Abstract: A surge protection circuit including a first MOSFET and a second MOSFET connected in series. The drain of the first MOSFET is connected to the input terminal and the source of the second MOSFET is grounded. The gate of the second MOSFET is grounded, whereas the gate of the first MOSFET is connected to a high potential power supply terminal. This makes it possible to equalize the voltages applied to the two MOSFETs constituting the surge protection circuit, and weakens the intensity of the internal electric field of respective MOSFETs, thereby prolonging the lifetime of the surge protection circuit. The surge protection circuit is particularly effective in a SOI LSI.

Abstract: A diamond-coated tungsten carbide-base sintered hard alloy material for inserts of cutting tools, which has greatly improved bond strength or degree of bonding of the diamond coating layer to the matrix and therefore is capable of exhibiting excellent cutting performance over a long period of time.The sintered hard alloy material comprises:(1) a matrix of a sintered hard alloy consisting essentially of 1-4 percent by weight cobalt, and the balance of tungsten carbide and inevitable impurities, the tungsten carbide having a coarse grain structure having an average grain size of 2-10 microns; and(2) a diamond coating layer formed over surfaces of the matrix by forming an etching layer over the matrix surfaces and then forming the diamond coating layer over the matrix surfaces via the etching layer by a low pressure vapor-phase synthesization method.If required, the matrix may further contain CO1-CO8 (ISO) free carbon.