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AltIMU-10 v5 Sensor Schematic Help


Hi everyone,

I have been using sensor for some time and now i need to implement it to my pcb and i have a question.

The schematic has Q1 Q2 mosfets which are for level shifitng and my mcu is working with 3.3v logic so i will get rid of them. My question is should i also remove R3 R4 resistors since i think they belong to 3.3v side of level shifter circuit or should i leave them.




Pullup resistors like R3 and R4 are needed for I2C communication, so you should keep those in your design.



Thank you Jon for reply.

The mcu’s sda scl lines are pulled up, still do i have to keep R3 and R4.


The strength of the pull-up resistors you need on the SCL and SDA lines depends on a few things like the capacitance of the I2C bus and the frequency you want to use, but a common recommended value is something like 4.7k to 10k. If you already have pull-ups for those lines on your board, you do not need R3 and R4 as well. However, if you are talking about relying on the microcontroller’s internal pull-ups, you should probably still include R3 and R4 because internal pull-ups are typically significantly weaker than 10k. (If you find out later that the external pull-ups aren’t necessary, you can just not populate them on your board.)