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

7.3.6.1 Setting VBOOT and VOUT_SCALE_LOOP

The TPS544A28 supports 32 unique start-up voltage settings through (D5h) VBOOT. Of these, 24 are available through pinstrap by default, and all can be programmed into NVM. These settings determine both the start-up voltage the device begins regulating to during soft-start and the (29h) VOUT_SCALE_LOOP the device uses for the current power-on cycle. The (29h) VOUT_SCALE_LOOP value is latched during pinstrap detection at startup and cannot be changed until the next power-on cycle.

To provide the user greater flexibility, (D1h) SYS_CFG_USER1 contains an NRSA_L bit that adjusts the (29h) VOUT_SCALE_LOOP used for some boot voltages. This changes the range of possible voltages the user can access through (21h) VOUT_COMMAND in a power-on cycle, allowing them to slew to lower voltages than possible by default. After setting NRSA_L high, the user must store to NVM via STORE_USER_ALL and power cycle for the change to take effect.

Note: Changing (29h) VOUT_SCALE_LOOP for a given VOUT with NRSA_L also changes the internal VREF_DAC setpoint and can impact the compensation settings as outlined in Section 7.3.1.

The (D5h) VBOOT and (29h) VOUT_SCALE_LOOP settings are specified in Table 7-6:

Table 7-6 VBOOT Enumeration List
VBOOT [4:0] (dec) VOUT_SCALE_LOOP (V/V) VOUT (V)
NRSA_L = 0b NRSA_L = 1b
0 1 1 0.4
1 1 1 0.45
2 1 1 0.5
3 1 1 0.55
4 1 1 0.6
5 1 1 0.65
6 1 1 0.7
7 1 1 0.75
8 1 1 0.8
9 0.5 1 0.85
10 0.5 1 0.9
11 0.5 0.5 0.95
12 0.5 0.5 1.0
13 0.5 0.5 1.05
14 0.5 0.5 1.1
15 0.5 0.5 1.15
16 0.5 0.5 1.2
17 0.5 0.5 1.25
18 0.5 0.5 1.3
19 0.5 0.5 1.5
20 0.5 0.5 1.6
21 0.25 0.5 1.7
22 0.25 0.5 1.8
23 0.25 0.25 2
24 0.25 0.25 2.25
25 0.25 0.25 2.5
26 0.25 0.25 2.75
27 0.25 0.25 3.0
28 0.125 0.25 3.3
29 0.125 0.25 3.6
30 0.125 0.125 4.5
31 0.125 0.125 5.0