SLVSHP8 January   2026 TPS544B28

ADVANCE INFORMATION  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Options
  6. 5 Pin Configuration and Functions
  7. 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 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  D-CAP4 Control
      2. 7.3.2  Internal VCC LDO and Using External Bias On the VCC Pin
        1. 7.3.2.1 Powering the Device From a Single Bus
        2. 7.3.2.2 Powering the Device From a Split-Rail Configuration
      3. 7.3.3  Multifunction Select (MS1) Pin
      4. 7.3.4  Multifunction Select (MS2) Pin
      5. 7.3.5  Address (ADR) Pin
      6. 7.3.6  Enable
      7. 7.3.7  Soft Start
      8. 7.3.8  Power Good
      9. 7.3.9  Overvoltage and Undervoltage Protection
      10. 7.3.10 Output Voltage Setting (External Feedback Configuration)
      11. 7.3.11 Remote Sense
      12. 7.3.12 Low-side MOSFET Zero-Crossing
      13. 7.3.13 Current Sense and Positive Overcurrent Protection
      14. 7.3.14 Low-side MOSFET Negative Current Limit
      15. 7.3.15 Output Voltage Discharge
      16. 7.3.16 UVLO Protection
      17. 7.3.17 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Auto-Skip (PFM) Eco-mode Light Load Operation
      2. 7.4.2 Forced Continuous-Conduction Mode
  9. 8 Programming Registers
    1. 8.1  OPERATION (Address = 1h) [Reset = 00h]
    2. 8.2  ON_OFF_CONFIG (Address = 2h) [Reset = XXh]
    3. 8.3  CLEAR_FAULTS (Address = 3h) [Reset = 00h]
    4. 8.4  WRITE_PROTECT (Address = 10h) [Reset = 00h]
    5. 8.5  STORE_USER_ALL (Address = 15h) [Reset = 00h]
    6. 8.6  RESTORE_USER_ALL (Address = 16h) [Reset = 00h]
    7. 8.7  CAPABILITY (Address = 19h) [Reset = C0h]
    8. 8.8  VOUT_MODE (Address = 20h) [Reset = 96h]
    9. 8.9  VOUT_COMMAND (Address = 21h) [Reset = 0000h]
    10. 8.10 VOUT_MARGIN_HIGH (Address = 25h) [Reset = 0000h]
    11. 8.11 VOUT_MARGIN_LOW (Address = 26h) [Reset = 0000h]
    12. 8.12 VOUT_TRANSITION_RATE (Address = 27h) [Reset = E81Ah]
    13. 8.13 VOUT_SCALE_LOOP (Address = 29h) [Reset = E804h]
    14. 8.14 FREQUENCY_SWITCH (Address = 33h) [Reset = 380Xh]
    15. 8.15 VOUT_OV_FAULT_RESPONSE (Address = 41h) [Reset = XXh]
    16. 8.16 VOUT_UV_FAULT_RESPONSE (Address = 45h) [Reset = XXh]
    17. 8.17 IOUT_OC_FAULT_LIMIT (Address = 46h) [Reset = 00XXh]
    18. 8.18 TON_DELAY (Address = 60h) [Reset = 000Xh]
    19. 8.19 TON_RISE (Address = 61h) [Reset = F80Xh]
    20. 8.20 TOFF_DELAY (Address = 64h) [Reset = 000Xh]
    21. 8.21 TOFF_FALL (Address = 65h) [Reset = F80Xh]
    22. 8.22 STATUS_BYTE (Address = 78h) [Reset = 81h]
    23. 8.23 STATUS_WORD (Address = 79h) [Reset = 2800h]
    24. 8.24 STATUS_CML (Address = 7Eh) [Reset = 00h]
    25. 8.25 STATUS_MFR_SPECIFIC (Address = 80h) [Reset = 00h]
    26. 8.26 READ_VOUT (Address = 8Bh) [Reset = 0000h]
    27. 8.27 READ_IOUT (Address = 8Ch) [Reset = DXXXh]
    28. 8.28 READ_TEMP1 (Address = 8Dh) [Reset = 0XXXh]
    29. 8.29 PMBUS_REVISION (Address = 98h) [Reset = 55h]
    30. 8.30 MFR_ID (Address = 99h) [Reset = 4954h]
    31. 8.31 MFR_MODEL (Address = 9Ah) [Reset = 00284B54h]
    32. 8.32 MFR_REVISION (Address = 9Bh) [Reset = X0h]
    33. 8.33 IC_DEVICE_ID (Address = ADh) [Reset = 00284B544954h]
    34. 8.34 IC_DEVICE_REV (Address = AEh) [Reset = 00h]
    35. 8.35 SYS_CFG_USER1 (Address = D1h) [Reset = XXh]
    36. 8.36 PASSKEY (Address = D2h) [Reset = X0h]
    37. 8.37 COMP (Address = D4h) [Reset = XXh]
    38. 8.38 VBOOT (Address = D5h) [Reset = XXh]
    39. 8.39 NVM_CHECKSUM (Address = D9h) [Reset = 0000h]
    40. 8.40 FUSION_ID0 (Address = FCh) [Reset = 02C0h]
    41. 8.41 FUSION_ID1 (Address = FDh) [Reset = 4h]
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Output Voltage Setting Point
        2. 9.2.2.2 Choose the Switching Frequency
        3. 9.2.2.3 Choose the Inductor
        4. 9.2.2.4 Choose the Output Capacitor
        5. 9.2.2.5 Choose the Input Capacitors (CIN)
        6. 9.2.2.6 VCC Bypass Capacitor
        7. 9.2.2.7 BOOT Capacitor
        8. 9.2.2.8 PG Pullup Resistor
        9. 9.2.2.9 Choose the PMBus® Address and Fault Recovery Mode
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information
    1. 12.1 Tape and Reel Information

7.4.1 Auto-Skip (PFM) Eco-mode Light Load Operation

If Skip (PFM)-mode is selected through the PMBus interface, the device automatically reduces the switching frequency at light-load conditions to maintain high efficiency. See the Programming Registers section on how to select the PFM mode.

As the output current decreases from heavy load condition, the inductor current also decreases until the valley of the inductor ripple current touches the zero-crossing threshold (Low-side MOSFET Zero-Crossing). The zero-crossing threshold sets the boundary between the continuous-conduction and discontinuous-conduction modes. The synchronous MOSFET turns off when this zero-crossing threshold is detected. As the load current decreases further, the converter runs into discontinuous-conduction mode (DCM). The on-time is maintained to a level approximately the same as during continuous-conduction mode operation so that discharging the output capacitor with a smaller load current to the level of the reference voltage requires more time. Use Equation 4 to calculate the transition point to light-load operation IOUT(LL) (for example: the boundary between continuous- and discontinuous-conduction mode).

For low output ripple, TI recommends using only ceramic output capacitors for designs that operate in skip-mode.

Equation 4. IOUT(LL)=12×VIN-VO×VOVIN×1L×fSW