PN junctions and diodes

What is the main role of ESD protection diodes connected to the input/output pins of an IC?

  1. ATo divert excessive voltages such as static discharge to the supply or ground and protect internal circuits
  2. BTo increase pin capacitance and speed up signals
  3. CTo amplify signals
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Answer: A. To divert excessive voltages such as static discharge to the supply or ground and protect internal circuits

Electrostatic discharge (ESD) from people or equipment can reach thousands of volts. With diodes between the I/O pins and the supply and ground, the diodes conduct when an excessive voltage appears and divert the current, preventing damage to internal circuits such as gate oxides.

  • A. Correct. They divert excessive voltages to protect internal circuits.
  • B. Their capacitance actually slows signals, so it is designed to be small.
  • C. ESD protection diodes do not amplify.
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More PN junctions and diodes questions

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