Digital-to-analog conversion circuit based on r-2r ladder resistor network architecture

A digital-to-analog conversion circuit based on an R-2R ladder resistor network architecture, wherein the digital-to-analog conversion circuit comprises:

• branch resistors, branch switches, bridge resistors, a first compensation resistor, a second compensation resistor and third compensation resistors;
• the branch resistors and the branch switches are sequentially connected in series in each branch;
• from a lowest branch to a highest branch, one bridge resistor is bridged between each two branches, a resistance of the branch resistor is equal to twice a resistance of the bridge resistor, and from the lowest branch to the highest branch, different digital signal bits are corresponded respectively;
• the first compensation resistor is serially connected to the bridge resistor between a branch of a preset bit and a lower branch adjacent to the branch of the preset bit;
• the second compensation resistor is serially connected to the bridge resistor between two lower branches adjacent to the branch of the preset bit in sequence;
• each of the bridge resistors from a branch that is two bits lower than the branch of the preset bit to the lowest branch is serially connected to one third compensation resistor, the first compensation resistor is half of the second compensation resistor, the third compensation resistor is twice of the second compensation resistor, and a resistance of the second compensation resistor is related to on-state impedance of the branch switch of the highest branch and a weight of the branch of the preset bit;
• on-state impedance of the branch switch of the branch of the preset bit is twice the resistance of the second compensation resistor;
• on-state impedance of the branch switch of a branch between the first compensation resistor and the second compensation resistor is three times the resistance of the second compensation resistor;
• on-state impedance of the branch switches of all branches, which are on a side from a branch that is two bits lower than the branch of the preset bit to the lowest branch, is equal to four times the resistance of the second compensation resistor, and on-state impedance of the branch switch of other branches is proportional to a weight of the corresponding branch.