Co-grounded multi-path circuit for outputting 4-20mA of current signals

The invention discloses a co-grounded multi-path circuit for outputting 4-20mA of current signals. The co-grounded multi-path circuit comprises a sampling module, an MCU (Microprogrammed Control Unit) module, a PWM (Pulse-Width Modulation) module, a filtering module and a V/I (Voltage/Current) conversion module, wherein the sampling module is used for filtering an input voltage signal and transmitting the filtered input voltage signal to the MCU module, the MCU module is used for performing calculation on the input voltage signal transmitted by the sampling module to obtain a control value; the PWM module is used for generating PWM waveforms corresponding to the MCU control value; the filtering module is used for converting the voltage signal processed by the PWM module into a direct-current voltage; and the V/I conversion module is used for converting the direct-current voltage processed by the filtering module into 4-20mA current signals to be output, PWM output and RC (Resistor-Capacitor) filtering are used for realizing digital-to-analog conversion, using expensive special digital-to-analog conversion chips are avoided, and 12-bit precision is realized as well. The V/I conversion module not only realizes current output, but also can make multi-path current signals share the same reference ground; and the circuit has the advantages of skillful design, fewer devices and parts, lower cost and suitability for popularization and application.