Design and realization of high-accuracy static analog memories (SAMs) using low-cost DA converters

In this paper, the authors demonstrate that a proper connection of two or more low-cost low-accuracy digital-analog converters can be used for the realization of a high-accuracy static analog memory (SAM). High-accuracy SAM is a circuit behaving as a high-accuracy sample and hold block with indefinite hold capability. The proposed topology can be applied both at the board level and at the integrated-circuit level when designing compact and low-cost devices for automated test equipment. In fact, as it will be demonstrated in this paper, high accuracy can be guaranteed by design, without the need for any calibration procedure. The proposed approach can therefore be considered as a possible and advantageous alternative to the conventional methods employed for the realization of high-accuracy multiple-output programmable voltage or current sources. A prototype of the SAM, based on the proposed approach, has been assembled and tested. As it will be shown, the obtained experimental results fully confirm the validity of the approach.