A Low-Cost Data Acquisition System Design for Multifunctional Test Equipment in Electronics Laboratories

Abstract

There are various commercially available multifunctional electronics laboratory test equipment on the market that integrates an oscilloscope, signal generator, and logic analyzer. The price point for all these devices typically exceeds USD 250. To lower this cost to around USD 100, the data acquisition components of these devices need to be re-evaluated. In this paper, we present the design of an analog front-end (AFE) for low-cost multifunctional laboratory equipment, mainly for electronics students. The primary objective was to meet student requirements while ensuring minimal cost, maximum functionality, and high robustness. Through our research, we optimized our AFE design to achieve these objectives effectively. Our approach addresses key limitations found in existing designs, as we developed four-stage attenuation and three-stage op-amp gain architecture. This arrangement optimizes signal clarity and achieves high bandwidth while maintaining a cost-effective framework suitable for educational applications. With this study, a 20 MHz bandwidth, +/- 40 V input voltage range, volt/div range from 5 mV to 10 V, and minimum amplitude resolution of 9.7 mu V were achieved in the design of the analog front-end and data acquisition unit. The achieved bandwidth and linearity enable designed AFE to accommodate applications such as ultrasonic discrete TGC (Time Gain Compensation).