Research of Segmented 8bit Voltage-Mode R-2R Ladder DAC

Random mismatch errors in the resistor networks are one of the dominant nonlinearity sources for high resolution and high accuracy resistor DACs. This paper applies the theory of ordered element matching in a high resolution segmented R-2R DAC. It can achieve high matching accuracy by regrouping the resistors in the MSB array according to their resistance ranks obtained by the INL test. The implementation only requires adding some additional digital circuits to the typical design. A behavioral model of 18-bit segmented R-2R DAC is created in MATLAB. The statistical results show a significant resistor area reduction compared with state of the art.