SEMICONDUCTOR DEVICE WITH NORMALLY OPERATED SURGE PROTECTION CIRCUIT

摘要

PURPOSE: A semiconductor device is provided to operate normally a surge protection circuit by forming differently the first and second npn transistors. CONSTITUTION: A surge protection circuit(51) is electrically connected to a signal input terminal(34). The surge protection circuit includes a first transistor(32) and a second transistor(33). The first and second transistors include first and second bases, respectively. The narrowest region of the first base has a different width from that of the second base, so that the first transistor is more apt to reach breakdown than the second transistor.