Analog test signal generation on a digital tester

This paper presents an alternative approach for the generation of analog test signals to accommodate test and verification of mixed signal ICs requiring analog input stimuli. In contrast to the conventional approach whereby analog test requirements are met using hardware added to the digital test-environment, the proposed technique relies on a digital tester for supplying analog test signals to the DUT. This can be accomplished by using oversampling and noise shaping techniques (sigma-delta modulation) in combination with the digital tester as a high speed source of digital signals, and simple low-pass filtering. A concise general outline of the technique is presented followed by experimental results to validate the approach. Some observed and anticipated difficulties are discussed