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

7.4.20 PMBus Address Selection

Two pins are allocated to decode the PMBus address. At power up, the device applies a bias current to each address-detect pin, and the voltage on that pin is captured by the internal 12-bit ADC. The PMBus address is calculated as follows.

Equation 3. PMBus Address = 12 × bin(VAD01) + bin(VAD00)

where

  • bin(VAD0x) is the address bin for one of eight addresses as shown in Table 8

The address bins are defined by the MIN and MAX VOLTAGE RANGE (V). Each bin is a constant ratio of 1.25 from the previous bin. This method maintains the width of each bin relative to the tolerance of standard 1% resistors.

Table 8. PMBus Address Bins

ADDRESS BIN RPMBus
PMBus RESISTANCE (kΩ)
open —
11 200
10 154
9 118
8 90.9
7 69.8
6 53.6
5 41.2
4 31.6
short —

A low impedance (short) on either address pin that produces a voltage below the minimum voltage causes the PMBus address to default to address 126 (0x7E). A high impedance (open) on either address pin that produces a voltage above the maximum voltage also causes the PMBus address to default to address 126 (0x7E).

Address 0 is not used because it is the PMBus general-call address. Addresses 11 and 127 cannot be used by this device or any other device that shares the PMBus with it, because those are reserved for manufacturing programming and test. It is recommended that address 126 not be used for any devices on the PMBus, because this is the address that the UCD9090 defaults to if the address lines are shorted to ground or left open. Table 9 summarizes which PMBus addresses can be used. Other SMBus/PMBus addresses have been assigned for specific devices. For a system with other types of devices connected to the same PMBus, see the SMBus device address assignments table in Appendix C of the latest version of the System Management Bus (SMBus) specification. The SMBus specification can be downloaded at http://smbus.org/specs/smbus20.pdf.

Table 9. PMBus Address Assignment Rules

ADDRESS STATUS REASON
0 Prohibited SMBus generaladdress call
11 Avoid Causes conflicts with other devices during program flash updates.
12 Prohibited PMBus alert response protocol
126 For JTAG Use Default value; may cause conflicts with other devices.
127 Prohibited Used by TI manufacturing for device tests.
UCD9090 pmbus_addr_detect_slvsa30.gifFigure 29. PMBus Address-Detection Method

NOTE

Address 126 (0x7E) is not recommended to be selected as a permanent PMBus address for any given application design. Maintaining the address in default state as 126 (0x7E) enables the JTAG and disallows using the JTAG compatible pins (27-30) as GPIOs. The UCD9090 runs at 10% slower frequency while the JTAG is enabled to ensure best JTAG operation.