FTDI Community

General Category => Discussion - Hardware => Topic started by: lsburden on March 07, 2018, 08:08:06 PM

Title: Looking for USB-I2C for DAC & ADC
Post by: lsburden on March 07, 2018, 08:08:06 PM
I'm an Analog Design Engineer and somewhat inexperienced with USB bridges.
I am looking for a USB to I2C bridge for audio converter applications. I'm looking for at least USB 2.0, 24 bit, 48k sample rate - more bit depth and higher sample rates preferred.
How do you determine bit depth and sample rate from typical USB bridge specs?

Searches have turned up the FT201X and the FT90X. Are either of these viable? The FT90X looks like a much higher performing part but maybe something better suited for the more experienced?

Some guidance would be great!

Thank you,
Lucas
Title: Re: Looking for USB-I2C for DAC & ADC
Post by: FTDI Community on March 08, 2018, 11:52:20 AM
Hello,
Are you looking for an I2C master or slave?
Here are our USB to I2C solutions available which are all at least USB 2.0 and support I2C data transfers up to 3.4Mbps.

I2C slave only:
FT200XD (http://www.ftdichip.com/Products/ICs/FT200XD.html)
FT201X (http://www.ftdichip.com/Products/ICs/FT201X.html)

I2C master only (using MPSSE engine. LibMPSSE could be used. See AN_177 (http://www.ftdichip.com/Support/Documents/AppNotes/AN_177_User_Guide_For_LibMPSSE-I2C.pdf)):
FT232H (http://www.ftdichip.com/Products/ICs/FT232H.htm)
FT2232H (http://www.ftdichip.com/Products/ICs/FT2232H.html)
FT4232H (http://www.ftdichip.com/Products/ICs/FT4232H.htm)

I2C master only (using HID class driver. LibFT260 could be used.):
FT260 (http://www.ftdichip.com/Products/ICs/FT260.html)

I2C master or slave:
FT4222H (http://www.ftdichip.com/Products/ICs/FT4222H.html) (using D2XX drivers and LibFT4222)
FT90x (http://www.ftdichip.com/Products/ICs/FT90X.html) / FT93x (http://www.ftdichip.com/Products/ICs/FT93X.html) (these are indeed MCUs and would require software development to bridge to the USB port. See AN_360 FT9xx Example Applications  (http://brtchip.com/wp-content/uploads/Support/Documentation/Application_Notes/ICs/MCU/AN-360-FT9xx-Example-Applications.pdf)for more information).

We have Development Modules (http://www.ftdichip.com/Products/Modules/DevelopmentModules.htm) available for test and evaluation.

Best Regards,
FTDI Community
Title: Re: Looking for USB-I2C for DAC & ADC
Post by: lsburden on March 12, 2018, 07:49:18 PM
Sorry I have not responded sooner. I didn't know that there was I2C master and slave.
In the audio converter projects I worked on the distinction was not made. I guess these were purpose built devices so there was no need to point it out.

As I understand - the master controls the clock and initiates the transfer(?). If that is correct than it seems to me that a DAC would require and I2C master and an I2C slave for an ADC. Is that correct?
Title: Re: Looking for USB-I2C for DAC & ADC
Post by: FTDI Community on March 13, 2018, 09:55:44 AM
Hello,

Yes there are I2C masters and slaves. The master always provides the clock and initiates the communication.

You would need to check the specification of the device you are trying to connect to.

It's not necessarily the case that a DAC would require and I2C master and an I2C slave for an ADC.

Best Regards,
FTDI Community
Title: Re: Looking for USB-I2C for DAC & ADC
Post by: lsburden on March 14, 2018, 08:26:11 PM
Ok, I think I have it figured out, or at least how to figure out if the converter is a master, slave, or configurable.