AN ELECTRICAL TECHNIQUE FOR MEASURING THE T_(ch) OF GaAs MESFETS UNDER NORMAL OPERATING CONDITIONS

摘要

In this paper, an electrical technique is proposed for measuring the channel temperature (T_(ch)) of GaAs MESFETs under normal operation conditions. The fundamental of this technique is the temperature sensitive electrical parameter (TSEP). On the basis of TSEP, a first PC controlled equipment has been developed. In this equipment, a high speed switch circuit is made to convert the status of the device under test from the normal operation states into measuring states. The value of T_(ch) measured by this equipment is about 5% higher than the peak channel temperature obtained from the infrared thermal image at the same conditions. The equipment reported in this paper can provide convenience not only for GaAs MESFETs manufactures in evaluating device thermal behavior and conducting reliability screening, but also for package manufactures in evaluating package thermal characteristics.