SPMU380 July   2026 TPS25730A

 

  1.   1
  2. 1Read This First
    1. 1.1 About This Manual
    2. 1.2 Notational Conventions
    3. 1.3 Glossary
    4. 1.4 Related Documents
    5. 1.5 Support Resources
    6. 1.6 Trademarks
  3. 2Introduction
    1. 2.1 Purpose and Scope
    2. 2.2 PD Controller Host Interface Description
      1. 2.2.1 Overview
    3. 2.3 Unique Address Interface
      1. 2.3.1 Unique Address Interface Protocol
  4. 3PD Controller Policy Modes
    1. 3.1 Overview
    2. 3.2 Sink Policy Mode
  5. 4Register Overview
    1. 4.1 TPS25730A Registers
  6. 54CC Task Detailed Descriptions
    1. 5.1 Overview
    2. 5.2 PD Message Tasks
      1. 5.2.1 'GSrC' - PD Get Source Capabilities
      2. 5.2.2 'GPPI' - PD Get Port Partner Information
      3. 5.2.3 'MBRd' - Message Buffer Read
    3. 5.3 System Tasks
      1. 5.3.1 'ANeg' - Auto Negotiate Sink Update
      2. 5.3.2 'DBfg' - Clear Dead Battery Flag
  7. 6User Reference
    1. 6.1 AUTO_NEGOTIATE_SINK Register
      1. 6.1.1 AUTO_NEGOTIATE_SINK Usage Example 1
      2. 6.1.2 AUTO_NEGOTIATE_SINK Usage Example 2
      3. 6.1.3 AUTO_NEGOTIATE_SINK Usage Example 3
      4. 6.1.4 AUTO_NEGOTIATE_SINK Usage Example 4
  8. 7Revision History

6.1.2 AUTO_NEGOTIATE_SINK Usage Example 2

When attached to a 36W source the PD controller has RX_SOURCE_CAPS:

  • PDO1: 5V at 3A
  • PDO2: 9V at 3A
  • PDO3: 15V at 2.4A

The PD controller has TX_SINK_CAPS set as:

  • PDO1: 5V at 0.1A (fixed)
  • PDO2: 20V at 3A (fixed)

The PD controller has AUTO_NEGOTIATE_SINK set as:

  • AUTO_NEGOTIATE_SINK = 0
  • AUTO_NEGOTIATE_SINK.AutoComputeSinkMinPower = 1
  • AUTO_NEGOTIATE_SINK.AutoComputeSinkMinVoltage = 0
  • AUTO_NEGOTIATE_SINK.ANMinVoltage = 20V
  • AUTO_NEGOTIATE_SINK.AutoComputeSinkMaxVoltage = 1
  • AUTO_NEGOTIATE_SINK.NoCapabilityMismatch = x (see table below)
  • AUTO_NEGOTIATE_SINK.ANRDOPriority = 0

The settings give the results in the table below. Note that ANMaxVoltage computed as 20V, but it does not affect the result. Because the ANMinVoltage was set to 20V, and the source is not offering 20V none of the source PDOs fulfill the sink requirements. Even though ANSinkCapMismatchPower=0 in this example, because the voltages offered are insufficient, the capability mismatch bit can still be set.

Table 6-2 AUTO_NEGOTIATE_SINK Usage Example 2
AUTO_NEGOTIATE_SINKACTIVE_CONTRACT_RDO
NoCapabilityMismatchOperatingXMinMaxOperatingXObjectPositionCapability Mismatch
03.0A3.0A11
13.0A3.0A10