SLVSDM4D November   2018  – December 2019 TPS1HA08-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Simplified Schematic
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
    2. 6.1 Recommended Connections for Unused Pins
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Switching Characteristics
    7. 7.7 SNS Timing Characteristics
    8. 7.8 Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
      1. 9.1.1 Device Nomenclature
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Protection Mechanisms
        1. 9.3.1.1 Thermal Shutdown
        2. 9.3.1.2 Current Limit
          1. 9.3.1.2.1 Current Limit Foldback
          2. 9.3.1.2.2 Selectable Current Limit Threshold
          3. 9.3.1.2.3 Undervoltage Lockout (UVLO)
          4. 9.3.1.2.4 VBB during Short-to-Ground
        3. 9.3.1.3 Energy Limit
        4. 9.3.1.4 Voltage Transients
          1. 9.3.1.4.1 Load Dump
          2. 9.3.1.4.2 Driving Inductive and Capacitive Loads
        5. 9.3.1.5 Reverse Battery
        6. 9.3.1.6 Fault Event – Timing Diagrams
      2. 9.3.2 Diagnostic Mechanisms
        1. 9.3.2.1 VOUT Short-to-Battery and Open-Load
          1. 9.3.2.1.1 Detection With Switch Enabled
          2. 9.3.2.1.2 Detection With Switch Disabled
        2. 9.3.2.2 SNS Output
          1. 9.3.2.2.1 RSNS Value
            1. 9.3.2.2.1.1 High Accuracy Load Current Sense
            2. 9.3.2.2.1.2 SNS Output Filter
        3. 9.3.2.3 ST Pin
        4. 9.3.2.4 Fault Indication and SNS Mux
        5. 9.3.2.5 Resistor Sharing
        6. 9.3.2.6 High-Frequency, Low Duty-Cycle Current Sensing
      3. 9.3.3 Enable Watchdog
    4. 9.4 Device Functional Modes
      1. 9.4.1 Off
      2. 9.4.2 Standby
      3. 9.4.3 Diagnostic
      4. 9.4.4 Standby Delay
      5. 9.4.5 Active
      6. 9.4.6 Fault
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Ground Protection Network
      2. 10.1.2 Interface With Microcontroller
      3. 10.1.3 I/O Protection
      4. 10.1.4 Inverse Current
      5. 10.1.5 Loss of GND
      6. 10.1.6 Automotive Standards
        1. 10.1.6.1 ISO7637-2
        2. 10.1.6.2 AEC – Q100-012 Short Circuit Reliability
      7. 10.1.7 Thermal Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Thermal Considerations
        2. 10.2.2.2 Diagnostics
          1. 10.2.2.2.1 Selecting the RISNS Value
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Related Documentation
    2. 13.2 Trademarks
    3. 13.3 Electrostatic Discharge Caution
    4. 13.4 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

9.3.2.2 SNS Output

The SNS output may be used to sense the load current, supply voltage, or device temperature. The SELx pins will select the desired sense signal. The sense circuit will provide a current that is proportional to the selected parameter. This current will be sourced into an external resistor to create a voltage that is proportional to the selected parameter. This voltage may be measured by an ADC or comparator.

To ensure accurate sensing measurement, the sensing resistor should be connected to the same ground potential as the μC ADC.

The SNS Output includes an internal clamp, VSNSclamp. This clamp is designed to prevent a high voltage at the SNS output and the ADC input.

Table 2. Analog Sense Transfer Function

PARAMETER TRANSFER FUNCTION
Load current ISNSI = IOUT / 4600
Supply voltage(1) ISNSV = (VBB) × dISNSV / dV
Device temperature ISNST = (TJ – 25°C) × dISNST / dT + 0.85
(1) Voltage potential between the VBB pin and the GND pin.

The SNS output will also be used to indicate system faults. ISNS will go to the predefined level, ISNSFH, when there is a fault. This level is defined in the electrical specifications.