Protection against transient overvoltage in precision AC-DC transfer measurement system

摘要

Reduction in size and improvement of sensitive margins in modern semiconductor devices make them increasingly susceptible to stress and subsequent damage caused by the overvoltage. A fast responding and a higher energy absorbing overvoltage protection is desired. A hybrid solution is proposed. A moderate energy absorbing device is connected in parallel with a fast responding device to complement each other. Nonlinear current-voltage (IV) characteristics of these devices enable them to least interfere with the performance of the precision ac measurement system while reducing the effects of transient overvoltage. In this paper, the causes of transient overvoltage in ac-dc measurement system are analysed and a hybrid voltage limiting solution is proposed.