||With the continuous development of technology, mobile communication device has more and more demand for function, with the widespread use of smartphones and, increasingly, APP needs, whether in power saving or high speed or high precision even small area is the trend of present digital-to-analog converter circuit design. Therefore, this thesis proposes a new specify code for the decoder architecture. Grouping and Coding are two ways to reduce the switching of the current cell. It adapts a segmented current-steering architecture combining with the thermometer code. The segmented current steering architecture that comprises 6MSB’s thermometer code and 6LSB’s specified code is used, they combine the advantages of the specified code digital-to-analog converter’s small area, low-power and static specification and thermometer code digital-to-analog converter’s dynamic performance. Compare with traditional 8MSB’s thermometer code digital-to-analog converter and 4LSB’s binary-weighted digital-to-analog converter, due to the reduce of the 192 current cell, the chip area is much more small. Considering the performance, the power consumption, and the chip area, a new digital to analog converter is proposed. |
The design is designed in TSMC 90nm CMOS process. The sampling rate and resolution of the DAC are 1GS/s and 12-bit, respectively. The power consumption is 24.3mW. The simulation results show that the proposed specified code DAC can achieve high precision and reduce the chip area by adapting the proposed specified code.
Key words: digital-to-analog converter, high speed, high precision, small area, the specified code.