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

7.3.17 Overvoltage/Undervoltage Protection

The TPS40425 device monitors the voltage on the FB pin to provide undervoltage (UV) and overvoltage (OV) protection.

The UV protection scheme is the same as OC protection scheme. When UV fault is triggered, both the high-side and low-side MOSFETs are turned off. The IOUT_OC_FAULT_RESPONSE setting determines the controller response to UV fault. For example, if the IOUT_OC_FAULT_RESPONSE is set to restart the controller after OC fault, then the controller is internally also programmed to restart after a UV fault.

When an OV fault is triggered, the high-side MOSFET is turned off and the low-side MOSFET remains on to discharge the output. When the output returns to the regulation (PGOOD) window, the TPS40425 device begins a hard startup. This behavior is intended to protect the output against overvoltage. The response to output voltage OV fault is not programmable.

The UV and OV fault threshold values can be set by PMBus command MFR_SPECIFIC_07(PCT_VOUT_FAULT_PG_LIMIT).

When operating in dual-output mode, only the FB pin of master channel is detected for output voltage UV and OV fault. Therefore all channels take action together during a fault. Output voltage related faults are not detected on any channel configured as a slave.