SLVSFJ6A November   2020  – June 2026 TPS27SA08

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Summary Table
  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 Switching Characteristics
    7. 6.7 SNS Timing Characteristics
    8. 6.8 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Protection Mechanisms
        1. 8.3.1.1 Thermal Shutdown
        2. 8.3.1.2 Current Limit
          1. 8.3.1.2.1 Current Limit Foldback
          2. 8.3.1.2.2 Undervoltage Lockout (UVLO)
          3. 8.3.1.2.3 VBB during Short-to-Ground
        3. 8.3.1.3 Energy Limit
        4. 8.3.1.4 Voltage Transients
          1. 8.3.1.4.1 Driving Inductive and Capacitive Loads
        5. 8.3.1.5 Reverse Supply
        6. 8.3.1.6 Fault Event – Timing Diagrams
      2. 8.3.2 Diagnostic Mechanisms
        1. 8.3.2.1 VOUT Short-to-supply and Open-Load
          1. 8.3.2.1.1 Detection With Switch Enabled
          2. 8.3.2.1.2 Detection With Switch Disabled
        2. 8.3.2.2 SNS Output
          1. 8.3.2.2.1 RSNS Value
            1. 8.3.2.2.1.1 High Accuracy Load Current Sense
            2. 8.3.2.2.1.2 SNS Output Filter
        3. 8.3.2.3 ST Pin
        4. 8.3.2.4 Fault Indication and SNS Mux
        5. 8.3.2.5 Resistor Sharing
        6. 8.3.2.6 High-Frequency, Low Duty-Cycle Current Sensing
    4. 8.4 Device Functional Modes
      1. 8.4.1 Off
      2. 8.4.2 Standby
      3. 8.4.3 Diagnostic
      4. 8.4.4 Standby Delay
      5. 8.4.5 Active
      6. 8.4.6 Fault
  10. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Ground Protection Network
      2. 9.1.2 Interface With Microcontroller
      3. 9.1.3 I/O Protection
      4. 9.1.4 Inverse Current
      5. 9.1.5 Loss of GND
      6. 9.1.6 Thermal Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Thermal Considerations
        2. 9.2.2.2 Diagnostics
          1. 9.2.2.2.1 Selecting the RISNS Value
      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
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Related Documentation
    2. 10.2 Trademarks
    3. 10.3 Electrostatic Discharge Caution
    4. 10.4 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

8.3.2.4 Fault Indication and SNS Mux

The following faults are communicated through the SNS and ST outputs:

  • Switch shutdown, due to:
    • Thermal shutdown
    • Current limit
    • Energy limit
  • Active current limiting
  • Open-Load / VOUT shorted-to-supply

Open-load / Short-to-supply are not indicated while the switch is enabled (though these conditions are detectable through the sense current). Hence, if there is a fault indication corresponding to an enabled channel, then it must be either switch shutdown or active current limiting.

The SNS pin only indicates the fault if the SELx = 00. Switch shutdown fault indication occurs on the ST pin regardless of the SELx pins; however, OL/STB fault indication is only available when the SELx = 00.

Table 8-2 SNS Mux
INPUTSOUTPUTS
DIA_ENSEL1SEL2FAULT DETECT(1)SNSST
0XX0High-zHigh-z
0XX1High-zPull low
1000Load currentHigh-z
1010Not UsedNot Used
1100Device temperatureHigh-z
1110Supply voltageHigh-z
1001ISNSFHPull low
1011Not UsedNot Used
1101Device temperaturePull low
1111Supply voltagePull low
(1) Fault detect encompasses the below conditions:
  • Switch shutdown and waiting for retry
  • Active current limiting
  • OL / STB