| 摘要 |
PURPOSE:To obtain an input protecting device by utilizing the threshold voltage of a short-channel MOSFET for clamping voltage. CONSTITUTION:The interval L between the source 116 and the drain 102 of a MOSFET 119 having a field oxide film 118 as a gate oxide film is set in the range for allowing a short-channel effect. Thus, the thicker the thickness of the gate oxide film is, the more the short-channel effect becomes to lower the threshold voltage. When the interval between the source and the drain is likewise selected suitably, the clamping voltage can be set arbitrarily lower than the gate insulating withstand voltage so as to protect the input gate. |
