The I2C Isolation Breakout has finished its inital testing!

The I2C Isolation Breakout has finished its inital testing!

I just finished building an initial batch and am very pleased after testing. The voltage output selection between 3.3 and 5v works great and the output is pretty stable! Most importantly it isolates the I2C unit it plug into. The single supply aspect works really well, and makes this a simple drop in series placement between host and I2C device. If you need to use a separate external supply for the I2C device to isolate, simple disable the power IC with the selection jumper (you can leave it open to enable the pin for external selection control). Anyway, here’s a bit more infor below and don’t forget to check out the project page!

There are many times when it is important to prove galvanic I2C isolation. I2C is a very popular method of communication and is growing is use all the time, it is easy to use and allows a vast array of peripherals and can be somewhat fast at that. It does have some weaknesses and when paired with sensors that are susceptible to noise can present issues (poor design, ground loops, too much capacitance, are example of some of the problems). One method to some of these problems should the crop up is to use galvanic isolation to separate out the “sensitive” portions from the other.

You can also place more than one of the same address on the bus and use SDL switching to block the non preferred device to access. There are a large number of reason why one would need to do this!

I2C level conversion can be very difficult especially at higher speeds (400Khz and 1Mhz can be problematic). One of the cool side effect of the I2C isolation breakout is how natural it lends itself to level conversion, it is really handy when you use an external power supply and operate at potentials much higher than the host would be at.