| 摘要 |
PURPOSE:To prevent an output buffer circuit from the generation of latch-up by connecting a resistor element and a p-channel MOSFET formed on an n-type well area between the coupling node of a pair of n-channel MOSFETs connected in series and coupled with an external terminal and a power supply terminal. CONSTITUTION:The output buffer circuit BO has amplification stages constituted of two connected complementary MOS(CMOS) inverter circuits I1, I2 consisting of a p-channel MOSFET Q1 and an n-channel MOSFET Q2 and one CMOS inverter circuit I3 having similar constitution to said circuits I1, I2. The output stage is connected by n-channel MOSFET Q3, Q4 connected to an I/O terminal I/O. The resistor element R and the p-channel MOSFET Q5 formed in the n-type well area are connected between the coupling node N of the FETs Q3, Q4 and the power supply terminal VCC to prevent the generation of latch-up for making abnormal current flow into the power supply terminal and the connection terminal. |
