| 摘要 |
PURPOSE:To detect the excessive surge of static electricity and the like and to enable to directly evaluate the electrostatic environment in the process in which MOSIC is used by a method wherein an erasable element exclusively used for read-out, having the electric pulse width of 1,000 nanoseconds or below necessary for write-in operation, is used. CONSTITUTION:When static electricity of negative voltage when compared with a power source terminal VDD is applied to the drain terminal VDD of an EPROM element from the outside of a package which envelopes an electrostatic circuit, electrons are injected into the floating gate 201 of the EPROM element 2 by a drain-avalanche phenomenon, and the gate 201 is negatively electrified. At this time, the gate 401 of a PchrTr 4 electrically connected to the gate 201 is also negative electrified, but the PchTr 4 is brought into a conductive state when the quantity of the above-mentioned electrified charge is sufficient. As a result, when the prescribed voltage is added to the power source terminal VDD and VSS and a signal is inputted to the gate terminal 301 of a Pch-Tr 3, an inverted wave form is outputted to a buffer output 601, and the fact that sufficient charge is accumulated by static electricity can be confirmed. |
