Leakage detection chip-CN54125X

The CN54125X is a high-performance ground fault circuit interrupter (GFCI) controller used for detecting ground fault leakage paths in electrical circuits, which can detect type AC leakage currents, featuring a wide AC input voltage range (50V–380V, 50/60Hz), high input sensitivity (5mV), consistent leakage detection thresholds, a wide operating voltage range (3V–5.5V), low quiescent current, a wide operating temperature range, and strong resistance to electromagnetic interference. It is particularly suitable for Ground Fault Circuit breakers and Ground Fault Circuit relays. When a leakage current occurs in the L and N lines passing through the current transformers, the zero-sequence current transformer detects the leakage current signal. The subsequent circuitry converts this signal into a voltage signal, which is transmitted to the chip’s input. Once the peak value of the input voltage signal exceeds 5 mV, the chip’s output pin generates a high-level signal lasting for at least 20 ms to ensure the external SCR conducts. The CN54125X integrates functional modules such as a regulated power supply, amplification circuit, comparison circuit, trip controller and trip driver circuit; externally, only a current transformer and a small number of components such as resistors and capacitors are required.