Circuit and method for stably outputting analog voltage and current signals

The invention discloses a circuit and method for stably outputting analog voltage and current signals. The circuit comprises a micro-control unit, a digital-to-analog conversion circuit, an MCU reset detection circuit and a three-state gate buffer U4G. The working voltage of the micro-control unit is monitored in real time through the MCU reset detection circuit, and when the working voltage of the micro-control unit is lower than a preset threshold value of the MCU reset detection circuit, the MCU reset detection circuit outputs a control level, so that the three-state gate buffer U4G outputs a high resistance state; therefore, unreliable analog voltage and current signals output by the micro-control unit in the under-voltage reset process are prohibited, and the reliability of the analog voltage and current signals output by the micro-control unit is ensured; when the enable end of the three-state gate buffer U4G does not receive the control level, the three-state gate buffer U4G shapes the signal input by