Discrete KNX communication circuit

The utility model discloses a discrete KNX communication circuit, which comprises a power supply circuit, a CPU power supply circuit, a voltage-dividing current-limiting circuit, a signal transmitting circuit and a signal receiving circuit, and is characterized in that the power supply circuit generates a 5V power supply for supplying power to other circuits, the CPU power supply circuit generates a 3.3 V power supply for supplying power to a CPU, an external communication system P1 is connected with an inductor L1, the inductor L1 is connected with a bidirectional diode V2, and the bidirectional diode V2 is connected with a voltage-dividing current-limiting circuit. The bidirectional diode V2 is respectively connected with the power supply circuit, the signal receiving circuit and the voltage-dividing current-limiting circuit, the voltage-dividing current-limiting circuit is connected with the signal transmitting circuit, the signal receiving circuit shapes a signal of an external communication system P1 and