SBAA549 April   2022 AMC23C11 , AMC23C12 , AMC23C14

 

  1.   Trademarks
  2. 1Background
  3. 2Overcurrent Protection on DC+
  4. 3DC+ Power Supply Solution
    1. 3.1 Selection of Charge Pump Capacitor
    2. 3.2 Simulation in PSpice for TI
    3. 3.3 Hardware Test
    4. 3.4 Low-Cost Power Supply Solution
  5. 4Power-On Short-Circuit Risk and Solution
  6. 5Reference

2 Overcurrent Protection on DC+

Figure 2-1 shows how the OC protection based on the DC+ bus can protect three short-circuit situations: a shoot-through fault of IGBT (blue), DC+ ground fault (red), and phase-to-phase short fault (yellow).



Figure 2-1 DC+ Overcurrent Protection

Adding an isolated comparator such as a single threshold comparator AMC23C11 for OC detection ensures appropriate detection and protection of power circuits from these three conditions. The dual-threshold version (AMC23C14) can achieve both short circuit and overload protection.

As there is no need for a power supply on DC+ other than for an isolated comparator, a simple, low-cost, and low BOM implementation is critical.