PIASTRINA CON CIRCUITO INTEGRATO A SEMICONDUTTORE AVENTE UN CIRCUITO DI IDENTIFICAZIONE

摘要

The semiconductor integrated circuit chip has an identification circuit connected between any one of the power voltage supply terminals and any one of the input terminals. The identification circuit comprises a voltage limiter having a predetermined limiting voltage level for limiting the input potential difference between the power voltage supply terminal and the input terminal, and an option unit connected in series with the voltage limiter for determining the identification information of the chip according to whether or not a current path is formed during the manufacturing process of the chip. - The voltage limiter comprises a set of serially connected MOS transistors whose respective gates are connected to the drains thereof. The predetermine limiting voltage level is set to be the sum of the threshold voltages of said MOS transistors. The option unit consists of a fuse connection or disconnection of which is obtained during the manufacturing process of the chip.