Ask you heroes if there is a mature circuit connecting 3V and 5V of I2C. Although MAX and ADI have related chips, the price is higher and the order is not easy. Hope there is a simple and practical circuit.
Jackson postato su August 7, 2020
It is divided into two parts: 3.3V to 5V is solved with HC series buffers, and 5V to 3.3V is solved with series resistors.
Aaron postato su August 7, 2020
It can be directly connected without additional conversion. The I2C bus protocol has such a benefit. The I2C bus stipulates that the SCL and SDA lines must be "open-drain" structures, and external pull circuits are required. For 3V and 5V devices, their I2C bus can be directly connected-because it is open drain, there is no problem.
Adam postato su August 7, 2020
It can be connected directly. I have made a card reading circuit, and it is powered by 5V. But when I went to buy the card, I was told that there was no 5V card sold, only 3.3V. I took it back and tried it, and I still used it.
