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I am reading the I2C tutorial: https://learn.sparkfun.com/tutorials/i2c/all

Why wouldn't it work without the zener diodes? What functionality are they adding? They are just there to keep the voltage at a constant level when the logic is 1 right? When the logic is 0, the transistors are on, and the zeners do more or less nothing right?

enter image description here

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up vote 5 down vote accepted

There are no actual zener diodes in there; those represent the breakdown voltage of the body diode in the MOSFETs themselves.

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