USB based DAC project

[bluetech]

Hello everyone,

I am new to electronic design and I have to build an audio circuit for a college project.

I have to design and build a USB based hi-quality audio DAC.

After having a mini research I found the PCM2205 IC from Texas Instruments that does the whole job and more. I wouldn't like to use this IC though because it will be very easy. I may do it at the end but i would like to try to buid some of the part myself and not use one chip for the whole project.

I would like to find an appropriate USB module and build the DAC on my own(ideally).

Is the UM232R USB module appropriate for my project?http://www.ftdichip.com/FTProducts.htm
Can you suggest me any other way of interfacing a DAC to USB

I would really appreciate any help either on the USB part or on the DAC part of the circuit (part numbers, circuits, links, ...)

Thank you

[Clutz]

I can't find any information on the PCM2205 IC, it's not listed on Texas Instruments website. That said, what you are going to want to do is get something like a PCM270x chip. This will act as the USB receiver, and it will output the I2S signal that many modern DACs use. After that, you've got a large number of options. Some good ones include the PCM1794/6/8. That is a pretty good one to go with because it has the digital filter uilt into it. If you use an older DAC, like say the PCM63, you will have to have a separate digital filter. If you wanted to go the NOS route, you could use the TDA1541A. I even believe I've seen some NONOS designs using the AD1865 chip.

But picking out the chips that you want to use is the easy part. You also have to work out the power supplies and voltage regulation, and then finally you have to do the schematic and the layout.

Originally posted by bluetech
Hello everyone,

I am new to electronic design and I have to build an audio circuit for a college project.

I have to design and build a USB based hi-quality audio DAC.

After having a mini research I found the PCM2205 IC from Texas Instruments that does the whole job and more. I wouldn't like to use this IC though because it will be very easy. I may do it at the end but i would like to try to buid some of the part myself and not use one chip for the whole project.

I would like to find an appropriate USB module and build the DAC on my own(ideally).

Is the UM232R USB module appropriate for my project?http://www.ftdichip.com/FTProducts.htm
Can you suggest me any other way of interfacing a DAC to USB

I would really appreciate any help either on the USB part or on the DAC part of the circuit (part numbers, circuits, links, ...)

Thank you

[bluetech]

Thank for the reply

Sorry i made a mistake. I ment the PCM27xx series. I can find from Farnell the PCM2702EG4, PCM2704DB, PCM2705DB or the PCM2702E. I was ment to write PCM2705

Before i use any of those ICs, I would like to try with an external USB module like the UM232R
http://www.ftdichip.com/FTProducts.htm

Has anyone ever used one of those or similar?

thank you

[dddac]

sure,

check my website, it is all there

doede

website usb dac



or direct

[bluetech]

Hello,
I've just realized today that there are in the market USB microcontrollers. For example the PIC18F2450. http://www.microchip.com/stellent/id...cName=en023497

So far i have used only much smaller micros for silly LED flashing projects. Does anyone know if I can use this for my project and how difficult will be?

Thank you.

[b-square]

It is unclear what you are trying to accomplish here. You can use one of the PCM270X family parts to get your USB->I2S interface easily, then hook almost any DAC up to the I2S side. If you are worried about how hard using a part not optimized for this application will be, use the PCM270X. You seem to be asking for a setup that is easy...but not too easy.

[planet10]

Originally posted by b-square
You can use one of the PCM270X family parts to get your USB->I2S interface

You can also use the DAC built into the PCM270x... an idea i would have poo-pooed until i heard quite a decent exection of it (in the KingRex T20U). This outperformed a DAC using 270x>IS2>1543 that cost more than the KingRex.

dave

[b-square]

Originally posted by planet10


You can also use the DAC built into the PCM270x... an idea i would have poo-pooed until i heard quite a decent exection of it (in the KingRex T20U). This outperformed a DAC using 270x>IS2>1543 that cost more than the KingRex.

dave

Re-read OP. He specifically does not want to use an integrated solution as this is a school project to learn something (but not too much!).

bb

[Archwn]

Hi Dave,

What is in KingRex T20U then? Just for the record.

[b-square]

One of the PCM270X devices from TI, just like he said.