this paper introduced an 8-bit current steering CMOS digital-to-analog converter (DAC). With optimized circuit matching technique, the working frequency band varies from 10MHz to 200MHz with a spurious-free dynamic range (SFDR) attenuating from 61dB to 40dB. The measurement results of the differential nonlinearity and integral nonlinearity is 0.16LSB and 0.4LSB, respectively. The circuit is fabricated in a 0.5um single poly three-metal 5V CMOS standard process. The whole chip occupies about 2.822 mm2. When the sampling rate is 200MHz, the power consumption of the DAC is about 113mW.