| 摘要 |
PROBLEM TO BE SOLVED: To provide an electrostatic discharge protective circuit which protects a protection object circuit formed with an N-channel MOS transistor from an electrostatic discharge phenomenon. SOLUTION: This electrostatic discharge protective circuit protects an internal circuit having the N-channel MOS transistor connected to a power terminal side, and includes: an electrostatic discharge detection circuit generating a detection pulse when electrostatic discharge occurs on a power terminal; and an electrostatic block circuit arranged between the power terminal and the N-channel MOS transistor of the internal circuit, and having a P-channel MOS transistor of which the part between the source and the drain is cut off in response to the detection pulse. The electrostatic discharge protective circuit further includes an electrostatic discharge passage circuit arranged between the electrostatic block circuit and a ground terminal, and turned on in response to the detection pulse. When electrostatic discharge occurs on the power terminal, the electrostatic block circuit cuts off charge associated with the electrostatic discharge to prevent it from flowing in the N-channel MOS transistor of the internal circuit. COPYRIGHT: (C)2009,JPO&INPIT
|
