| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an electron element for separating a short-circuit portion speedily and certainly, by dividing the element having many emitters as a plurality of blocks, and electrically separating a short-circuit block by an active element that automatically suppresses current during a short circuit between an emitter and a gate. SOLUTION: A portion sandwiched by two island-like p-type regions 52 forms a so called joint field-effect transistor(JFET), and an electrode 59 forms a short- circuit state between a source electrode and a gate electrode of the JFET. A voltage of a drain equals to a supply voltage and a source voltage during a short circuit between an emitter and a gate is null, so that saturated current flows. During normal operation only a slight part of an emitter current flows as a gate current, so that the source voltage decreases slightly than the supply voltage. The saturated current can be decreased by shortening a gap between the p-type regions 52 and increasing the length in the current flow direction to electrically separate a short-circuit block.</p> |
