5.14 Overcurrent Protection

The MCP16367/8/9 provides instantaneous cycle-by-cycle current limiting by sensing the current through the high-side switch.

Leading edge blanking is implemented on the high-side switch to prevent false triggering of the overcurrent limit.

The device also incorporates frequency fold-back and advanced overcurrent protection features. During prolonged overloads or short-circuit conditions, future switching pulses are inhibited to protect the device and external components. Specifically, if an overcurrent event is detected during a sustained overload at high input voltages, the next three switching pulses are inhibited, allowing the inductor current to decrease to safer levels.

Additionally, if the feedback voltage decreases, the switching frequency will also decrease as low as 200 kHz.