1. Technical Field
The various embodiments generally relate to a semiconductor integrated circuit, and more particularly, to a semiconductor integrated circuit including an electrical overstress protection circuit.
2. Related Art
An electrical overstress (EOS) phenomenon is a phenomenon in which, when a power voltage for a semiconductor integrated circuit is applied, an abnormal excessive voltage (or a spark voltage) is applied to temporarily cause an electrical discharge.
Such an EOS phenomenon may cause a circuit component failure, a circuit board failure, a triggering system failure, and the like. Also, such an EOS phenomenon may continue for a few microseconds to a few seconds.
When the EOS phenomenon is generated in an electronic circuit, a high power voltage can be applied to a line (e.g. a power line), to which a voltage is applied, for a few microseconds or more, so that thermal damage of the power line is more serious than the case of a normal electrostatic discharge (ESD) in which static electricity is transferred for a few pico-seconds.
That is to say, power lines and plugs connected to the power lines can be heated or melted by an excessive voltage applied for a long time. Therefore, demand for a protection circuit capable of effectively discharging a voltage when an excessive voltage is applied has increased.
In addition, together with such an excessive voltage, excessive power noise can be introduced, such power noise also has a problem of causing current leakage in a semiconductor integrated is circuit.