SLVSDD7A September   2016  – February 2019 UCD9090A


  1. Features
  2. Applications
  3. Description
    1.     Typical Application Schematic
  4. Revision History
  5. Pin Configuration and Functions
    1.     Pin Functions
  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. 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. Turn-On Sequencing
        2. Turn-Off Sequencing
        3. Sequencing Configuration Options
      2. 7.4.2  Pin-Selected Rail States
      3. 7.4.3  Monitoring
        1. Voltage Monitoring
        2. Current Monitoring
        3. Remote Temperature Monitoring and Internal Temperature Sensor
        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
        1. GPO Delays
        2. State Machine Mode Enable
      9. 7.4.9  GPI Special Functions
        1. Fault Shutdown Rails
        2. Configured as Sequencing Debug Pin
        3. Configured as Fault Pin
        4. Cold Boot Mode Enable
      10. 7.4.10 Power Supply Enables
      11. 7.4.11 Cascading Multiple Devices
      12. 7.4.12 PWM Outputs
        1. FPWM1-8
        2. PWM1-2
      13. 7.4.13 Programmable Multiphase PWMs
      14. 7.4.14 Margining
        1. Open-Loop Margining
        2. Closed-Loop Margining
      15. 7.4.15 Run Time Clock
      16. 7.4.16 System Reset Signal
      17. 7.4.17 Watch Dog Timer
      18. 7.4.18 Data and Error Logging to Flash Memory
      19. 7.4.19 Brownout Function
      20. 7.4.20 PMBus Address Selection
      21. 7.4.21 Device Reset
      22. 7.4.22 JTAG Interface
      23. 7.4.23 Internal Fault Management and Memory Error Correction (ECC)
    5. 7.5 Programming
      1. 7.5.1 Full Configuration Update While in Normal Mode
  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. Estimating ADC Reporting Accuracy
      3. 8.2.3 Application Curves
  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 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RGZ|48
Thermal pad, mechanical data (Package|Pins)
Orderable Information

Shut Down All Rails and Sequence On (Resequence)

In response to a fault, or a RESEQUENCE command, the UCD9090A can be configured to turn off a set of rails and then sequence them back on. To sequence all rails in the system, then all rails must be selected as fault-shutdown slaves of the faulted rail. The rails designated as fault-shutdown slaves will do soft shutdowns regardless of whether the faulted rail is set to stop immediately or stop with delay. Shut-down-all-rails and sequence-on are not performed until retries are exhausted for a given fault.

While waiting for the rails to turn off, an error is reported if any of the rails reaches its TOFF_MAX_WARN_LIMIT. There is a configurable option to continue with the resequencing operation if this occurs. After the faulted rail and fault-shutdown slaves sequence-off, the UCD9090A waits for a programmable delay time between 0 and 1275 ms in increments of 5 ms and then sequences-on the faulted rail and fault-shutdown slaves according to the start-up sequence configuration. This is repeated until the faulted rail and fault-shutdown slaves successfully achieve regulation or for a user-selected 1, 2, 3, 4 or unlimited times. If the resequence operation is successful, the resequence counter is reset if all of the rails that were resequenced maintain normal operation for one second.

Once shut-down-all-rails and sequence-on begin, any faults on the fault-shutdown slave rails are ignored. If there are two or more simultaneous faults with different fault-shutdown slaves, the more conservative action is taken. For example, if a set of rails is already on its second resequence and the device is configured to resequence three times, and another set of rails enters the resequence state, that second set of rails is only resequenced once. Another example – if one set of rails is waiting for all of its rails to shut down so that it can resequence, and another set of rails enters the resequence state, the device now waits for all rails from both sets to shut down before resequencing.

If any rails at resequence state are caused by a GPI fault response, the whole resequence is suspended until the GPI fault is clear.