| 摘要 |
PURPOSE:To improve further the dielectric strength of an LDD structure transistor (TR) by connecting a collector of a surge protection TR to an output node and inserting the surge protection resistor between the output node and one end of the side of output node of the LDD structure TR. CONSTITUTION:Even when a high voltage is impressed momentarily to an external output terminal 14, since resistors 16, 17 act like a current limit circuit, no over voltage/current is impressed to the LDD structure TRs 11, 12 and they are protected. The discharge of the electric charge when a surge is impressed to the external output terminal 14 is retarded in comparison without the resistors 16, 17 because of the existence of the resistors 16, 17 but the discharge is executed quickly by a protection TR 15 made of a parasitic bipolar TR having immunity against the surge. That is, the surge proof of the LDD structure MOS TR is improved against the surge input from the external output terminal 14 is improved by the resistors 16, 17. |
