Signal generation using periodic single and multi-bit sigma-delta modulated streams

Abstract

This paper describes a new method to generate analog signals with high precision at very low hardware complexity. This method consists in reproducing periodically a recorded portion of the bitstream output of a sigma-delta modulate. This technique utilizes less hardware than conventional frequency synthesis methods and does not require a multi-bit DAC. However when a multi-bit DAC is already available, the technique can be used to increase the quality of the signal in the frequency band of interest using existing hardware. The paper demonstrates how this method can be used to generate signals for Built-in Self-Test and standard Analog and Mixed-Signal Test. Experimental results illustrating the design simplicity and low overhead are given.