Negative pressure tracking device

The utility model belongs to the technical field of instrument measurement, and particularly relates to a negative voltage tracking device, which is characterized in that a first voltage sampling circuit is connected with the output end of a first analog channel; the second voltage sampling circuit is connected with the output end of the second analog channel; the inverting input end of the processing module obtains a voltage sampling signal according to the values of the positive electrode output signal and the first negative electrode output signal, and the in-phase input end of the processing module is connected with the output end of the second analog channel; the feedback output circuit is used for controlling conduction or cut-off according to a processing result of the processing module; by arranging the first voltage sampling circuit, the second voltage sampling circuit, the processing module and the feedback output circuit, when the load is dynamically adjusted, the power supply voltage output amplit