High speed CMOS digital-to-analog converter with linear interpolator

In this paper we propose a kind of digital-to-analog converter (DAC) with a linear interpolator, which improves 8-bit digital signal to 12-bit data, s o the resolution increases 16 times than that of DAC without interpolation. Interpolating digital-to-analog converter (IDAC) can be used to improve th e performance of DACs. IDAC technology increases the resolution of DACs and makes the output waveform of the converted analog signal much smoother tha n that of the original signal. The output analog signal has smaller distort ion and much better property than that of DAC with low pass filter. The out put speed of IDAC is about 600MHz and the resolution in digital part is 12- bit for interpolating performance and IO-bit for DAC converting operation. The chip is fabricated by 0.8 mu double-metal single poly CMOS technology. The active size of chip is 1x1mm(2). Power dissipation is 60mWatts at suppl y 5v. The error of IDAC converting result is about 10 times better than tha t of DAC without interpolator. SNDR of IDAC is 68dB.