Circuit breakers are designed to protect an electrical circuit from damage caused by excess current from an overload or short circuit. If a circuit breaker detects such a fault, it switches automatically off to interrupt the current flow.
The most used ones are the thermal magnetic circuit breakers. They have two different tripping (switch-off) mechanisms:
1) Magnetic tripping: Fast tripping caused by large peak-currents. Only current dependent. Used for short-circuit protection.
2) Thermal tripping: Slow tripping caused by temperature rise, responding to less extreme but longer-term over-current conditions. Current and time dependent. Used for protection against overload.
Combining the thermal and magnetic tripping results in the overall time-current tripping curves. The circuit breaker must be chosen adequately, based on expected peak-loads and average loads of the application, which both must pass and not trip the circuit breaker. At the same time a disconnection must be ensured in the event an overload or short-circuit event.
Please refer the circuit breaker recommendation in the intreXis DC-DC Converter product datasheet.