SLVSA30D April   2011  – March  2019 UCD9090

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Typical 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 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 User Interface (UI)
      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
        1. 7.4.8.1 GPO Delays
        2. 7.4.8.2 State Machine Mode Enable
      9. 7.4.9  GPI Special Functions
      10. 7.4.10 Power-Supply Enable Pins
      11. 7.4.11 Cascading Multiple Devices
        1. 7.4.11.1 Connecting the GPIO Pin to a PMBus_CNTRL Pin
        2. 7.4.11.2 Connecting the GPIO Pin to a MON Pin
      12. 7.4.12 PWM Outputs
        1. 7.4.12.1 FPWM1-8
        2. 7.4.12.2 PWM1-2
      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 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. 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 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

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

7.4.3.2 Current Monitoring

Current can be monitored using the analog inputs. External circuitry, see Figure 13, must be used in order to convert the current to a voltage within the range of the UCD9090 MONx input being used.

If a monitor input is configured as a current, the measurements are smoothed by a sliding-average digital filter. The current for 1 rail is measured every 200μs. If the device is programmed to support 10 rails (independent of current not being monitored at all rails), then each rail's current will get measured every 2ms. The current calculation is done with a sliding average using the last 4 measurements. The filter reduces the probability of false fault detections, and introduces a small delay to the current reading. If a rail is defined with a voltage monitor and a current monitor, then monitoring for undercurrent warnings begins once the rail voltage reaches POWER_GOOD_ON. If the rail does not have a voltage monitor, then current monitoring begins after TON_DELAY.

The device supports multiple PMBus commands related to current, including READ_IOUT, which reads external currents from the MON pins; IOUT_OC_FAULT_LIMIT, which sets the overcurrent fault limit; IOUT_OC_WARN_LIMIT, which sets the overcurrent warning limit; and IOUT_UC_FAULT_LIMIT, which sets the undercurrent fault limit. The UCD90xxx Sequencer and System Health Controller PMBus Command Reference contains a detailed description of how current fault responses are implemented using PMBus commands.

IOUT_CAL_GAIN is a PMBus command that allows the scale factor of an external current sensor and any amplifiers or attenuators between the current sensor and the MON pin to be entered by the user in milliohms. IOUT_CAL_OFFSET is the current that results in 0 V at the MON pin. The combination of these PMBus commands allows current to be reported in amperes. The example below using the INA196 would require programming IOUT_CAL_GAIN to Rsense(mΩ)×20.

UCD9090 curr_mon_lvsa30.gifFigure 13. Current Monitoring Circuit Example Using the INA196