A Multi-resolution Digital Waveform-synthesis Structure Based Multi-DAC for Arbitrary Waveform Generator

To solve the problem that arbitrary waveform generator (AWG) cannot meet both high sampling rate and high resolution in auto test system (ATS) due to the performance limitation of digital-to-analog converters (DAC), this paper proposes a reconfigurable deployment strategy based on a parallel structure of multi-DAC to implement multi-resolution AWG. In this structure, sampling rate can be increased M times by evenly dividing the waveform samples to M paths according to the phase, and resolution can be increased M times by evenly dividing the quantization codes of every waveform sample to 2
^M
paths. Furthermore, multiple DACs can be rearranged under each specific condition to make full use of the hardware resources and to balance sampling rate and resolution. In addition, we analyze the effect of the phase deviation of each DAC's sampling clock on the performance of the proposed structure. The simulation results show that a parallel structure of four DACs with sampling rate of 1GSa/s and resolution of 12-bit support three modes which are 4GSa/s-12bits, 2GSa/s-13bits and 1GSa/s-14bits; the quantization error, signal-to-noise ratio and spurious-free dynamic range is decreased with the increasing of resolution.