Zero Crossing Detection Chip-CN71102

The power line zero-crossing detection circuit is widely used in power carrier communication, power equipment and home appliance access switching. CN71102 is a chip dedicated to zero-crossing detection circuit. By detecting the input voltage, when the input voltage is less than the threshold, the optocoupler chip is driven to obtain the power line zero-crossing detection signal, which is provided to the application control system. When the input voltage is greater than the threshold, the output terminal presents a high impedance state. The chip itself has extremely low power consumption, and the static working current is less than 10uA, so most of the electric energy can be used to drive the optocoupler to obtain a wider zero-crossing detection pulse, making the system easier to detect. The chip input adopts a Schmitt trigger, the input low voltage VIL is as low as 0.6V, and the input high voltage VIH is as high as 2.5V. It has high detection accuracy, and the internal hysteresis processing also makes it easier for the chip to filter out the burrs on the power line, effectively preventing the erroneous zero-crossing detection signal caused by noise on the power line. The chip integrates the rectifier diode of the power supply required for the chip and the optocoupler, and the input end integrates the voltage regulator diode. Only an external capacitor is needed to power the zero-crossing detection circuit from the input end, and the overall solution requires fewer peripheral devices.