General-purpose logic IC is strong enough to withstand electrostatic discharge (EDS) standard. However, if static electricity of a greater intensity is applied to it, malfunction or damage may occur.
Because the oxide film at the input gate of a general-purpose logic IC is very thin (hundreds to thousands of angstroms), it could be damaged by an ESD of hundreds to thousands of volts.
To prevent ESD-induced damage, each input pin of Toshiba’s general-purpose logic ICs incorporates an ESD protection circuit. However, the internal ESD protection circuit has a limit.Therefore, inputs that might be exposed to excessive ESD (e.g., inputs connected to the external interface of a board) require ESD protection diodes to increase ESD protection capability. (Fig. 1)
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