AN IMPROVED METHOD OF GENERATING ANALOG WAVE-FORMS FROM DIGITAL DATA

As normally used, the digital-to-analog converter generates a series o f constant amplitude signals that, taken together, approximate the des ired analog equivalent of the initial digital signal. Hence, many samp les are required to generate a reasonably smooth approximation. Even s o, it is usually necessary to filter the resulting approximation to re move the sharp corners of the constant amplitude signals and blend the m together. This requirement is particularly troublesome in the case o f generating very low frequency analog signals, e.g., a 1 Hz sine wave . In this article we propose an inexpensive improvement in the commerc ial digital-to-analog converter cards. This improvement results in a w aveform with much better quality than that produced by the usual metho ds. (C) 1998 American Institute of Physics. [S0034-6748(98)02106-6]