SLVAEX0 October   2020 TPS1H000-Q1 , TPS1H100-Q1 , TPS1H200A-Q1 , TPS1HA08-Q1 , TPS1HB16-Q1 , TPS1HB50-Q1 , TPS2HB16-Q1 , TPS2HB50-Q1 , TPS4H000-Q1 , TPS4H160-Q1

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
  4. 2Normal Operation Diagnostics
    1. 2.1 Configuring Diagnostics With SEL/SELx Pin
      1. 2.1.1 Diagnostics Select Pin: SEL1
      2. 2.1.2 Diagnostics Select Pin: SELx
    2. 2.2 Operating Current Measurements Using the SNS/CS Pin
      1. 2.2.1 Internal/External Factor: Load Current Through Device
      2. 2.2.2 External Factor: Analog-to-Digital Converter (ADC)
      3. 2.2.3 External Factor: Probe Ground Termination
      4. 2.2.4 External Factor: Component Tolerances
    3. 2.3 Device Temperature on the Sense (SNS) Pin
  5. 3Fault State Diagnostics
    1. 3.1 Fault Behavior Configurations: Latch/THER/Delay Pin
      1. 3.1.1 Latch Pin
      2. 3.1.2 THER Pin
      3. 3.1.3 Delay Pin
    2. 3.2 Open Load Fault
    3. 3.3 Short to Battery Fault
    4. 3.4 Thermal Shutdown
    5. 3.5 Loss of Ground or Power Supply
    6. 3.6 Summary
  6. 4References

External Factor: Probe Ground Termination

With the CS or SNS pin, measuring the pin on an oscilloscope in a lab environment can help diagnose issues but also brings another external factor that can affect the measured value of the CS or SNS pin. More specifically, in a lab environment, the errors can stem from the hardware such as oscilloscope probes that will have some resistance and capacitance associated with the probe tip. With the case of oscilloscopes, the major factor is the ground termination on the probes. Oscilloscope probes have an internal capacitance that allows for compensation. Ground traces or leads can create an inductance. The result of the internal capacitor and the ground inductance, voltages seen by an oscilloscope probe can have a ringing voltage. By using a shorter ground lead or using a ground spring accessory, the inductance that would result from a long PCB ground trace can be minimized and the chances of inaccuracies reduce.