In this paper, we propose a 12-bit 100-MHz current-steering digital-to-analog converter (DAC) for system-on-a-chip (SOC) applications. We adapt the segmented architecture to design this DAC to obtain better performances of LVL, Glitch energy, and monotonicity. The segmented architecture includes 7- MSBs which are decoded into 127 equally weighted current sources and 5-LSBs which are corresponding to binary-weighted current sources. Based on the TSMC 0.35um 2p4m CMOS technology, we use HSPICE to simulate the proposed DAC. The simulation results show that the proposed DAC has the following characteristics: INL < ±0.4LSB, DNL < ±0.25LSB, and settling time less than 9ns. The proposed converter?s spurious free dynamic ranges (SFDfi) for are larger than 80 dB and 65 dB at an update rate (f_clk) lOOMHz and its output frequencies are I MHz and 49 MHz, respectively. The power consumption is 47 m W at the maximum conversion rate.