SLVSHP9 July   2026 TPS544A28

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Related Products
  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  PMBus® Address (ADR) Pin
      6. 7.3.6  Output Voltage Setting
        1. 7.3.6.1 Setting VBOOT and VOUT_SCALE_LOOP
        2. 7.3.6.2 Setting Output Voltage (Internal Feedback)
        3. 7.3.6.3 Setting Output Voltage (External Feedback)
      7. 7.3.7  Switching Frequency
      8. 7.3.8  Dynamic Voltage Slew Rate
      9. 7.3.9  Enable
      10. 7.3.10 Soft Start and Soft Stop
      11. 7.3.11 Power Good
      12. 7.3.12 Overvoltage and Undervoltage Protection
      13. 7.3.13 Remote Sense
      14. 7.3.14 Low-side MOSFET Zero-Crossing
      15. 7.3.15 Current Sense and Positive Overcurrent Protection
      16. 7.3.16 Low-side MOSFET Negative Current Limit
      17. 7.3.17 Output Voltage Discharge
      18. 7.3.18 UVLO Protection
      19. 7.3.19 Telemetry
      20. 7.3.20 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 Register Map
      1. 8.1.1  OPERATION (Address = 01h)
      2. 8.1.2  ON_OFF_CONFIG (Address = 02h)
      3. 8.1.3  CLEAR_FAULTS (Address = 03h)
      4. 8.1.4  WRITE_PROTECT (Address = 10h)
      5. 8.1.5  STORE_USER_ALL (Address = 15h)
      6. 8.1.6  RESTORE_USER_ALL (Address = 16h)
      7. 8.1.7  CAPABILITY (Address = 19h)
      8. 8.1.8  VOUT_MODE (Address = 20h)
      9. 8.1.9  VOUT_COMMAND (Address = 21h)
      10.      57
      11. 8.1.10 VOUT_MARGIN_HIGH (Address = 25h)
      12. 8.1.11 VOUT_MARGIN_LOW (Address = 26h)
      13. 8.1.12 VOUT_TRANSITION_RATE (Address = 27h)
      14. 8.1.13 61
      15. 8.1.14 VOUT_SCALE_LOOP (Address = 29h)
      16. 8.1.15 FREQUENCY_SWITCH (Address = 33h)
      17. 8.1.16 64
      18. 8.1.17 VOUT_OV_FAULT_RESPONSE (Address = 41h)
      19. 8.1.18 VOUT_UV_FAULT_RESPONSE (Address = 45h)
      20. 8.1.19 IOUT_OC_FAULT_LIMIT (Address = 46h)
      21.      68
      22. 8.1.20 TON_DELAY (Address = 60h)
      23. 8.1.21 TON_RISE (Address = 61h)
      24.      71
      25. 8.1.22 TOFF_DELAY (Address = 64h)
      26. 8.1.23 TOFF_FALL (Address = 65h)
      27. 8.1.24 STATUS_BYTE (Address = 78h)
      28. 8.1.25 STATUS_WORD (Address = 79h)
      29. 8.1.26 STATUS_CML (Address = 7Eh)
      30. 8.1.27 STATUS_MFR_SPECIFIC (Address = 80h)
      31. 8.1.28 READ_VOUT (Address = 8Bh)
      32. 8.1.29 READ_IOUT (Address = 8Ch)
      33. 8.1.30 READ_TEMP1 (Address = 8Dh)
      34. 8.1.31 PMBUS_REVISION (Address = 98h)
      35. 8.1.32 MFR_ID (Address = 99h)
      36. 8.1.33 MFR_MODEL (Address = 9Ah)
      37. 8.1.34 MFR_REVISION (Address = 9Bh)
      38. 8.1.35 IC_DEVICE_ID (Address = ADh)
      39. 8.1.36 IC_DEVICE_REV (Address = AEh)
      40. 8.1.37 SYS_CFG_USER1 (Address = D1h)
      41. 8.1.38 PASSKEY (Address = D2h)
      42. 8.1.39 COMP (Address = D4h)
      43.      90
      44. 8.1.40 VBOOT (Address = D5h)
      45.      92
      46. 8.1.41 NVM_CHECKSUM (Address = D9h)
      47. 8.1.42 FUSION_ID0 (Address = FCh)
      48. 8.1.43 FUSION_ID1 (Address = FDh)
  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. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
      3. 9.4.3 Thermal Performance On TI EVM
  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

7.3.14 Low-side MOSFET Zero-Crossing

The device uses a zero-crossing (ZC) circuit to perform the zero inductor current detection during skip-mode operation. The ZC threshold is set to a small negative value before the low-side MOSFET is turned off, entering discontinuous conduction mode (DCM) operation. After entering DCM, the ZC threshold hysteresis increases the threshold to a small positive value after entering DCM. As a result, the device delivers better light-load efficiency.

When the load current increases enough such that the device exits DCM, the ZC circuit must detect 16 consecutive cycles of negative inductor current below the ZC threshold before returning to DCM. Only one cycle without ZC detection is required to exit DCM.

When the output is enabled, the ZC circuit is also enabled during the first 32 switching cycles while the device is in soft start. If the device is configured for FCCM, ZC is disabled and the device transitions to FCCM when soft start is complete. See Soft Start for a description on soft-start completion. If there are not at least 32 switching cycles before soft-start is done, such as during start-up with a high output prebias, the ZC is not disabled until the first high-side MOSFET on-time after soft-start done is complete.