SLVSH95A July   2024  – September 2025 TPS546C25

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  D-CAP4 Control
        1. 6.3.1.1 Loop Compensation
      2. 6.3.2  Internal VCC LDO and Using an External Bias on the VDRV Pin
      3. 6.3.3  Input Undervoltage Lockout (UVLO)
        1. 6.3.3.1 Fixed VCC_OK UVLO
        2. 6.3.3.2 Fixed VDRV UVLO
        3. 6.3.3.3 Programmable PVIN UVLO
        4. 6.3.3.4 Control (CNTL) Enable
      4. 6.3.4  Differential Remote Sense and Internal, External Feedback Divider
      5. 6.3.5  Set the Output Voltage and VORST#
      6. 6.3.6  Start-Up and Shutdown
      7. 6.3.7  Dynamic Voltage Slew Rate
      8. 6.3.8  Set Switching Frequency
      9. 6.3.9  Switching Node (SW)
      10. 6.3.10 Overcurrent Limit and Low-side Current Sense
      11. 6.3.11 Negative Overcurrent Limit
      12. 6.3.12 Zero-Crossing Detection
      13. 6.3.13 Input Overvoltage Protection
      14. 6.3.14 Output Overvoltage and Undervoltage Protection
      15. 6.3.15 Overtemperature Protection
      16. 6.3.16 Telemetry
    4. 6.4 Device Functional Modes
      1. 6.4.1 Forced Continuous-Conduction Mode
      2. 6.4.2 DCM Light Load Operation
      3. 6.4.3 Powering the Device From a 12V Bus
      4. 6.4.4 Powering the Device From a Split-rail Configuration
      5. 6.4.5 2-Phase Configuration
      6. 6.4.6 Pin-Strapping
        1. 6.4.6.1 Programming MSEL1
        2. 6.4.6.2 Programming PMB_ADDR
        3. 6.4.6.3 Programming MSEL2
        4. 6.4.6.4 Programming VSEL\FB
    5. 6.5 Programming
      1. 6.5.1 Supported PMBus® Commands
  8. 7 Register Maps
    1. 7.1  Conventions for Documenting Block Commands
    2. 7.2  (01h) OPERATION
    3. 7.3  (02h) ON_OFF_CONFIG
    4. 7.4  (03h) CLEAR_FAULTS
    5. 7.5  (04h) PHASE
    6. 7.6  (09h) P2_PLUS_WRITE
    7. 7.7  (0Ah) P2_PLUS_READ
    8. 7.8  (0Eh) PASSKEY
    9. 7.9  (10h) WRITE_PROTECT
    10. 7.10 (15h) STORE_USER_ALL
    11. 7.11 (16h) RESTORE_USER_ALL
    12. 7.12 (19h) CAPABILITY
    13. 7.13 (1Bh) SMBALERT_MASK
    14. 7.14 (20h) VOUT_MODE
    15. 7.15 (21h) VOUT_COMMAND
    16. 7.16 (22h) VOUT_TRIM
    17. 7.17 (24h) VOUT_MAX
    18. 7.18 (25h) VOUT_MARGIN_HIGH
    19. 7.19 (26h) VOUT_MARGIN_LOW
    20. 7.20 (27h) VOUT_TRANSITION_RATE
    21. 7.21 (29h) VOUT_SCALE_LOOP
    22. 7.22 (2Ah) VOUT_SCALE_MONITOR
    23. 7.23 (2Bh) VOUT_MIN
    24. 7.24 (33h) FREQUENCY_SWITCH
    25. 7.25 (35h) VIN_ON
    26. 7.26 (36h) VIN_OFF
    27. 7.27 (39h) IOUT_CAL_OFFSET
    28. 7.28 (40h) VOUT_OV_FAULT_LIMIT
    29. 7.29 (41h) VOUT_OV_FAULT_RESPONSE
    30. 7.30 (42h) VOUT_OV_WARN_LIMIT
    31. 7.31 (43h) VOUT_UV_WARN_LIMIT
    32. 7.32 (44h) VOUT_UV_FAULT_LIMIT
    33. 7.33 (45h) VOUT_UV_FAULT_RESPONSE
    34. 7.34 (46h) IOUT_OC_FAULT_LIMIT
    35. 7.35 (48h) IOUT_OC_LV_FAULT_LIMIT
    36. 7.36 (49h) IOUT_OC_LV_FAULT_RESPONSE
    37. 7.37 (4Ah) IOUT_OC_WARN_LIMIT
    38. 7.38 (4Fh) OT_FAULT_LIMIT
    39. 7.39 (50h) OT_FAULT_RESPONSE
    40. 7.40 (51h) OT_WARN_LIMIT
    41. 7.41 (55h) VIN_OV_FAULT_LIMIT
    42. 7.42 (60h) TON_DELAY
    43. 7.43 (61h) TON_RISE
    44. 7.44 (64h) TOFF_DELAY
    45. 7.45 (65h) TOFF_FALL
    46. 7.46 (78h) STATUS_BYTE
    47. 7.47 (79h) STATUS_WORD
    48. 7.48 (7Ah) STATUS_VOUT
    49. 7.49 (7Bh) STATUS_IOUT
    50. 7.50 (7Ch) STATUS_INPUT
    51. 7.51 (7Dh) STATUS_TEMPERATURE
    52. 7.52 (7Eh) STATUS_CML
    53. 7.53 (7Fh) STATUS_OTHER
    54. 7.54 (80h) STATUS_MFR_SPECIFIC
    55. 7.55 (88h) READ_VIN
    56. 7.56 (8Bh) READ_VOUT
    57. 7.57 (8Ch) READ_IOUT
    58. 7.58 (8Dh) READ_TEMPERATURE_1
    59. 7.59 (98h) PMBUS_REVISION
    60. 7.60 (99h) MFR_ID
    61. 7.61 (9Ah) MFR_MODEL
    62. 7.62 (9Bh) MFR_REVISION
    63. 7.63 (ADh) IC_DEVICE_ID
    64. 7.64 (AEh) IC_DEVICE_REV
    65. 7.65 (D1h) SYS_CFG_USER1
    66. 7.66 (D3h) PMBUS_ADDR
    67. 7.67 (D4h) COMP
    68. 7.68 (D5h) VBOOT_OFFSET_1
    69. 7.69 (D6h) STACK_CONFIG
    70. 7.70 (D8h) PIN_DETECT_OVERRIDE
    71. 7.71 (D9h) NVM_CHECKSUM
    72. 7.72 (DAh) READ_TELEMETRY
    73. 7.73 (DBh) STATUS_ALL
    74. 7.74 (DDh) EXT_WRITE_PROTECTION
    75. 7.75 (DEh) IMON_CAL
    76. 7.76 (FCh) FUSION_ID0
    77. 7.77 (FDh) FUSION_ID1
  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 Input Capacitor Selection
        2. 8.2.3.2 Inductor Selection
        3. 8.2.3.3 Output Capacitor Selection
        4. 8.2.3.4 Compensation Selection
        5. 8.2.3.5 VCC and VDRV Bypass Capacitors
        6. 8.2.3.6 BOOT Capacitor Selection
        7. 8.2.3.7 VOSNS and GOSNS Capacitor Selection
        8. 8.2.3.8 PMBus® Address Resistor Selection
      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 Example
        1. 8.4.2.1 Thermal Performance on TPS546C25EVM
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

8.2.3.2 Inductor Selection

The inductor must be selected such that the transient performance and ripple requirements are balanced for a particular design. In general, a smaller inductance increases loop bandwidth leading to better transient response at the expense of higher current and voltage ripple.

Determine the amount of inductor ripple current desired for the converter. 25% to 40% of the maximum DC output current results in a good compromise between RMS losses (in the MOSFETs and inductor) and good load transient response.

Equation 13. L = ((vin-vout) × duty-cycle × Ts) / (delta-I)

Now select an inductor capable of withstanding the DC current. A good selection:

  • Has inductance droop of less than 20% of initial value at full load
  • Not saturate under overload conditions
  • Has low DC and core losses at the frequency of operation
  • Has a temperature rise within the bounds of the operating environment

In this example, a 120nH, 0.2mΩ inductor is used.