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New Contributor
bmassey
Posts: 2
Registered: ‎04-18-2013

CP2112 SINGLE-CHIP HID USB TO SMBUS MASTER BRIDGE

Does the CP2112 work as USB-to-I2C bridge? If yes, please provide link to documentation. Do you have an CP21XX that is an actual USB-to-I2C bridge device? If yes, please provide link. If not, why not? I'd prefer not to use FTDI, but need actual USB-to-I2C interface bridge IC. Thanks.
Community Moderator
Tabitha
Posts: 351
Registered: ‎10-12-2004

Re: CP2112 SINGLE-CHIP HID USB TO SMBUS MASTER BRIDGE

Hi Bruce,

The CP2112 is an HID USB to I2C/SMBus bridge. You can find all of the documentation for it here by clicking on the Documentation tab at the top:

http://www.silabs.com/products/interface/usbtouart/Pages/HID-USB-to-SMBus-Bridge.aspx

Because it's an HID device, you do not need to maintain or install a USB driver to use it. The software you write can use the standard HID functions to communicate with it. The CP2112 interface and software examples are also provided on the webpage I linked above from the Tools tab. You'll want to install the CP2112_Setup.exe package.

Regards,
~Tabi
Tabitha Parker
MCU Applications and Support Manager - Austin
Silicon Laboratories
New Contributor
bmassey
Posts: 2
Registered: ‎04-18-2013

Re: CP2112 SINGLE-CHIP HID USB TO SMBUS MASTER BRIDGE

Hi Tabitha,
OK, thanks. Since USB-to-I2C is a common interface, it would be helpful to others as well as myself to have an example of I2C-only interfacing using CP2112. Maybe it exists somewhere in the documentation. SMBus and I2C are different. Not sure by how much. I will not spend too much time to determine what's needed for I2C only, even if minor differences to SMBus. An I2C only example would be helpful. If I missed it, please let me know. In the mean time we will work w/ I2C-only devices. My appl. is for USB-to-I2C at 400kBd. Thanks, Bruce
Community Moderator
Tabitha
Posts: 351
Registered: ‎10-12-2004

Re: CP2112 SINGLE-CHIP HID USB TO SMBUS MASTER BRIDGE

Hi Bruce,

You're welcome!

For the differences between I2C and SMBus, I recommend reading through the Wikipedia article:

http://en.wikipedia.org/wiki/I%C2%B2C

For the most part, I2C and SMBus are compatible with each other. You should be able to use the CP2112 with your I2C system without any issues. You may want to check the end device's datasheet to see if it mentions compatibility or incompatibility with SMBus devices.

Regards,
~Tabi
Tabitha Parker
MCU Applications and Support Manager - Austin
Silicon Laboratories