SLUAB11 November   2025 AMC23C12-Q1 , TMCS1126-Q1 , UCC21750-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Difference Between SiC and IGBT
    2. 1.2 System SCP Response Time Requirement
    3. 1.3 Different SCP Locations
  5. 2Short-Circuit Mechanism
  6. 3Short Circuit Detection Methods
    1. 3.1 Shunt-Based Method
    2. 3.2 Desaturation-Based Method
    3. 3.3 Hall-Effect Sensor-Based Method
  7. 4Test Setup
  8. 5Measurement Results
    1. 5.1 Shunt Based Measurements
    2. 5.2 Desaturation-Based Measurements
    3. 5.3 Hall-Effect-Sensor Measurements
    4. 5.4 Performance Comparison
  9. 6Conclusion
  10. 7References

3.3 Hall-Effect Sensor-Based Method

Hall-effect sensors are popular in OBC and DCDC applications to sense the current, and can also be used to detect the short-circuit current iSC. The hall-effect sensor detects short-circuit currents by sensing the magnetic field generated by current flowing through the sensing element [18]. Figure 3-5 shows the simplified circuit for hall-effect sensor-based method.

Simplified Circuit for Hall-Based Detection Figure 3-5 Simplified Circuit for Hall-Based Detection

As hall-effect based current sensor, a TMCS1126-Q1 with integrated comparator is used. The Short circuit Detection (OCD) circuit provides a comparator output that can be used to trigger a warning or system shutdown to prevent damage from excessive current flow caused by short circuits, motor stalls, or other system conditions. This digital response can be configured on both bidirectional and unidirectional devices to trip anywhere between half and over twice the analog measurement range.

The trigger threshold is set using external passive elements. Similar to the shunt-based design, the sensor is placed between the two capacitors CC and CB. As soon as the current iSC reaches the defined threshold current set in the hall-effect sensor, the over-current output pin is used to disable the gate driver and turn-off the SiC MOSFET.