Nifty I2C Level Shifter (two transistors)

[Speakerguy]

I'm working on a system where I have 5V and 3.3V devices that need to be connected via I2C, and I found the following app note to be quite helpful. It uses two inexpensive MOSFETS as level shifters in an odd configuration (the gates are always tied to 3.3VDC, while the sources are connected to the 3.3V I2C lines and the drains are connected to the 5V I2C lines).

Page 10 has the picture of the configuration.

(dead link deleted)

Any thoughts on this? I thought it was cool.

 

[Pommie]

It is rather good. It has been posted here before as a eagle schematic but I can't find it.

In most cases you would only need the level shifter on the data line if the master is the 5V chip.

Mike.

 

[AtomSoft]

https://www.standardics.nxp.com/support/documents/i2c/pdf/an97055.pdf

Link was dead above

 

[3v0]

The link was good yesterday.

It could be the NPX is working on their site.
Give it a few hours.

 

[Hero999]

How about attaching the file rather than linking.

To do this, paste the URL into the "Upload File from a URL" field in the manage attachments section.

 

[3v0]

How about attaching the file rather than linking.

Copyright ? Maybe I am living in the past.