Gain control circuit, method and vehicle

The invention relates to a gain control circuit and method and a vehicle, and relates to the technical field of circuits, the gain control circuit comprises a current detection resistor, an operation amplification unit, an analog-to-digital conversion unit and a gain control unit, the input end of the operation amplification unit is connected to the two ends of the current detection resistor, and the output end of the operation amplification unit is connected with the input end of the analog-to-digital conversion unit; the output end of the analog-to-digital conversion unit is connected with the input end of the gain control unit, and the output end of the gain control unit is connected with the input end of the operational amplification unit. And the operational amplification unit is used for collecting voltage signals at the two ends of the current detection resistor and carrying out amplification processing on the voltage signals based on the voltage gain gear to obtain analog voltage signals. And the analog-to-digital conversion unit performs analog-to-digital conversion on the analog voltage signal to obtain a digital voltage signal. And the gain control unit is used for controlling the gain gear of the operational amplification unit according to the digital voltage signal and the voltage gain gear. Therefore, the gain gear of the operational amplification unit can be flexibly controlled.