SEMICONDUCTOR INTEGRATED CIRCUIT

PROBLEM TO BE SOLVED: To achieve a semiconductor integrated circuit reinforced against electrostatic breakdown. SOLUTION: In a separated power supply cell X', the cathode of a first diode 15 is connected with a power supply line 6A, the cathode of a second diode 16 is connected with a power supply line 6B, and the anodes of first and second diodes 15 and 16 are connected in common. A bypass line 20 is connected, at one end thereof, with the anodes of the first and second diodes and connected, at the other end thereof, with a power supply ring 7 supplying required power to the internal circuit 3. Since an abnormal potential occurring on the power supply line 6B, for example, due to noise, or the like, escapes to the power supply ring 7 through the second diode 16 and the bypass line 20, electrostatic breakdown in an IO circuit 2B can be avoided. COPYRIGHT: (C)2007,JPO&INPIT