Application of supply current testing to analogue circuits, towards a structural analogue test methodology

This paper describes work in progress towards the development, evaluation and validation of a structural, cost effective and quantifiable analog and mixed-signal test methodology, applicable in a production test environment and based on the application of supply current testing. To enable and support the measurements at first an analog supply current monitor was realised. The monitor offers a measurement range of 50 mA, a bandwidth of 1.5 MHz and a resolution better than 1 /spl mu/A. Subsequently the monitor was used to carry out measurements on a mixed-signal Asynchronous Digital Subscriber Line (ADSL) ASIC, to evaluate the feasibility of the methodology. As these initial measurements provided very interesting results, the experiments towards the validation and quantification of the test methodology are now being repeated on a larger scale. The results gathered so far show the potential of the approach to enhance test quality combined with test cost reduction.