Chaotic signal generating circuit

The invention relates to a chaotic signal generating circuit, comprising a microcontroller, a signal isolating circuit, three D/A switching circuits; each D/A switching circuit comprises 16-bit shift registers and 16-bit DAC registers and shift registers in each D/A switching circuit are connected in series to form a 48-bit shift register. Serial digital signals output by an SPI interface of the microcontroller are transmitted to a serial data input terminal of a first D/A switching circuit through the signal isolating circuit; clock signals and latch control signals output by the SPI interface are respectively transmitted to a clock input terminal and a latch control signal input terminal of the D/A switching circuit through the signal isolating circuit. In the invention, based on the chaotic circuit of the microcontroller, the Euler algorithm is adopted to carry out discretization processing on the continuous state equation of the improved generalized Lorenz system; as a result, the operation algorithm which can be appropriately realized by the microcontroller is established and folding directions of chaotic attractors and system operation modes are optional.