SLVSCQ9E November   2014  – March 2022 TPS65400

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  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 Receiving Notification of Documentation Updates
    3. 12.3 Glossary
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.5 Clock Synchronization

The RCLOCK_SYNC terminal can be used to synchronize the master clock switching frequency, FOSC, with an external clock source or another TPS65400. The external clock signal (which can come from another TPS65400 CLK_OUT terminal) should be AC coupled to the RCLOCK_SYNC terminal as shown in Figure 8-10. Choose the ROSC value so that the fixed frequency is nominally 30% lower than the external synchronizing clock frequency. An internal protection diode clamps the low level of the synchronizing signal to approximately –0.5 V. The internal clock synchronizes to the rising edge of the external clock.

GUID-6D1A8B60-2B12-4EF3-A4E8-64CBE3AF5DBF-low.gifFigure 8-10 AC-Coupled Clock Synchronization

TI recommends to choose an AC-coupling capacitance in the range of 50 to 100 pF. Exceeding the recommended capacitance may inject excessive energy through the internal clamping diode structure present on the RCLOCK_SYNC terminal. The typical trip level of the synchronization terminal is 1.5 V. To ensure proper synchronization and to avoid damaging the IC, the peak-to-peak value (amplitude) should be between 2.5 V and VDDA. The minimum duration of this pulse must be greater than 200 ns, and its maximum duration must be 200 ns less than the period of the switching cycle.

The external clock synchronization process begins after the TPS65400 is enabled and an external clock signal is detected. The frequency modulator adjusts the oscillator frequency to match the frequency of the pulses into the RCLOCK_SYNC terminal. It generally takes 50 cycles before the PWM frequency locks. If the external clock signal is removed after frequency synchronization, the master clock FOSC drifts to the frequency selected by ROSC.