| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a thyristor PROM circuit capable of preventing destruction of a trimming element due to a surge even when a common write terminal is provided extending externally and a write circuit is provided outside a chip. <P>SOLUTION: At the common write terminal PE, a surge protection circuit 23 is provided which comprises a thyristor 5 for protection against a surge, a diode 9 for protection against a surge, and an N-channel MOS transistor 8 for switching OFF a thyristor 2 that is a switching element when a surge is applied. A surge current applied through the common write terminal PE is caused to flow through the surge protection thyristor 5 when a power supply voltage is open. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
