Abstract: A High Electron Mobility Transistor (HEMT) device, which is formed by connecting a plurality of low power flip-chip type High Electron Mobility Transistor (HEMT) elements in parallel, or connected them in parallel and in series in combination into a tree-shaped structure, and then connecting said structure to an input terminal and an output terminal. Distances between each of the flip-chip type HEMT elements, from each element to said input terminal, and from each element to said output terminal are designed to be equal, such that powers consumed by each of the flip-chip type HEMT elements are equal, currents flowing through are evenly distributed, and heat generated is liable to be dissipated. A spike leakage protection layer, such as zinc-oxide (ZnO) amorphous layer or poly-crystal layer, is further included, hereby further enhancing the efficiency of said flip-chip type HEMT element and prolonging its service life.

Abstract: An EMP protection circuit with a counter has a surge protection circuit capable of suppressing EMP, and also use an extra counting circuit for sensing light emission or variation of magnetic force of the surge protection circuit to count the action times of the surge protection circuit, thereby warning that the surge protection circuit has reached its time-limit of use and has to be replaced. In this way, various kinds of electronic products can be more perfectly protected to avoid higher loss.