SLVSE18B June   2019  – February 2023 TPS1HB35-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1. 6.1 Recommended Connections for Unused Pins
  7. 7 Specifications
    1. 7.1 Recommended Operating Conditions
    2. 7.2 Electrical Characteristics
    3. 7.3 Absolute Maximum Ratings
    4. 7.4 ESD Ratings
    5. 7.5 Thermal Information
    6. 7.6 SNS Timing Characteristics
    7. 7.7 Switching Characteristics
    8. 7.8 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
          2. 9.3.1.3.2 Driving Inductive Loads
        4. 9.3.1.4 Reverse Battery
        5. 9.3.1.5 Current Limit Behavior
        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 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
      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 RILIM Calculation
        3. 10.2.2.3 Diagnostics
          1. 10.2.2.3.1 Selecting the RISNS Value
    3. 10.3 Typical Application
      1. 10.3.1 Design Requirements
      2. 10.3.2 Detailed Design Procedure
      3. 10.3.3 Application Curves
    4. 10.4 Power Supply Recommendations
    5. 10.5 Layout
      1. 10.5.1 Layout Guidelines
      2. 10.5.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
9.3.1.2.2 Programmable Current Limit

All versions of the TPS1HB35-Q1 include an adjustable current limit. Some applications (for example, incandescent bulbs) will require a high current limit while other applications can benefit from a lower current limit threshold. In general, wherever possible a lower current limit is recommended due to allowing system advantages through:

  • Reduced size and cost in current carrying components such as PCB traces and module connectors
  • Less disturbance at the power supply (VBB pin) during a short-circuit event
  • Improved protection of the downstream load

To set the current limit threshold, connect a resistor from ILIM to VBB. The current limit threshold is determined by Equation 1 (RILIM in kΩ):

Equation 1. ICL = KCL / RILIM

The RILIM range is between 5 kΩ and 25 kΩ . An RILIM resistor is required, however in the fault case where the pin is floating, grounded, or outside of this range the current limit will default to an internal level that is defined in the Specifications section of this document. If RILIM is out of this range, the device cannot assure complete short-circuit protection.

Note:

Capacitance on the ILIM pin can cause ILIM to go out of range during short-circuit events. For accurate current limiting, place RILIM near to the device with short traces to ensure < 5-pF capacitance to GND on the ILIM pin.