Adding circuit for multi-channel signals and implementation method of adding circuit for multi-channel signals

An adding circuit for multi-channel signals, comprising:

• an operational amplifier, which is provided with a first input terminal and a second input terminal having an equal voltage in a steady state, wherein the first input terminal is connected to a reference ground;
• a plurality of charge and discharge circuits, which are connected between the reference ground and the second input terminal of the operational amplifier, wherein the charge and discharge circuit is operable to be charged via a connected reference voltage and then discharge electrical charges in each clock cycle when the charge and discharge circuit itself is in a working state;
• a charge transfer circuit, which is connected between an output terminal and the second input terminal of the operational amplifier and operable to discharge electrical charges and then be charged via the electrical charges discharged by all the charge and discharge circuits which are currently in the working state in each clock cycle when the charge transfer circuit itself is in a working state;
• a switch sequence, which includes a plurality of switches distributed in the plurality of charge and discharge circuits and the charge transfer circuit, and is operable to control a state of each of the plurality of charge and discharge circuits and a state of the charge transfer circuit to be or not to be the working state in each clock cycle by changing a switch state of the switch sequence;
• a control circuit, which is operable to calculate a number of the clock cycle in which the plurality of charge and discharge circuits and the charge transfer circuit are respectively in the working state during one integration cycle, based on the integration cycle and a duty cycle respectively preset for the plurality of charge and discharge circuits and the charge transfer circuit;
• to control an actual number of the clock cycle in which the plurality of charge and discharge circuits and the charge transfer circuit are respectively in the working state during one integration cycle to be equal to the calculated number via controlling a state of each switch in the switch sequence;
• and to determine an adding result according to a voltage at the output terminal of the operational amplifier in at least one integration cycle, wherein, the integration cycle is composed of a plurality of the clock cycles;
• wherein each of the charge and discharge circuit and the charge transfer circuit includes at least one charge and discharge capacitor respectively.