MPL3115A2, I2C pull up

[owlowner]

MPL3115A2,Dose I2C need an external pull up voltage？or it has been pulled up inside by VDDIO？And can you give an advise for pull up resistance？

[shubhadippaul-b]

Yes, external pull ups should be applied to I2C lines for MPL3115. Suggested value is 4.7k.

Please refer to FRDMSTBC-P3115-SCH for a reference connection setup of MPL3115.

[owlowner]

Ok ，thank you。 What the function of VDDIO？

[TomasVaverka]

Hi Polo,

VDD is the main power supply for all internal analog and digital functional blocks.

VDDIO is a separate power supply pin used for the supply of the I2C digital communication interface.

So VDDIO sets the interface voltage level for the MPL3115A2 and your MCU. For single-supply operation, VDDIO can be the same as the main supply VDD. In a dual-supply applications, however, VDDIO can differ from VDD to accommodate the desired interface voltage.

Let us know if you have any other questions.

Best regards,

Tomas