SNVSAU8A June   2017  – February 2024 TPS549B22

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 25-A FET
      2. 6.3.2 On-Resistance
      3. 6.3.3 Package Size, Efficiency and Thermal Performance
      4. 6.3.4 Soft-Start Operation
      5. 6.3.5 VDD Supply Undervoltage Lockout (UVLO) Protection
      6. 6.3.6 EN_UVLO Pin Functionality
      7. 6.3.7 Fault Protections
        1. 6.3.7.1 Current Limit (ILIM) Functionality
        2. 6.3.7.2 VDD Undervoltage Lockout (UVLO)
        3. 6.3.7.3 Overvoltage Protection (OVP) and Undervoltage Protection (UVP)
        4. 6.3.7.4 Out-of-Bounds Operation
        5. 6.3.7.5 Overtemperature Protection
    4. 6.4 Device Functional Modes
      1. 6.4.1 D-CAP3™ Control Mode Topology
      2. 6.4.2 DCAP Control Topology
    5. 6.5 Programming
      1. 6.5.1 Programmable Pin-Strap Settings
        1. 6.5.1.1 Address Selection (ADDR) Pin
        2. 6.5.1.2 VSEL Pin
        3. 6.5.1.3 D-CAP3™ Control Mode Selection
        4. 6.5.1.4 Application Workaround to Support 4-ms and 8-ms SS Settings
      2. 6.5.2 Programmable Analog Configurations
        1. 6.5.2.1 RSP/RSN Remote Sensing Functionality
          1. 6.5.2.1.1 Output Differential Remote Sensing Amplifier
        2. 6.5.2.2 Power Good (PGOOD Pin) Functionality
      3. 6.5.3 PMBus Programming
        1. 6.5.3.1 TPS549B22 Limitations to the PMBUS Specifications
        2. 6.5.3.2 Target Address Assignment
        3. 6.5.3.3 PMBUS Address Selection
        4. 6.5.3.4 Supported Formats
          1. 6.5.3.4.1 Direct Format — Write
          2. 6.5.3.4.2 Combined Format — Read
        5. 6.5.3.5 Stop Separated Reads
        6. 6.5.3.6 Supported PMBUS Commands and Registers
  8. 7 Register Maps
    1. 7.1  OPERATION Register (address = 1h)
    2. 7.2  ON_OFF_CONFIG Register (address = 2h)
    3. 7.3  CLEAR FAULTS (address = 3h)
    4. 7.4  WRITE PROTECT (address = 10h)
    5. 7.5  STORE_DEFAULT_ALL (address = 11h)
    6. 7.6  RESTORE_DEFAULT_ALL (address = 12h)
    7. 7.7  CAPABILITY (address = 19h)
    8. 7.8  VOUT_MODE (address = 20h)
    9. 7.9  VOUT_COMMAND (address = 21h)
    10. 7.10 VOUT_MARGIN_HIGH (address = 25h) ®
    11. 7.11 VOUT_MARGIN_LOW (address = 26h)
    12. 7.12 STATUS_BYTE (address = 78h)
    13. 7.13 STATUS_WORD (High Byte) (address = 79h)
    14. 7.14 STATUS_VOUT (address = 7Ah)
    15. 7.15 STATUS_IOUT (address = 7Bh)
    16. 7.16 STATUS_CML (address = 7Eh)
    17. 7.17 MFR_SPECIFIC_00 (address = D0h)
    18. 7.18 MFR_SPECIFIC_01 (address = D1h)
    19. 7.19 MFR_SPECIFIC_02 (address = D2h)
    20. 7.20 MFR_SPECIFIC_03 (address = D3h)
    21. 7.21 MFR_SPECIFIC_04 (address = D4h)
    22. 7.22 MFR_SPECIFIC_06 (address = D6h)
    23. 7.23 MFR_SPECIFIC_07 (address = D7h)
    24. 7.24 MFR_SPECIFIC_44 (address = FCh)
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 TPS549B22 1.5-V to 18-V Input, 1-V Output, 25-A Converter
      2. 8.2.2 Design Requirements
      3. 8.2.3 Detailed Design Procedure
        1. 8.2.3.1  Custom Design With WEBENCH® Tools
        2. 8.2.3.2  Switching Frequency Selection
        3. 8.2.3.3  Inductor Selection
        4. 8.2.3.4  Output Capacitor Selection
          1. 8.2.3.4.1 Minimum Output Capacitance to Make Sure of Stability
          2. 8.2.3.4.2 Response to a Load Transient
          3. 8.2.3.4.3 Output Voltage Ripple
        5. 8.2.3.5  Input Capacitor Selection
        6. 8.2.3.6  Bootstrap Capacitor Selection
        7. 8.2.3.7  BP Pin
        8. 8.2.3.8  R-C Snubber and VIN Pin High-Frequency Bypass
        9. 8.2.3.9  Optimize Reference Voltage (VSEL)
        10. 8.2.3.10 MODE Pin Selection
        11. 8.2.3.11 ADDR Pin Selection
        12. 8.2.3.12 Overcurrent Limit Design
      4. 8.2.4 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Examples
      3. 8.4.3 Mounting and Thermal Profile Recommendation
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Development Support
        1. 9.1.1.1 Custom Design With WEBENCH® Tools
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RVF|40
Thermal pad, mechanical data (Package|Pins)
Orderable Information
8.2.3.4.3 Output Voltage Ripple

The output voltage ripple is another important design consideration. Equation 10 calculates the minimum output capacitance required to meet the output voltage ripple specification. This criterion is the requirement when the impedance of the output capacitance is dominated by ESR.

Equation 10. GUID-D4EB1C8F-8B3C-4285-8FDB-284614BAE5D5-low.gif

In this case, the maximum output voltage ripple is 10 mV. For this requirement, the minimum capacitance for ripple requirement yields 82 µF. Because this capacitance value is significantly lower compared to that of transient requirement, determine the capacitance bank from steps in the previous section Section 8.2.3.4.2. Because the output capacitor bank consists of both POSCAP and MLCC type capacitors, it is important to consider the ripple effect at the switching frequency due to effective ESR. Use Equation 11 to determine the maximum ESR of the output capacitor bank for the switching frequency.

Equation 11. GUID-A551984E-301B-46A8-B0FB-E93623F61577-low.gif

Estimate the effective ESR at the switching frequency by obtaining the impedance vs frequency characteristics of the output capacitors. The parallel impedance of capacitor bank 1 and capacitor bank 2 at the switching frequency of the design example is estimated to be 1.2 mΩ, which is less than that of the maximum ESR value. Therefore, the output voltage ripple requirement (10 mV) can be met. For detailed calculation on the effective ESR please contact the factory to obtain a user-friendly Excel based design tool.