SLUAAY0 September   2025 UCC57102 , UCC57102-Q1 , UCC57102Z , UCC57102Z-Q1 , UCC57108 , UCC57108-Q1 , UCC57132 , UCC57132-Q1 , UCC57138 , UCC57138-Q1 , UCC57142 , UCC57142-Q1 , UCC57148 , UCC57148-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2TI Non-Isolated SiC MOSFET Gate Drivers Overview
  6. 3SiC MOSFET Gate Driver Design Considerations
    1. 3.1 Undervoltage Lockout (UVLO)
    2. 3.2 Negative Bias Supply (Bipolar Drive)
    3. 3.3 Short-Circuit Protection
      1. 3.3.1 Desaturation Protection
      2. 3.3.2 Overcurrent Protection
      3. 3.3.3 Soft Turn-Off
  7. 4PFC CCM Boost Low-Side Gate Driver Example
    1. 4.1 Gate Driver Requirements
    2. 4.2 Gate Driver Selection
    3. 4.3 Gate Driver Power Dissipation
  8. 5Summary
  9. 6References

3.3.2 Overcurrent Protection

Overcurrent protection (OCP) is another type of short-circuit protection that is current-based. Figure 3-3 shows the OCP circuit. A shunt resistor is used to measure ID, which yields the shunt voltage. When a short-circuit occurs, then large ID causes the shunt voltage to rise high. If the shunt voltage rises above the OCP voltage threshold, then the comparator indicates that short-circuit is detected.

The shunt resistor value is selected based on the required drain current to trigger OCP (typically just below the maximum drain current that the SiC MOSFET can handle), which can be calculated in Equation 3.

Equation 3. R S = V O C T H / I D ( O C )
OCP Circuit Figure 3-4 OCP Circuit