SLVSDD4C September   2016  – March 2020 UCD90160A

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Simplified Application
  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 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 Rail Configuration
      2. 7.3.2 TI Fusion GUI
      3. 7.3.3 PMBus Interface
    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  Voltage Monitoring
      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. 7.4.8.1 GPO Delays
        2. 7.4.8.2 State Machine Mode Enable
      9. 7.4.9  GPI Special Functions
        1. 7.4.9.1 Fault Shutdown Rails
        2. 7.4.9.2 Configured as Sequencing Debug Pin
        3. 7.4.9.3 Configured as Fault Pin
        4. 7.4.9.4 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. 7.4.12.1 FPWM1-8
        2. 7.4.12.2 PWM1-4
      13. 7.4.13 Programmable Multiphase PWMs
      14. 7.4.14 Margining
        1. 7.4.14.1 Open-Loop Margining
        2. 7.4.14.2 Closed-Loop Margining
      15. 7.4.15 System Reset Signal
      16. 7.4.16 Watch Dog Timer
      17. 7.4.17 Run Time Clock
      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
    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
      3. 8.2.3 Application Curves
      4. 8.2.4 Estimating ADC Reporting Accuracy
  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 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Community Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.4.16 Watch Dog Timer

A GPI and GPO can be configured as a watchdog timer (WDT). The WDT can be independent of power supply sequencing or tied to a GPIO functioning as a watchdog output (WDO) that is configured to provide a system-reset signal. The WDT can be reset by toggling a watchdog input (WDI) pin or by writing to SYSTEM_WATCHDOG_RESET over I2C. The WDI and WDO pins are optional when using the watchdog timer. The WDI can be replaced by SYSTEM_WATCHDOG_RESET command and the WDO can be manifested through the Boolean Logic defined GPOs or through the System Reset function.

The WDT can be active immediately at power up or set to wait while the system initializes. Table 10 lists the programmable wait times before the initial timeout sequence begins.

Table 10. WDT Initial Wait Time

WDT INITIAL WAIT TIME
0 ms
100 ms
200 ms
400 ms
800 ms
1.6 s
3.2 s
6.4 s
12.8 s
25.6 s
51.2 s
102 s
205 s
410 s
819 s
1638 s

The watchdog timeout is programmable from 0.001s to 32.256s. See the UCD90xxx Sequencer and System Health Controller PMBus Command Reference for details on configuring the watchdog timeout. If the WDT times out, the UCD90160A can assert a GPIO pin configured as WDO that is separate from a GPIO defined as system-reset pin, or it can generate a system-reset pulse. After a timeout, the WDT is restarted by toggling the WDI pin or by writing to SYSTEM_WATCHDOG_RESET over I2C.

UCD90160A watchdog_t_lvs966.gifFigure 27. Timing of GPIOs Configured for Watchdog Timer Operation