中文摘要：

A 2.5 GS/s 14-bit D/A converter(DAC) with 8 to 1 MUX is presented. This 14-bit DAC uses a "5+9"segment PMOS current-steering architecture. A bias circuit which ensures the PMOS current source obtains a larger output impedance under every PVT(process, source voltage and temperature) corner is also presented. The8 to 1 MUX has a 3 stage structure, and a proper timing sequence is designed to ensure reliable data synthesis. A DEM function which is merged with a "5-31"decoder is used to improve the DAC’s dynamic performance. This DAC is embedded in a 2.5 GHz direct digital frequency synthesizer(DDS) chip, and is implemented in a 0.18 m CMOS technology, occupies 4.86 2. 28 mm~2 including bond pads(DAC only), and the measured performance is SFDR > 40 d B(with and without DEM) for output signal frequency up to 1 GHz. Compared with other present published DACs with a non-analog-resample structure(means return-to-zero or quad-switch structure is unutilized),this paper DAC’s clock frequency(2.5 GHz) and higher output frequency SFDR(> 40 d B, up to 1 GHz) has some competition.

英文摘要：

A 2.5 GS/s 14-bit D/A converter（DAC） with 8 to 1 MUX is presented. This 14-bit DAC uses a ＂5＋9＂segment PMOS current-steering architecture. A bias circuit which ensures the PMOS current source obtains a larger output impedance under every PVT（process, source voltage and temperature） corner is also presented. The8 to 1 MUX has a 3 stage structure, and a proper timing sequence is designed to ensure reliable data synthesis. A DEM function which is merged with a ＂5-31＂decoder is used to improve the DAC＇s dynamic performance. This DAC is embedded in a 2.5 GHz direct digital frequency synthesizer（DDS） chip, and is implemented in a 0.18 m CMOS technology, occupies 4.86 2. 28 mm-2 including bond pads（DAC only）, and the measured performance is SFDR 〉 40 d B（with and without DEM） for output signal frequency up to 1 GHz. Compared with other present published DACs with a non-analog-resample structure（means return-to-zero or quad-switch structure is unutilized）,this paper DAC＇s clock frequency（2.5 GHz） and higher output frequency SFDR（〉 40 d B, up to 1 GHz） has some competition.