SLUSBO6C JANUARY   2014  – October 2018 TPS40425

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1. 3.1 Simplified Application Diagram (Dual Output)
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 Handling Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Asynchronous Pulse Injection (API)
      2. 7.3.2  Adaptive Voltage Scaling (AVS)
      3. 7.3.3  Switching Frequency and Synchronization
      4. 7.3.4  Voltage Reference
      5. 7.3.5  Output Voltage and Remote Sensing Amplifier
      6. 7.3.6  Current Sensing and Temperature Sensing Modes
        1. 7.3.6.1 Non Smart-Power Operation
        2. 7.3.6.2 Smart-Power Operation.
      7. 7.3.7  Current Sensing
      8. 7.3.8  Temperature Sensing
      9. 7.3.9  Current Sharing
      10. 7.3.10 Linear Regulators
      11. 7.3.11 Power Sequence Between TPS40425 Device and Power Stage
      12. 7.3.12 PWM Signal
        1. 7.3.12.1 PWM Behavior During Soft-start Operation
      13. 7.3.13 Startup and Shutdown
      14. 7.3.14 Pre-Biased Output Start-up
      15. 7.3.15 PGOOD Indication
      16. 7.3.16 Overcurrent Protection
      17. 7.3.17 Overvoltage/Undervoltage Protection
      18. 7.3.18 Overtemperature Fault Protection
      19. 7.3.19 Input Undervoltage Lockout (UVLO)
      20. 7.3.20 Fault Communication
      21. 7.3.21 Fault Protection Summary
    4. 7.4 Device Functional Modes
    5. 7.5 Programming
      1. 7.5.1 Multi-Phase Applications
    6. 7.6 Register Maps
      1. 7.6.1 PMBus General Description
      2. 7.6.2 PMBus Functionality
        1. 7.6.2.1 PMBus Address
        2. 7.6.2.2 PMBus Connections
        3. 7.6.2.3 PMBus Data Format
        4. 7.6.2.4 PMBus Output Voltage Adjustment
          1. 7.6.2.4.1 No Margin Voltage
          2. 7.6.2.4.2 Margin High Voltage State
          3. 7.6.2.4.3 Margin Low State
      3. 7.6.3 Reading the Output Current
      4. 7.6.4 Soft-Start Time
      5. 7.6.5 Turn-On/Turn-Off Delay and Sequencing
    7. 7.7 Supported PMBus Commands
      1. 7.7.1  PAGE (00h)
      2. 7.7.2  OPERATION (01h)
      3. 7.7.3  ON_OFF_CONFIG (02h)
      4. 7.7.4  CLEAR_FAULTS (03h)
      5. 7.7.5  WRITE_PROTECT (10h)
      6. 7.7.6  STORE_USER_ALL (15h)
      7. 7.7.7  RESTORE_USER_ALL (16h)
      8. 7.7.8  CAPABILITY (19h)
      9. 7.7.9  VOUT_MODE (20h)
      10. 7.7.10 VIN_ON (35h)
      11. 7.7.11 VIN_OFF (36h)
      12. 7.7.12 IOUT_CAL_GAIN (38h)
      13. 7.7.13 IOUT_CAL_OFFSET (39h)
      14. 7.7.14 IOUT_OC_FAULT_LIMIT (46h)
      15. 7.7.15 IOUT_OC_FAULT_RESPONSE (47h)
      16. 7.7.16 IOUT_OC_WARN_LIMIT (4Ah)
      17. 7.7.17 OT_FAULT_LIMIT (4Fh)
      18. 7.7.18 OT_WARN_LIMIT (51h)
      19. 7.7.19 TON_RISE (61h)
      20. 7.7.20 STATUS_BYTE (78h)
      21. 7.7.21 STATUS_WORD (79h)
      22. 7.7.22 STATUS_VOUT (7Ah)
      23. 7.7.23 STATUS_IOUT (7Bh)
      24. 7.7.24 STATUS_TEMPERATURE (7Dh)
      25. 7.7.25 STATUS_CML (7Eh)
      26. 7.7.26 STATUS_MFR_SPECIFIC (80h)
      27. 7.7.27 READ_VOUT (8Bh)
      28. 7.7.28 READ_IOUT (8Ch)
      29. 7.7.29 READ_TEMPERATURE_2 (8Eh)
      30. 7.7.30 PMBus_REVISION (98h)
      31. 7.7.31 MFR_SPECIFIC_00 (D0h)
      32. 7.7.32 MFR_SPECIFIC_04 (VREF_TRIM) (D4h)
      33. 7.7.33 MFR_SPECIFIC_05 (STEP_VREF_MARGIN_HIGH) (D5h)
      34. 7.7.34 MFR_SPECIFIC_06 (STEP_VREF_MARGIN_LOW) (D6h)
      35. 7.7.35 MFR_SPECIFIC_07 (PCT_VOUT_FAULT_PG_LIMIT) (D7h)
      36. 7.7.36 MFR_SPECIFIC_08 (SEQUENCE_TON_TOFF_DELAY) (D8h)
      37. 7.7.37 MFR_SPECIFIC_16 (COMM_EEPROM_SPARE) (E0h)
      38. 7.7.38 MFR_SPECIFIC_21 (OPTIONS) (E5h)
      39. 7.7.39 MFR_SPECIFIC_22 (PWM_OSC_SELECT) (E6h)
      40. 7.7.40 MFR_SPECIFIC_23 (MASK SMBALERT) (E7h)
      41. 7.7.41 MFR_SPECIFIC_25 (AVS_CONFIG) (E9h)
      42. 7.7.42 MFR_SPECIFIC_26 (AVS_ADDRESS) (EAh)
      43. 7.7.43 MFR_SPECIFIC_27 (AVS_DAC_DEFAULT) (EBh)
      44. 7.7.44 MFR_SPECIFIC_28 (AVS_CLAMP_HI) (ECh)
      45. 7.7.45 MFR_SPECIFIC_29 (AVS_CLAMP_LO) (EDh)
      46. 7.7.46 MFR_SPECIFIC_30 (TEMP_OFFSET) (EEh)
      47. 7.7.47 MFR_SPECIFIC_32 (API_OPTIONS) (F0h)
      48. 7.7.48 MFR_SPECIFIC_44 (DEVICE_CODE) (FCh)
  8. 8 Applications and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Dual-Output Application
      2. 8.2.2 Design Requirements
      3. 8.2.3 Design Procedure
        1. 8.2.3.1  Switching Frequency Selection
        2. 8.2.3.2  Inductor Selection
        3. 8.2.3.3  Output Capacitor Selection
          1. 8.2.3.3.1 Output Voltage Deviation During Load Transient
          2. 8.2.3.3.2 Output Voltage Ripple
        4. 8.2.3.4  Input Capacitor Selection
        5. 8.2.3.5  VDD, BP5, BP3 Bypass Capacitor
        6. 8.2.3.6  R-C Snubber
        7. 8.2.3.7  Current and Temperature Sensor
        8. 8.2.3.8  Power Sequence Between the TPS40425 Device and Power Stage
        9. 8.2.3.9  Output Voltage Setting and Frequency Compensation Selection
        10. 8.2.3.10 Key PMBus Parameter Selection
          1. 8.2.3.10.1 MFR_SPECIFIC_21 (OPTIONS)
            1. 8.2.3.10.1.1 IOUT_CAL_GAIN
            2. 8.2.3.10.1.2 Enable and UVLO
            3. 8.2.3.10.1.3 Soft-Start Time
            4. 8.2.3.10.1.4 Overcurrent Threshold and Response
      4. 8.2.4 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Layout Guidelines for TPS40425 Device
      2. 10.1.2 Layout Guidelines for Power Stage Device
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
        1. 11.1.1.1 Texas Instruments Fusion Digital Power Designer
        2. 11.1.1.2 TPS40k Loop Compensation Tool
    2. 11.2 Trademarks
    3. 11.3 Electrostatic Discharge Caution
    4. 11.4 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.2.3.10.1.4 Overcurrent Threshold and Response

The IOUT_OC_FAULT_LIMIT command sets the overcurrent threshold. The TPS40425 device uses inductor peak current value for overcurrent detecting. The current limit should be set to the maximum inductor peak current, plus the output capacitor charging current during start-up, plus some margin for load transients and component variation. The amount of margin required depends on the individual application, but a suggested point is between 30% and 50%. For this application, the maximum inductor peak current is 27.33 A, the output capacitor charging current is 0.44 A. This design allows some extra margin, so an overcurrent threshold of 40 A (peak current) was selected.

The IOUT_OC_FAULT_RESPONE command sets the desired response to an overcurrent event. In this example, the converter is configured to hiccup in the event of an overcurrent. TPS40425 device can also be configured to latch in the event of an overcurrent.