ZHCSD04E November   2014  – March 2022 TPS65400

PRODUCTION DATA  

  1. 1 特性
  2. 2 应用
  3. 3 说明
  4. 4 Revision History
  5. 5 说明（续）
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 System Characteristics
    7. 7.7 Operational Parameters
    8. 7.8 Package Dissipation Ratings
    9. 7.9 Typical Characteristics: System Efficiency
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagrams
    3. 8.3 Feature Description
      1. 8.3.1  Startup Timing and Power Sequencing
        1. 8.3.1.1 Startup Timing
        2. 8.3.1.2 External Sequencing
        3. 8.3.1.3 Internal Sequencing
      2. 8.3.2  UVLO and Precision Enables
      3. 8.3.3  Soft-Start and Prebiased Startup
        1. 8.3.3.1 Analog Soft-Start (Default) and Digital Soft-Start
        2. 8.3.3.2 Soft-Start Capacitor Selection
      4. 8.3.4  PWM Switching Frequency Selection
      5. 8.3.5  Clock Synchronization
      6. 8.3.6  Phase Interleaving
      7. 8.3.7  Fault Handling
      8. 8.3.8  OCP for SW1 to SW4
      9. 8.3.9  Overcurrent Protection for SW1 to SW4 in Current Sharing Operation
      10. 8.3.10 Recovery on Power Loss
      11. 8.3.11 Feedback Compensation
      12. 8.3.12 Adjusting Output Voltage
      13. 8.3.13 Digital Interface – PMBus
      14. 8.3.14 Initial Configuration
    4. 8.4 Device Functional Modes
      1. 8.4.1 CCM Operation Mode
      2. 8.4.2 CCM/DCM Operation Mode
      3. 8.4.3 Current Sharing Mode
    5. 8.5 Programming
      1. 8.5.1 PMBus
        1. 8.5.1.1 Overview
        2. 8.5.1.2 PMBus Protocol
          1. 8.5.1.2.1  PMBus Protocol
          2. 8.5.1.2.2  Transactions (No PEC)
          3. 8.5.1.2.3  Addressing
          4. 8.5.1.2.4  Startup
          5. 8.5.1.2.5  Bus Speed
          6. 8.5.1.2.6  I2CALERT Terminal
          7. 8.5.1.2.7  CONTROL Terminal
          8. 8.5.1.2.8  Packet Error Checking
          9. 8.5.1.2.9  Group Commands
          10. 8.5.1.2.10 Unsupported Features
      2. 8.5.2 PMBus Register Descriptions
        1. 8.5.2.1 Overview
        2. 8.5.2.2 Memory Model
        3. 8.5.2.3 Data Formats
        4. 8.5.2.4 Fault Monitoring
    6. 8.6 Register Maps
      1. 8.6.1 PMBus Core Commands
        1. 8.6.1.1  (00h) PAGE
        2. 8.6.1.2  (01h) OPERATION
        3. 8.6.1.3  (03h) CLEAR_FAULTS
        4. 8.6.1.4  (10h) WRITE_PROTECT
        5. 8.6.1.5  (11h) STORE_DEFAULT_ALL
        6. 8.6.1.6  (19h) CAPABILITY
        7. 8.6.1.7  (78h) STATUS_BYTE
        8. 8.6.1.8  (79h) STATUS_WORD
        9. 8.6.1.9  (7Ah) STATUS_VOUT
        10. 8.6.1.10 (80h) STATUS_MFR_SPECIFIC
        11. 8.6.1.11 (98h) PMBUS_REVISION
        12. 8.6.1.12 (ADh) IC_DEVICE_ID
        13. 8.6.1.13 (AEh) IC_DEVICE_REV
      2. 8.6.2 Manufacturer-Specific Commands
        1. 8.6.2.1  (D0h) USER_DATA_BYTE_00
        2. 8.6.2.2  (D1h) USER_DATA_BYTE_01
        3. 8.6.2.3  (D2h) PIN_CONFIG_00
        4. 8.6.2.4  (D3h) PIN_CONFIG_01
        5. 8.6.2.5  (D4h) SEQUENCE_CONFIG
        6. 8.6.2.6  (D5h) SEQUENCE_ORDER
        7. 8.6.2.7  (D6h) IOUT_MODE
        8. 8.6.2.8  (D7h) FREQUENCY_PHASE
        9. 8.6.2.9  (D8h) VREF_COMMAND
        10. 8.6.2.10 (D9h) IOUT_MAX
        11. 8.6.2.11 (DAh) USER_RAM_00
        12. 8.6.2.12 (DBh) SOFT_RESET
        13. 8.6.2.13 (DCh) RESET_DELAY
        14. 8.6.2.14 (DDh) TON_TOFF_DELAY
        15. 8.6.2.15 (DEh) TON_TRANSITION_RATE
        16. 8.6.2.16 (DFh) VREF_TRANSITION_RATE
        17. 8.6.2.17 (F0h) SLOPE_COMPENSATION
        18. 8.6.2.18 (F1h) ISENSE_GAIN
        19. 8.6.2.19 (FCh) DEVICE_CODE
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Internal Operation Typical Application
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Component Selection
            1. 9.2.1.2.1.1 Output Inductor Selection
            2. 9.2.1.2.1.2 Output Capacitor Selection
          2. 9.2.1.2.2 Internal Operation With Some Switchers Disabled
          3. 9.2.1.2.3 Internal Operation With All Switchers Enabled
          4. 9.2.1.2.4 Example Configuration
          5. 9.2.1.2.5 Unused Switchers
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Current Sharing Typical Application
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
          1. 9.2.2.2.1 Current Sharing Timing Example
      3. 9.2.3 External Sequencing Application
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
          1. 9.2.3.2.1 External Sequencing Through PG Pins
          2. 9.2.3.2.2 External Sequencing Through SW
          3. 9.2.3.2.3 Example Configuration
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
      2. 12.1.2 Related Parts
    2. 12.2 接收文档更新通知
    3. 12.3 术语表
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 术语表
  13. 13Mechanical, Packaging, and Orderable Information

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

8.3.7 Fault Handling

OVP, OCP, and undervoltage protection (UVP) are handled for each switcher independently. OVP or OCP faults that occur on one switcher do not affect the other outputs. There are two exceptions:

  • If current-sharing mode (ISHARE) is detected for a switcher that faults, both switchers in parallel have the same response to OVP or OCP.
  • When using internal sequencing, in the case of faults occurring during the initial power-up sequence, all switchers are disabled for 500 ms, after which, the startup sequence is restarted.

During the soft-start time for a switcher, all fault signals (OVP, OCP, and UVP) are disabled and reset to the unfaulted condition. The first moment when faults can be triggered is after the end of the soft-start sequence.

OVP thresholds are set as a percentage of VREF. A deglitching time of 50 μs is used for the overvoltage. When an overvoltage occurs at the OVP upper threshold limit, the high-side FET and the low-side FET are disabled for that switcher until the OVP falling threshold is reached. When the OVP falling threshold is reached, the low-side FET turns on for 200 ns to ensure that the bootstrap capacitor is recharged before resuming normal operation of the converter.

Output voltage falling below the UVP thresholds causes the corresponding PGOOD output to fall, but the switcher continues to operate as it tries to increase the output voltage. However, if the PGOOD terminal is tied to the enable ENSWx signal of another switcher on the PCB (for external sequencing), the output for that ENSWx-PGOOD-tied switcher is disabled until output voltage is nominal and PGOOD is good.

OTP shuts down all switchers. When the temperature drops below the hysteresis level, a soft reset is triggered and the chip restarts from the startup sequence.

Section 8.5.2.4 describes fault reporting and clearing of fault status registers.

The OVP and UVP sensing is deglitched to prevent unwanted tripping. The faults need to be sustained for more than 55 μs typically (60 μs max) to be registered and trigger protection circuits and PGOOD output to fall. Fault detection is disabled on a given switcher when its VREF is being ramped (as result of an I2C command to change VREF). An additional 100-μs fault blanking time results after VREF has been adjusted to its target level.