TI PCM2902

Anyone familiar with this chip? I asked because it features in a recent Everyday practical Electronics project for a two channel test instrument included spectrum analyser and scope. its not the world's greatest CODEC but it seem pretty competent, works with standard USB drivers and is USB 2 compatible. OK, max sampling rate is only 48K and its a 16 bit device but it could make the basis of a low cost DIY audio test set. TI does a ready built evaluation board for just over $100 Add a few THAT chips and you are in business.

Cheers

Ian

I'm the systems guy for the part at TI.
I've dreamt of making the same thing many times.

Drop me a pm if you have any q's. this would be an awesome module to run on my pnp machine.

/R

Rochey said:

I'm the systems guy for the part at TI.
I've dreamt of making the same thing many times.

Drop me a pm if you have any q's. this would be an awesome module to run on my pnp machine.

/R

Click to expand...

Cool!! The project in the UK mag uses some software called Multi-Instrument 3.2 by Virtins Technology based in Singapore. SOunds very good but do you think any software like RMA could be used with this chip?

Cheers

Ian

Without a doubt.

It uses the generic USB class audio driver

Behringer does a ton of boxes with these it's inside, for about 30 dollars... 20 quid?

I have been chomping at the bit to revisit my old TS-1 design from the '80s, using modern technology so have given this a lot of thought.

The main issues I see with using something like the 2902 is that it is a dedicated audio frequency codec so may not be optimal for wide band bench measurement. BUT MORE IMPORTANTLY, what could you do in that hardware, that can't be done with software and a good computer sound card, or smart phone (while smart phone codecs are generally stronger on the D/A side than A/D.

If we take a small step backwards and look at how real test equipment is designed, they generally combine a switchable front end gain stage/filter set, with a lower dynamic range back end.

I suspect combining even a lesser codec like found inside a cheap micro with something like the THAT mic preamp with digital gain control could work in combination to make respectable low noise measurements.

I have resisted such a project in light of the potential for cheap competition.

JR

JohnRoberts said:

If we take a small step backwards and look at how real test equipment is designed, they generally combine a switchable front end gain stage/filter set, with a lower dynamic range back end.

JR

Click to expand...

Which is pretty much what the EPE project does. It even uses a couple of Lorlin switches:

http://www.epemag.com/proj/1213.html

Cheers

Ian

ruffrecords said:

Anyone familiar with this chip? I asked because it features in a recent Everyday practical Electronics project for a two channel test instrument included spectrum analyser and scope. its not the world's greatest CODEC but it seem pretty competent, works with standard USB drivers and is USB 2 compatible. OK, max sampling rate is only 48K and its a 16 bit device but it could make the basis of a low cost DIY audio test set. TI does a ready built evaluation board for just over $100 Add a few THAT chips and you are in business.

Click to expand...

Also limited to 16-bit 48 kHz is the Silicon Labs CP2114. You provide the converters. One bonus of this guy is that it features a UART and a handful of GPIO signals which you can use for volume and mute controls. It too uses the standard USB Audio Class so no drivers are required.

And if you're really into it all, get an ARM with an I2S port and USB device support and go from there.

-a

Andy Peters said:

ruffrecords said:

Anyone familiar with this chip? I asked because it features in a recent Everyday practical Electronics project for a two channel test instrument included spectrum analyser and scope. its not the world's greatest CODEC but it seem pretty competent, works with standard USB drivers and is USB 2 compatible. OK, max sampling rate is only 48K and its a 16 bit device but it could make the basis of a low cost DIY audio test set. TI does a ready built evaluation board for just over $100 Add a few THAT chips and you are in business.

Click to expand...

Also limited to 16-bit 48 kHz is the Silicon Labs CP2114. You provide the converters. One bonus of this guy is that it features a UART and a handful of GPIO signals which you can use for volume and mute controls. It too uses the standard USB Audio Class so no drivers are required.

And if you're really into it all, get an ARM with an I2S port and USB device support and go from there.

-a

Click to expand...

ARM here:
http://www.embeddedartists.com/products/app/labtool.php

Andy Peters said:

And if you're really into it all, get an ARM with an I2S port and USB device support and go from there.

-a

Click to expand...

I think we have been here before on an earlier thread about using the Raspberry Pi as the basis of a test set. The model B supports I2S and it is of course ARM based.

Cheers

Ian

Hello,
I've build similar project years ago by using this chip (c version) with VA2012.64-beta-0.4.2  software.http://casa.accattatis.org:9090/Latest%20VA%20version/?size. You can try it with your soundcard for testing, very impressive software.
I should have schematics somewhere if you are interested...