| 摘要 |
PURPOSE:To prevent an input limiting resistor from blowing out as well as the terminal breakdown of input protective diode from occuring by a method wherein, within an MOS integrated circuit device with input protective diode, power consumption is divided by transistors formed between the input protective diode and a power supply or ground terminals. CONSTITUTION:An N<+> diffused region 22 is formed on a P-type well region 21 to form an N diode 14 connected to an input terminal 1. The P-type well region 21 is impressed with the voltage of ground terminal GND through P<+> diffused regions 23 to form N<+> diffused regions 2 likewise impressed with the voltage of ground terminal GND adjoining the P<+> diffused regions 23. Besides, an NPN transistor 4 is formed between N<+> diffused regions 22 and 24 while another NPN transistor 3 is formed between diffused regions 22 and 2. When the input terminal 1 is impressed with (-) surge and a current from a power supply Vcc flows to the input terminal 1 through the NPN transistor 4, the power consumption between collector and emitter of the NPN transistor 4 is divided into those between collector and emitter of the NPN transistors 3 and 4 to prevent the thermal breakdown of an input protective resistor and the N diode 14 from occuring. |
