ELECTROSTATIC DISCHARGE(ESD) PROTECTION CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide an ESD protection circuit to remain non-conductive until an input voltage reaches a prescribed level other than the power supply range of the circuit. SOLUTION: An ESD protection circuit 60 includes diodes reversely connected in series between a signal input terminal and the power supply terminal of a protected circuit. Thereby an input signal can be raised up to a selected level so as to reach an applied voltage without triggering the circuit 60. The circuit 60 can be produced as an integrated circuit provided with a diode including a pair of P+ areas in an N-well or including an individual P+ area forming a PN junction part with an individual N-well. The diode may be formed on a polysilicon layer in a field oxide area. It is also possible to connect a 2nd pair of reversely connected diodes between the signal input terminal and a ground terminal.