiation Flow - Scenario 1
GUID-20231017-SS0I-WSCX-FP2N-Q0Q8BHTQ4FX9-low.png Figure 5-12 Hybrid Mode Negotiation Flow - Scenario 2
GUID-20231031-SS0I-S6L1-PG68-LRHTWM6WMFNS-low.png Figure 5-13 Hybrid Mode Negotiation Flow - Scenario 3