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

Abstract

In this paper we demonstrate that a proper connection of two or more low cost, low accuracy DA converter can be used for the realization of a high accuracy static analog memory (SAM), that is a circuit that behaves as a high accuracy sample & hold block with infinite hold capability. The topology we propose can be applied both at board level and an integrated circuit level when designing compact and low cost devices for automated test equipment (ATE). 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 approach we propose can therefore be considered as a possible and advantageous alternative to the conventional methods employed for the realization of high accuracy, multiple outputs, programmable voltage or current sources. A prototype of a SAM based on the approach we propose has been realized and tested. As it will be shown, the experimental results we have obtained fully confirm the validity of our approach.