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

7.3.8 Dynamic Voltage Slew Rate

The TPS544A28 includes (27h) VOUT_TRANSITION_RATE to set the slew rate when changing the output voltage levels. The selectable options are outlined in Table 7-9.

Table 7-9 VOUT_TRANSITION_RATE Enumeration List
VOUT_TRANSITION_RATE [6:0] SLEW RATE (mV/μs)
≥ ≤
0d 19d 1.625
20d 38d 3.25
39d 77d 6.5
78d 127d 13

During the output voltage transition, due to the quick charge or discharge of output capacitors, the power stage sees extra inrush current. This inrush current plus load current can trigger overcurrent protection when there is no sufficient room from OCL or NOC setting. For example, the positive inductor current during VOUT step-up transition goes higher than nominal operation. If the LS valley OCL threshold is set relatively low and does not allow the extra inrush current, the inductor current is potentially limited by the cycle-by-cycle overcurrent limit feature, thus the actual step-up slew rate is lower than the desired value. Similar situations can happen to VOUT step-down transitions with no load condition. The negative inductor current during VOUT step-down transition goes more negative than nominal operation. However, the inductor current is not allowed to go more negative than the negative OC threshold. Thus, triggering NOC operation during VOUT step-down transition results that the actual step-down slew rate is lower than the desired value.