A low-power, high-speed 10-bit GaAs DAC

A 10-bit digital-to-analog converter (DAC) has been designed and fabricated in gallium arsenide using a 0.7- mu m MESFET self-aligned gate process. This circuit has the highest reported resolution for a GaAs DAC with monolithic current sources. The DAC operates at a 1-GHz sampling rate while dissipating only 139 mW of power. This design is not ideal for a system-level insertion because of the required bias adjustments of the FET current source, even though the R-2R ladder required no adjustment. However, the incorporation of the R-2R ladders in a segmented approach is expected to eliminate the bias adjustment requirement.<
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