SLVSJC6 December   2025 TPS544B27W

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 Timing Requirements
    7. 5.7 Switching Characteristics
    8. 5.8 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 Operating Frequency and Mode
      2. 6.3.2 Setting the Output Voltage
      3. 6.3.3 DC Load Line
      4. 6.3.4 Fault Management
      5. 6.3.5 Current Sense and Positive Overcurrent Protection
      6. 6.3.6 Negative Overcurrent Limit
      7. 6.3.7 Zero-Crossing Detection
      8. 6.3.8 Overtemperature Protection
      9. 6.3.9 PMBus® Interface
        1. 6.3.9.1 Setting the PMBus® Address
        2. 6.3.9.2 SMBus Alert Response Address
    4. 6.4 Device Functional Modes
      1. 6.4.1 Forced Continuous-Conduction Mode
      2. 6.4.2 DCM Light Load Operation
    5. 6.5 Programming
      1. 6.5.1 PMBus® Command NVM Defaults
  8. 7 Register Maps
    1. 7.1 PMBus® Transaction Types
    2. 7.2 Conventions for Documenting Block Commands
    3. 7.3 PMBus Commands
      1. 7.3.1  OPERATION (Address = 01h)
      2. 7.3.2  ON_OFF_CONFIG (Address = 02h)
      3. 7.3.3  CLEAR_FAULTS (Address = 03h)
      4.      42
      5. 7.3.4  PASSKEY (Address = 0Eh)
      6. 7.3.5  WRITE_PROTECT (Address = 10h)
      7. 7.3.6  STORE_USER_ALL (Address = 15h)
      8.      46
      9. 7.3.7  RESTORE_USER_ALL (Address = 16h)
      10.      48
      11. 7.3.8  CAPABILITY (Address = 19h)
      12. 7.3.9  SMBALERT_MASK (Address = 1Bh)
      13.      51
      14. 7.3.10 SMBALERT_MASK Registers
        1. 7.3.10.1  ALERT_MASK_BYTE (Address = 78h) [Reset = C8h]
        2. 7.3.10.2  ALERT_MASK_WORD (Address = 79h) [Reset = 0Dh]
        3. 7.3.10.3  ALERT_MASK_VOUT (Address = 7Ah) [Reset = XXh]
        4. 7.3.10.4  ALERT_MASK_IOUT (Address = 7Bh) [Reset = XFh]
        5. 7.3.10.5  ALERT_MASK_INPUT (Address = 7Ch) [Reset = XXh]
        6. 7.3.10.6  ALERT_MASK_TEMPERATURE (Address = 7Dh) [Reset = XFh]
        7. 7.3.10.7  ALERT_MASK_CML (Address = 7Eh) [Reset = XXh]
        8. 7.3.10.8  ALERT_MASK_OTHER (Address = 7Fh) [Reset = XFh]
        9. 7.3.10.9  ALERT_MASK_MFR_SPECIFIC (Address = 80h) [Reset = XXh]
        10. 7.3.10.10 ALERT_MASK_PULSE_CATCHER (Address = CEh) [Reset = FXh]
      15. 7.3.11 VOUT_MODE (Address = 20h)
      16. 7.3.12 VOUT_COMMAND (Address = 21h)
      17. 7.3.13 VOUT_TRIM (Address = 22h)
      18. 7.3.14 VOUT_MAX (Address = 24h)
      19.      67
      20. 7.3.15 VOUT_MARGIN_HIGH (Address = 25h)
      21.      69
      22. 7.3.16 VOUT_MARGIN_LOW (Address = 26h)
      23.      71
      24. 7.3.17 VOUT_TRANSITION_RATE (Address = 27h)
      25.      73
      26. 7.3.18 VOUT_DROOP (Address = 28h)
      27. 7.3.19 VOUT_SCALE_LOOP (Address = 29h)
      28.      76
      29. 7.3.20 FREQUENCY_SWITCH (Address = 33h)
      30.      78
      31. 7.3.21 VIN_ON (Address = 35h)
      32.      80
      33. 7.3.22 VIN_OFF (Address = 36h)
      34.      82
      35. 7.3.23 VOUT_OV_FAULT_LIMIT (Address = 40h)
      36.      84
      37. 7.3.24 VOUT_OV_FAULT_RESPONSE (Address = 41h)
      38. 7.3.25 VOUT_OV_WARN_LIMIT (Address = 42h)
      39.      87
      40. 7.3.26 VOUT_UV_WARN_LIMIT (Address = 43h)
      41.      89
      42. 7.3.27 VOUT_UV_FAULT_LIMIT (Address = 44h)
      43.      91
      44. 7.3.28 VOUT_UV_FAULT_RESPONSE (Address = 45h)
      45. 7.3.29 IOUT_OC_FAULT_LIMIT (Address = 46h)
      46.      94
      47. 7.3.30 IOUT_OC_FAULT_RESPONSE (Address = 47h)
      48. 7.3.31 IOUT_OC_WARN_LIMIT (Address = 4Ah)
      49. 7.3.32 OT_FAULT_LIMIT (Address = 4Fh)
      50.      98
      51. 7.3.33 OT_FAULT_RESPONSE (Address = 50h)
      52. 7.3.34 OT_WARN_LIMIT (Address = 51h)
      53.      101
      54. 7.3.35 VIN_OV_FAULT_LIMIT (Address = 55h)
      55.      103
      56. 7.3.36 TON_DELAY (Address = 60h)
      57.      105
      58. 7.3.37 TON_RISE (Address = 61h)
      59. 7.3.38 TOFF_DELAY (Address = 64h)
      60. 7.3.39 TOFF_FALL (Address = 65h)
      61. 7.3.40 PIN_OP_WARN_LIMIT (Address = 6Bh)
      62.      110
      63.      111
      64.      112
      65. 7.3.41 STATUS_BYTE (Address = 78h)
      66. 7.3.42 STATUS_WORD (Address = 79h)
      67. 7.3.43 STATUS_VOUT (Address = 7Ah)
      68. 7.3.44 STATUS_IOUT (Address = 7Bh)
      69. 7.3.45 STATUS_INPUT (Address = 7Ch)
      70. 7.3.46 STATUS_TEMPERATURE (Address = 7Dh)
      71. 7.3.47 STATUS_CML (Address = 7Eh)
      72. 7.3.48 STATUS_OTHER (Address = 7Fh)
      73. 7.3.49 STATUS_MFR_SPECIFIC (Address = 80h)
      74. 7.3.50 READ_VIN (Address = 88h)
      75. 7.3.51 READ_IIN (Address = 89h)
      76. 7.3.52 READ_VOUT (Address = 8Bh)
      77. 7.3.53 READ_IOUT (Address = 8Ch)
      78. 7.3.54 READ_TEMPERATURE_1 (Address = 8Dh)
      79. 7.3.55 READ_PIN (Address = 97h)
      80. 7.3.56 PMBUS_REVISION (Address = 98h)
      81. 7.3.57 MFR_ID (Address = 99h)
      82. 7.3.58 MFR_MODEL (Address = 9Ah)
      83.      131
      84. 7.3.59 MFR_REVISION (Address = 9Bh)
      85. 7.3.60 IC_DEVICE_ID (Address = ADh)
      86. 7.3.61 IC_DEVICE_REV (Address = AEh)
      87.      135
      88. 7.3.62 EXTENDED_WRITE_PROTECT (Address = C7h)
      89. 7.3.63 NVM_PATCH_SPACE (Address = CDh)
      90. 7.3.64 CLOUD_OPTIONS (Address = CFh)
      91. 7.3.65 SYS_CFG_USER1 (Address = D0h)
      92.      140
      93. 7.3.66 SVID_ADDR_CFG_USER (Address = D1h)
      94. 7.3.67 PMBUS_ADDR (Address = D2h)
      95. 7.3.68 IMON_CAL (Address = D4h)
      96. 7.3.69 COMP (Address = D5h)
      97.      145
      98. 7.3.70 VBOOT_DCLL (Address = D6h)
      99. 7.3.71 VBOOT_OFFSET_1 (Address = D7h)
      100. 7.3.72 IIN_CAL (Address = D8h)
      101. 7.3.73 SVID_IMAX (Address = DAh)
      102.      150
      103. 7.3.74 SVID_EXT_CAPABILITY_VIDOMAX (Address = DBh)
      104. 7.3.75 FUSION_ID0 (Address = FCh)
      105. 7.3.76 FUSION_ID1 (Address = FDh)
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Application
      2. 8.2.2 Design Requirements
      3. 8.2.3 Detailed Design Procedure
        1. 8.2.3.1 Inductor Selection
        2. 8.2.3.2 Input Capacitor Selection
        3. 8.2.3.3 Output Capacitor Selection
        4. 8.2.3.4 VCC/VDRV Bypass Capacitor
        5. 8.2.3.5 BOOT Capacitor Selection
        6. 8.2.3.6 RSENSE Selection
        7. 8.2.3.7 I_IN_P and I_IN_M Capacitor Selection
        8. 8.2.3.8 VRRDY Pullup Resistor Selection
        9. 8.2.3.9 PMBus® Address Resistor Selection
      4. 8.2.4 Application Curves
        1. 8.2.4.1 Thermal Performance
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

6.3.6 Negative Overcurrent Limit

The TPS544B27W device is a synchronous buck converter, thus current can flow from the device to the load or from the load into the device through the SW node. When current flows from the SW node to the load, the device sources current (positive output current). When current flows from the load into the SW node, the device sinks current (negative output current).

The device features a programmable, cycle-by-cycle negative overcurrent (NOC) protection limit, configurable through the SEL_NOC bits in the SYS_CFG_USER1 command. Similar to positive overcurrent protection, the device monitors inductor current during the low-side MOSFET ON period to limit the valley inductor current. When detected current exceeds the selected NOC limit, the device turns off the low-side MOSFET to prevent excessive negative current that can damage the device. Following NOC turning off the low-side MOSFET as a protective action, the high-side MOSFET turns on for the duration set by the adaptive on-time generator, which is based on input voltage (VIN), sensed output voltage (VOUT), and the selected switching frequency (fSW).

NOC protection typically activates after an overvoltage event but can also engage during VOUT step-down transitions with fast slew rates.

CAUTION:

Avoid selecting an NOC limit less than half the worst-case peak-to-peak inductor ripple current. Setting too low a limit causes the device to restrict valley inductor current during light-load or no-load conditions in normal operation. When negative inductor current becomes limited, the low-side ON period shortens and volt-second balance across the inductor is disrupted. This imbalance causes the output voltage to drift upward until the volt-seconds during high-side on-time equals the volt-seconds during high-side off-time. To avoid this behavior, TI recommends selecting the highest NOC limit by setting SEL_NOC = 00b and ICC_MAX ≥ 010b.