SLVSAN9C April   2011  – March  2019 UCD90120A

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Simplified Schematic
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 I2C/SMBus/PMBus Timing Requirements
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 TI Fusion GUI
      2. 7.3.2 PMBus Interface
      3. 7.3.3 Rail Configuration
    4. 7.4 Device Functional Modes
      1. 7.4.1  Power-Supply Sequencing
        1. 7.4.1.1 Turn-On Sequencing
        2. 7.4.1.2 Turn-Off Sequencing
        3. 7.4.1.3 Sequencing Configuration Options
      2. 7.4.2  Pin-Selected Rail States
      3. 7.4.3  Monitoring
        1. 7.4.3.1 Voltage Monitoring
        2. 7.4.3.2 Current Monitoring
        3. 7.4.3.3 Remote Temperature Monitoring and Internal Temperature Sensor
        4. 7.4.3.4 Temperature by Host Input
      4. 7.4.4  Fault Responses and Alert Processing
      5. 7.4.5  Shut Down All Rails and Sequence On (Resequence)
      6. 7.4.6  GPIOs
      7. 7.4.7  GPO Control
      8. 7.4.8  GPO Dependencies
      9. 7.4.9  GPO Delays
      10. 7.4.10 State Machine Mode Enable
      11. 7.4.11 GPI Special Functions
      12. 7.4.12 Power-Supply Enables
      13. 7.4.13 Cascading Multiple Devices
      14. 7.4.14 PWM Outputs
        1. 7.4.14.1 FPWM1-8
        2. 7.4.14.2 PWM1-4
      15. 7.4.15 Programmable Multiphase PWMs
      16. 7.4.16 Margining
        1. 7.4.16.1 Open-Loop Margining
        2. 7.4.16.2 Closed-Loop Margining
      17. 7.4.17 System Reset Signal
      18. 7.4.18 Watch Dog Timer
      19. 7.4.19 Run Time Clock
      20. 7.4.20 Data and Error Logging to Flash Memory
      21. 7.4.21 Brownout Function
      22. 7.4.22 PMBus Address Selection
    5. 7.5 Programming
      1. 7.5.1 Device Configuration and Programming
        1. 7.5.1.1 Full Configuration Update While in Normal Mode
      2. 7.5.2 JTAG Interface
      3. 7.5.3 Internal Fault Management and Memory Error Correction (ECC)
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Estimating ADC Reporting Accuracy
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.4.13 Cascading Multiple Devices

A GPIO pin can be used to coordinate multiple controllers by using it as a power good-output from one device and connecting it to the PMBUS_CNTRL input pin of another. This imposes a master/slave relationship among multiple devices. During startup, the slave controllers initiate their start sequences after the master has completed its start sequence and all rails have reached regulation voltages. During shutdown, as soon as the master starts to sequence-off, it sends the shut-down signal to its slaves.

A shutdown on one or more of the master rails can initiate shutdowns of the slave devices. The master shutdowns can be initiated intentionally or by a fault condition. This method works to coordinate multiple controllers, but it does not enforce interdependency between rails within a single controller.

The PMBus specification implies that the power-good signal is active when ALL the rails in a controller are regulating at their programmed voltage. The UCD90120A allows GPIOs to be configured to respond to a desired subset of power-good signals.