SLVSE16D May   2019  – August 2026 TPS1HB08-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
    1. 5.1 Recommended Connections for Unused Pins
  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 SNS Timing Characteristics
    7. 6.7 Switching 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 Programmable Current Limit
          3. 8.3.1.2.3 Undervoltage Lockout (UVLO)
          4. 8.3.1.2.4 VBB During Short-to-Ground
        3. 8.3.1.3 Voltage Transients
          1. 8.3.1.3.1 Load Dump
          2. 8.3.1.3.2 Driving Inductive Loads
        4. 8.3.1.4 Reverse Battery
        5. 8.3.1.5 Fault Event – Timing Diagrams - Version A and B
        6. 8.3.1.6 Fault Event – Timing Diagrams - Version F
      2. 8.3.2 Diagnostic Mechanisms
        1. 8.3.2.1 VOUT Short-to-Battery 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 Fault Indication and SNS Mux
        4. 8.3.2.4 Resistor Sharing
        5. 8.3.2.5 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 Automotive Standards
        1. 9.1.6.1 ISO7637-2
        2. 9.1.6.2 TPS1HB08-Q1 AEC-Q100-012 Short-Circuit Reliability
      7. 9.1.7 Interference on Device Pins
      8. 9.1.8 Thermal Information
    2. 9.2 Typical Application: Resistive Heater Loads
      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 RILIM Calculation
        3. 9.2.2.3 Diagnostics
          1. 9.2.2.3.1 Selecting the RISNS Value
    3. 9.3 Typical Application: Headlight Bulb Loads
      1. 9.3.1 Design Requirements
      2. 9.3.2 Detailed Design Procedure
      3. 9.3.3 Application Curves
    4. 9.4 Power Supply Recommendations
    5. 9.5 Layout
      1. 9.5.1 Layout Guidelines
      2. 9.5.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information
8.3.2.1.2 Detection With Switch Disabled

While the switch is disabled, if DIA_EN is high, an internal comparator detects the condition of VOUT. If the load is disconnected (open load condition) or there is a short to battery the VOUT voltage is higher than the open load threshold (VOL,off) and a fault is indicated on the SNS pin and the FLT pin on version F. An internal pull-up of 1MΩ is in series with an internal MOSFET switch, so no external component is required if a completely open load must be detected. However, if there is significant leakage or other current draw even when the load is disconnected, a lower value pull-up resistor and switch can be added externally to set the VOUT voltage above the VOL,off during open load conditions.

TPS1HB08-Q1 Short to Battery and Open Load Detection
This figure assumes that the device ground and the load ground are at the same potential. In a real system, there can be a ground shift voltage from 1V to 2V.
Figure 8-8 Short to Battery and Open Load Detection

The detection circuitry is only enabled when DIA_EN = HIGH and EN = LOW. If VOUT > VOL, the SNS pin goes to the fault level, but if VOUT < VOL there is no fault indication. The fault indication will only occur if the SEL1 pin is low.

While the switch is disabled and DIA_EN is high, the fault indication mechanisms will continuously represent the present status. For example, if VOUT decreases from greater than VOL to less than VOL, the fault indication is reset. Additionally, the fault indication is reset upon the falling edge of DIA_EN or the rising edge of EN.

TPS1HB08-Q1 Open LoadFigure 8-9 Open Load