A 12-bit 1 GS/s Current Steering DAC with the Appointed and Thermometer Coding Scheme

Abstract

A novel appointed code for the decoder architecture of digital to analog converter is proposed by grouping and coding the current cell of the DAC's output to reduce further glitching of the current cell. In addition, the segmented current-steering DAC topology combines 6-MSB thermometers with 6 LSB of the appointed coding scheme. The proposed appointed code DAC's advantages exhibit a smaller area, lower power, and better static performance. On the other hand, better dynamic performance can achieve by implementing the thermometer code. The proposed 12-bit DAC utilizes the TSMC 90nm process with 1V/1.2V supply voltage and a sampling rate of 1.2 GS/s. The simulated DNL and INL are 0.12 LSB and 0.09 LSB, respectively. The proposed appointed code with thermometer code segmented DAC achieves higher output precision and less die area.