| 摘要 |
A rail clamp circuit ( 100 ) includes first and second power supply voltage rails, a multiple independent gate field effect transistor (MIGFET) ( 128 ), and an ESD event detector circuit ( 138 ). The MIGFET ( 128 ) has a source/drain path coupled between the first ( 112 ) and second ( 114 ) power supply voltage rails, and first and second gates. The ESD event detector circuit ( 138 ) is coupled between the first ( 112 ) and second ( 114 ) power supply voltage rails, and has first and second output terminals respectively coupled to the first and second gates of the MIGFET. In response to an electrostatic discharge (ESD) event between the first ( 112 ) and second ( 114 ) power supply voltage rails, the ESD event detector circuit ( 138 ) provides a voltage to the second gate to lower an absolute threshold voltage of the MIGFET ( 128 ) while providing a voltage to the first gate above the absolute threshold voltage so lowered, thereby making the MIGFET ( 128 ) conductive with relatively high conductivity.
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