The connection diagram for BMP390 recommends 4.7k resistors connected between the SDA and VDDIO. If the board I am designing already has 100k resistors connected between those two lines in parallel are the 4.7k resistors necessary? Also will the sensor still function as normal with 100k instead of 4.7k?
If the board I am designing already has 100k resistors connected between those two lines in parallel are the 4.7k resistors necessary?
Reply:What is the purpose of this design?
Also will the sensor still function as normal with 100k instead of 4.7k?
Reply:I2C interface equipment needs to follow the hardware design. You can refer to the I2C interface specification. Excessive resistance will greatly reduce the I2C communication rate.
I am designing an AHRS sensor that connects to a Raspberry Pi. There is a voltage translator that converts the 3.3 V power supply from the Raspberry Pi to 1.8 V for the components such as the pressure sensor to operate at their typical input voltage. The datasheet for the translator recommends 200k pull-up resistors between SDA and SCL lines. Right now my design has 100k resistors and if I were to follow the connection diagram for BMP390 I would be adding the 4.7k resistors in parallel with the 100k resistors that are already in the design, which is why I'm asking if the 4.7k resistors are necessary when I already have the other 100k resistors.
I think it is not good way that you want to convert 3.3V, 1.8V by resistance, the recommended way is to use a special voltage conversion chip.