SLVSDZ4D February   2018  – February 2020

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. Table 3. Absolute Maximum Ratings
    2. Table 4. ESD Ratings
    3. Table 5. Recommended Operating Conditions
    4. Table 6. Thermal Information
    5. Table 7. Electrical Characteristics
    6. Table 8. SNS Timing Characteristics
    7. Table 9. Switching Characteristics
    8. 7.1      Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    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 Programmable Current Limit
          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 Voltage Transients
          1. 9.3.1.3.1 Load Dump
        4. 9.3.1.4 Driving Inductive Loads
        5. 9.3.1.5 Reverse Battery
        6. 9.3.1.6 Fault Event – Timing Diagrams (Version A/B/C)
      2. 9.3.2 Diagnostic Mechanisms
        1. 9.3.2.1 VOUTx 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 Fault Indication and SNS Mux
        4. 9.3.2.4 Resistor Sharing
        5. 9.3.2.5 High-Frequency, Low Duty-Cycle Current Sensing
    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
    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 RILIM Calculation
        3. 10.2.2.3 Diagnostics
          1. 10.2.2.3.1 Selecting the RSNS 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 Documentation Support
      1. 13.1.1 Related Documentation
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

9.3.2.3 Fault Indication and SNS Mux

The following faults will be communicated through the SNS output:

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

Open-load and short-to-battery are not indicated while the switch is enabled, although these conditions can still be detected through the sense current. Hence, if there is a fault indication corresponding to an enabled channel, then it must be either due to an overcurrent or overtemperature event.

The SNS pin will only indicate the fault if the SELx pins are selecting the relevant channel. When the device is set to measure temperature, the pin will be measuring the temperature of whichever channel is at a higher temperature.

Table 11. Version A/B/C SNS Mux

INPUTS OUTPUTS
DIA_EN SEL1 SEL2 FAULT DETECT(1) SNS
0 X X X High-Z
1 0 0 0 CH1 current
1 0 1 0 CH2 current
1 1 0 0 Device temperature
1 1 1 0 N/A
1 0 0 1 ISNSFH
1 0 1 1 ISNSFH
1 1 0 1 Device temperature
1 1 1 1 N/A
(1) Fault Detect encompasses multiple conditions:
  • Switch shutdown and waiting for retry
  • Active current limiting (Version C)
  • Open-load and short-to-battery