I am currently designing a 2-layer PCB with a microcontroller and DAC over I2C at 100kHz. Can I route the I2C lines through vias in a 2-layer PCB?
Definitely. You don’t mention what else is on the board, but if you follow the standard routing guidelines (like don’t route it through your switching regulator) you should be fine!
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Yes, typically, routing a 100 kHz signal like I2C is quite forgiving. Ensure that both the SDA and SCL lines are routed similarly and kept close together to minimize potential issues.
Also, consider the I2C total capacitance limit of 400 pF, especially if the traces are exceptionally long. Exceeding this limit could lead to potential issues.
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It shouldn’t be an issue. We’ve been using Vias on I2C running up to 500 kHz without problems.
The only trouble we’ve encountered was due to a faulty via, which introduced a series resistance in the I2C line. This significantly impacted the board’s slew rate, causing I2C communication failure. However, this was observed only on a prototype board and has not occurred on any production boards thus far.
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