| 摘要 |
PURPOSE:To obtain a CMOS-IC provided with an output terminal having a large rupture-resistance strength against surge by forming a drain region serving as the output terminal in extension and thereby giving a resisting component to the drain region. CONSTITUTION:P-N channel MOS transistors Tr1 and Tr2 are connected in series between power sources, with a gate made to be an input terminal. A resistor is formed by forming the drain region of the MOS transistors Tr1 and Tr2 slenderly and connection to the output terminal 1 is made through the intermediary of resistors R1 amd R2. PN junction formed between the drain and a substrate is made to be protection diodes D1 and D2. When surge voltage is impressed, the diodes D1 and D2 turn conductive and the voltage is also applied to the resistors R1 and R2. However, a time constant circuit is formed by a capacity component formed with the substrate and the voltage made gentle is thus applied to the drain, whereby the breakdown of the transistors is prevented. |
