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I2C resistors

Posted: Thu Dec 28, 2023 8:06 am
by MikiMouse
i am newbie at electronic. I would like know why I need to have resistors on I2C (SDA, SCL). In some schematics are the resistors, in another are not.

Re: I2C resistors

Posted: Fri Dec 29, 2023 5:59 pm
by David
some devices connected to I2C bus have internal pull-up resistors, other have no resistors. You need to check datasheet for each device component connected to I2C. Then you need to calculate all resistor including external pull-up resistors to get a total current max. 3 mA. Check this document:
https://www.joshmcguigan.com/blog/inter ... istor-i2c/