The Current Mirror Thermal Characterization Method and its Implementation in a Power SOI BJT Process

摘要

A new current mirror method is described that can be used to evaluate thermal issues in silicon-on-insulator (SOI) bipolar junction transistors (BJTs). This method is compared to conventional transistor level techniques and is shown to significantly improve safe operating area (SOA) measurement sensitivity. Unlike conventional methods, the current mirror method can provide quantitative analysis of the BJT's thermal instability over a wide power range, even in the apparent SOA of the device. Also, this method can predict and evaluate SOA with respect to emitter ballast resistance and current crowding.