SLVA275C january   2010  – may 2023 UCD9081

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
  4. 2Hardware
    1. 2.1 Package: RHB (S-PQFP-N32), 32-Pin Plastic Quad Flatpack
    2. 2.2 Hardware and Pinout
    3. 2.3 Detailed Pin Descriptions
      1. 2.3.1 RST
      2. 2.3.2 SDA
      3. 2.3.3 SCL
      4. 2.3.4 ADDRx
      5. 2.3.5 ROSC
  5. 3Software
    1. 3.1 Data File Format
    2. 3.2 I2C Transactions
    3. 3.3 Device Version
    4. 3.4 Checksum
    5. 3.5 Sample Configuration Data File
      1. 3.5.1 Factory Default
      2. 3.5.2 EVM Default Configuration
    6. 3.6 I2C Write and Read Transaction Formats
      1. 3.6.1 I2C Write Transaction
      2. 3.6.2 I2C Read Transaction
    7. 3.7 Pseudo I2C Write and Read Transactions
      1. 3.7.1 UCD9081 I2C Transactions for Writing User Data and PARAMS
      2. 3.7.2 UCD9081 I2C Transactions for Reading User Data and PARAMS
  6. 4User Configuration
    1. 4.1 Configuration Parameter Memory Map
    2. 4.2 Configuration Parameter Detail
      1. 4.2.1  GpDir
      2. 4.2.2  NegateEnablePolarity
      3. 4.2.3  SeqEventPending
      4. 4.2.4  SequenceEventParameters
      5. 4.2.5  SequenceEventLink
      6. 4.2.6  SequenceEventData
      7. 4.2.7  DependencyMasks
      8. 4.2.8  UnderVoltageThresholds
      9. 4.2.9  OverVoltageThresholds
      10. 4.2.10 RampTime
      11. 4.2.11 OutOfRegulationWidth
      12. 4.2.12 UnsequenceTime
      13. 4.2.13 EnablePolarity
      14. 4.2.14 SaveRailLog
      15. 4.2.15 ReferenceSelect
      16. 4.2.16 LastUnusedSeq
      17. 4.2.17 IgnoreGlitchAlarms
      18. 4.2.18 IgnoreFlashErrorLog
      19. 4.2.19 Checksum
  7. 5Additional Considerations
    1. 5.1 Embedded Application
    2. 5.2 Timing
      1. 5.2.1 UCD9081 Startup
      2. 5.2.2 Clock Stretching After Flash Erase
      3. 5.2.3 Bit Timeout
      4. 5.2.4 Byte or Transaction Timeout
  8. 6References
  9. 7Revision History

UnderVoltageThresholds

The UnderVoltageThresholds field in the configuration parameters specifies each rail undervoltage threshold that is used when monitoring this rail. The address map for these registers is as follows:

AddressSizeDefault ValueDescription
0xE11020x0000Undervoltage threshold for rail 8
0xE11220x0000Undervoltage threshold for rail 7
0xE11420x0000Undervoltage threshold for rail 6
0xE11620x0000Undervoltage threshold for rail 5
0xE11820x0000Undervoltage threshold for rail 4
0xE11A20x0000Undervoltage threshold for rail 3
0xE11C20x0000Undervoltage threshold for rail 2
0xE11E20x0000Undervoltage threshold for rail 1

The format for each register is as follows:

GUID-AE2D09B6-6BDC-4C58-BD00-7C2310E210BF-low.gif

The voltage conversion depends on the configured voltage reference, and the pullup/pulldown resistors used on the board for each rail. The voltage reference is selected as either 2.5 V (internal) or VCC (external). The formula to convert the desired rail UnderVoltageThreshold to Vraw follows:

Without external rail voltage divider:

Equation 1. GUID-A9B4FDE1-DD86-4E3F-BF0C-2E7D4465E678-low.gif

With external rail voltage divider:

Equation 2. GUID-5082E750-F0C5-4C1F-9AA4-7F43DF7B93D3-low.gif