SLVAFG6B December   2022  – November 2024 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 On/Off Transition Management
      1. 4.2.1 Engine On/Off 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

4.2.1 Engine On/Off Power Foldback Operation Example

The example below depicts the Power Foldback operation upon detection of VIN voltage level changes. Table 5-10 shows the configurable SPM Engine parameters used in this section's example.

Table 4-6 SPM Engine Parameters - Engine On/Off Power Foldback Example
SPM Engine Parameters Configuration Description
System Max Power (RANGE 4) 75W Total system power capacity that is allocated for Port A and Port B
Port A Max Power 60W Maximum Port A Power
Port B Max Power 60W Maximum Port B Power
Port A Min Power 15W Minimum Port A power
Port B Min Power 15W Minimum Port B power
RANGE 3 60W Total VBUS Power allocated for Port A and B when VIN < RANGE 3 to 4 Threshold
RANGE 2 30W Total VBUS Power allocated for Port A and B when VIN < RANGE 2 to 3 Threshold
Sharing Mode Fair Share Power Policy Port Min Power is guaranteed for each port and remaining power is intelligently distributed
Table 4-7 Engine On/Off Power Foldback Operation Example
Port A Port B
Scenario 1: Port A connects in Normal Operation in RANGE 4 (VIN > RANGE 3 to 4 Threshold)
Power Required by Sink 60W
Power Distributed to Sink 60W
Scenario 2: Port B connects in Normal Operation in RANGE 4 (VIN>RANGE 3 to 4 Threshold)
Power Required by Sinks 60W 60W
Power Distributed to Sinks 37.5W 37.5W
Scenario 3: Start of Power Foldback Operation
VIN < RANGE 4 to 3 Threshold w/ reduced power = 60W 37.5W 37.5W
After Falling VIN Deglitch time, 30W Source Capabilities resent to Port A and Port B 37.5W 37.5W
Sink accepts 30W 30W
Scenario 4: Power Foldback Operation (continued)
VIN < RANGE 3 to 2 Threshold w/ reduced power = 30W 30W 30W
After Falling VIN Deglitch time, 15W Source Capabilities resent to Port A and Port B 30W 30W
Sink accepts and Power Off (Grace Period) starts 15W 15W
VIN remains < RANGE 3 to 2 Threshold 15W 15W
Ports disable after Power Off (Grace Period) expires 0W 0 W
VIN transitions to > RANGE 3 to 4 Threshold 0W 0 W
After Rising VIN Deglitch time, 15W Source Capabilities is sent to both ports 15W 15W
Sink Accepts 15W 15W
Power Required by Sinks = 60W 15W 15W
37.5W Source Capabilities resent to Port A and Port B 15W 15W
Sink Accepts 37.5W 37.5W