Analog-to-digital conversion system of scale

The utility model provides an analog-to-digital conversion system of a scale. The system comprises a single chip microcomputer and the like. A first resistor and a second resistor are connected between a weighing sensor and a the analog-to-digital conversion chip, a third resistor is connected between the first resistor and the second resistor, the single chip microcomputer is connected to the analog-to-digital conversion chip, a fourth capacitor, a fifteen resistor and a sixteen resistor are connected in series in order, the fourth capacitor is connected with the weighing sensor, an integration switch power supply voltage stabilization chip is in parallel with the sixteen resistor, the weighing sensor is connected with a positive excitation power supply and a negative excitation power supply, and the voltage of the positive excitation power supply is different from the voltage of the negative excitation power supply. According to the analog-to-digital conversion system of the scale, the output mode of the positive/negative excitation voltage of the scale is changed, a high excitation voltage of a sensor can be output, and a low common mode voltage satisfying the sigma-delta ADC can be achieved, and the cost and the difficulty of design for raising the adaptive capacity of the scale on the site can be reduced.