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 the 8-bit digital signal to 12-bit data, so the resolution increases 16 times than that of a DAC without interpolation. The interpolating digital-to-analog converter (IDAC) can be used to improve the performance of DACs. IDAC technology increases the resolution of DACs and makes the output waveform of the converted analog signal much smoother than that of the original signal. The output analog signal has smaller distortion and much better property than that of DAC with low pass filter. The output speed of IDAC is about 600 MHz and the resolution in the digital part is 12-bit for interpolating performance and 10-bit for DAC converting operation. The chip is fabricated by 0.8 μ double-metal single poly CMOS technology. The active size of chip is 1×1 mm². Power dissipation is 60 mW at supply 5 V. The error of the IDAC converting result is about 10 times better than that of DAC without an interpolator. The SNDR of IDAC is 68 dB