1 Background

Fault-detection mechanisms are a necessity in high-power industrial systems such as motor drives and solar inverters, as well as automotive systems including electric vehicle (EV) chargers, traction inverters, onboard chargers and DC/DC converters. DC bus-based overcurrent protection is widely used in electric motor drives. The traditional implementation of overcurrent (OC) fault detection is discrete with a combination of non-isolated multichannel comparators and either optocouplers or digital isolators. To meet the growing needs of fault detection, TI is introducing a new family of basic and reinforced isolated comparators to the TI isolation portfolio. The primary use case is ultra-fast overcurrent, overvoltage, over temperature detection in high-voltage industrial and automotive HEV/EV systems. Its smaller PCB area is particularly suitable for applications with miniaturization and high-power density needs. Compared with traditional solutions, it has significant advantages in CMTI, response time, threshold accuracy, hysteresis, and latching function.

The power supply on DC+ for overcurrent protection can be generating by either adding a transformer or adding an additional secondary winding to an existing transformer. However, technical challenges such as transformer size limitations or the proximity of these transformers to the actual OC implementation will practically limit such a transformer-based implementation.