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

7.3.9 Enable

When the EN pin voltage rises above the enable threshold voltage (VEN(R)) and VIN rises above the VIN UVLO rising threshold, the device enters the internal power-up sequence.

The EN pin has an internal filter to avoid unexpected ON or OFF due to small glitches. The time constant of this RC filter is 2µs. For example, when applying 3.3V voltage source on the EN pin that jumps from 0V to 3.3V with an ideal rising edge, the internal EN signal reaches 2.1V after 2µs, which is 63.2% of applied 3.3V voltage level.

An internal pulldown resistor is implemented between the EN pin and AGND pin. With this pulldown resistor, floating the EN pin before start-up keeps the device in the disabled state. A resistor divider to the EN pin can be used to increase the input voltage the device begins the start-up sequence. The internal pulldown resistor must be accounted for when using an external resistor divider. To reduce impact to the EN rising and falling threshold, this internal pulldown resistor is 1MΩ. During nominal operation when the power stage switches, this large internal pulldown resistor can not have enough noise immunity to hold EN pin low for the device to enter the disabled state.

If an external resistor divider is connected to the EN pin, an additional 5µA current source is activated when the EN voltage exceeds the rising threshold to provide a programmable hysteresis based on the enable falling threshold voltage (VEN(F)) and external resistors.

The recommended operating condition for the EN pin is a maximum of 5.5V. Do not connect the EN pin to the VIN pin directly if VIN can exceed 5.5V.