I2C voltage levels

Hi all,
I am a first time user of this forum so I apologize in advance if this is the wrong place for this query.
I had a general question about the I2C pinout of both the Pixhawk 1.9 and Pixhawk 2.1 Cube boards/controllers. In the pinouts, the diagrams show that although the SDA and SCK lines run at 3.3 V using a pull-up resistor, the VCC pin supplies 5 V.

Why is there a difference between the voltage supplied to the peripheral and the voltage to run the SDA and SCK lines? How does the Pixhawk handle this? Does it use a voltage regulator?


Hi , in the MCU architecture the operating voltage is to 3.3V. The SDA and SCK are connected to the GPIO of the MCU. This is the standard voltage level also for UART and generally for the interfaces.


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Thanks for the response!
Here it shows Vcc is at 5V?

+5v Vcc is the voltage supplied to power devices connected to the i2c port. They are typically regulated down to 3.3v to supply the remote device’s electronics.

The levels are correctly stated as 3.3v logic levels.

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That makes a lot of sense! Thanks so much.