The embodiment of the invention discloses a
bus voltage sampling circuit and a power supply
system, and the circuit comprises a high-
voltage sampling unit which is used for sampling a
DC bus voltage and outputting a first voltage
signal, and is connected with a first controller; the
signal conversion unit is used for converting the first voltage
signal into a current signal and outputting the current signal, and is connected with the output end of the high-voltage sampling unit; and the
signal restoration unit responds to the current signal to output a second voltage signal, is connected with the output end of the voltage-controlled
current source, and is also connected with the second controller. According to the embodiment of the invention, the
direct current bus voltage of the first controller is converted into the current signal, then the current signal is restored into the voltage signal, and the voltage signal is input to the second controller, so that many mismatching problems of front and rear controllers are solved, and sampling of the
direct current bus voltage is completed by one sampling circuit; the
power consumption, the hardware cost and the PCB area caused by an extra sampling circuit can be avoided.