| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor integrated circuit operable on a plurality of systems of power supplies which has an input circuit constructed by a standard CMOS process.SOLUTION: A P channel transistor 1 and an N channel transistor 2 comprising 1.2 V standard transistors, respectively, are interposed in series between a first power supply node (voltage VCC=1.2 V) and a second power supply node (voltage VSS=0 V), and a common connection node of respective drains is an output node for a signal OUT to be fed to an internal circuit. A gate of the P channel transistor 1 is directly fed with an external signal EXIN having an amplitude of 3 V. A gate of the N channel transistor 2 is, on the other hand, fed with the external signal EXIN via an N channel transistor 3 of single-sided high voltage structure and connected with a drain of an N channel transistor 4 having a gate and a source connected to the second power supply node. |
