hamster

ADAU1761 Audio codec.

Recommended Posts

I'm playing around with the ADAU1761 Audio codec chip (http://www.analog.com/static/imported-files/data_sheets/ADAU1761.pdf) on my Zedboard, and almost have it working.

 

It is a pretty amazing we device, as well as capturing analog into I2S, and going from I2S to analog and digital it has an inbuilt DSP, and a GUI programming tool SigmaStudio (http://www.analog.com/en/content/cu_over_sigmastudio_graphical_dev_tool_overview/fca.html)

 

One of the neat features is that it has an inbuilt PLL for generating the I2S clocks and driving the DACs - something the other I2S DAC I have doesn't have, and allows a bang-on 96,000, 48,000 or 44,100 sample rate.

 

Once I get this working, I'm thinking of attempting to build a WIng for the Papilio.

 

Would anybody be interested in this?

 

 

 

 

 

 

Share this post


Link to post
Share on other sites

The device has lots of inputs and outputs - to wire them all that is around seven 3.5mm sockets

 

I'm thinking just a single line in, and then just headphone and line out. Unless anybody really needs differentai inputs or a four channel stereo mixer in front of a ADC?

Share this post


Link to post
Share on other sites

How about sending the more esoteric connections to pads for a standard pin header? No additional cost, and they're available for anyone who does decide to play with them.

Share this post


Link to post
Share on other sites

Yeah, been looking into it. The device is in a 5mm^2 32-LFCSP-VQ package, and are about $15 per piece

 

That alone has given me a reason to pause. I'm petty sure I'ld need to have a stencils and a 4 layer board, which requires a paid-for license of Eagle.

 

It is rapidly starting to look very expensive to tool up. 

Share this post


Link to post
Share on other sites

Hey Hamster,

 

Looks like they are only $10 in singles at digikey and available for around $5 on Chinese market. So price is not too bad really.

 

I also wouldn't worry at all about that form factor, it should be a piece of cake to solder it and there is no need for a 4 layer board from what I see...

 

For a couple prototypes I wouldn't bother with a stencil. Just get some solder paste in a syringe, I get mine here, and some syringe tips and you can just lay down the solder paste where you need it. Put it in the toaster oven and let the solder flow. It won't be right, I don't even bother trying to make it right and usually just lay down a straight line of solder across all of the pins. Just make sure you don't put too much solder so that there are bridges between the center pad and the leads on the outside.

 

Then use plenty of flux from a flux pen, I use this, and use your solder iron to drag the solder across all of the pins. Its called the drag technique and it will clean up all of your pins no matter how close they are. Then to remove all of the excess solder from the last couple of pins that you dragged all the solder onto use some copper solder wick. The key here is having good flux, well that is the key to good soldering anyway.

 

Worst case scenario if you design it I will build some prototypes for us.

 

Jack.

Share this post


Link to post
Share on other sites

Here is a great video showing the drag technique and many others.

 

It also points out how important it is to tin your solder tip. You should be tinning your tip after every use, whenever you park your soldering iron in the holder you should tin the tip first. (Sorry, I worked at a assembly plant when I was in high school and went through a two week soldering course where it was drilled into us so I'm always surprised to learn people don't already know this information. I always assume people know this and then when people ask why they have to change tips so often I ask them if they are tinning their tip after ever pin they solder and they say no... So now I just always bring it up whether people already know it or not.)

 

I also find that a sponge is way, way better then those scratchy pads. If you tin your tip after every single solder then your tip will last for years and will be highly responsive, but you will be wiping a lot of solder off the tip and a sponge does that best.

Share this post


Link to post
Share on other sites

You can't use the drag technique with a LFCSP-VQ package because there aren't any exposed pins, just pads on the underside. It's not too hard to do with a hot plate or reflow oven though. I haven't looked closely at the pinout but a multilayer board shouldn't be necessary for something like this, it's only really needed when you move up to BGA and have a very high pin density along with the need for very low impedance supply and ground connections to numerous pins.

 

If multilayer is necessary, I'm not sure why so many folks still use Eagle. I switched to Kicad years ago and have never looked back. It's completely free, open source, cross platform, not limited in any way. The interface has quirks, but so does every EDA package I've tried. I've used it to create dozens of boards from smaller than a postage stamp to 8"x10" and have yet to run into a design it couldn't handle.

Share this post


Link to post
Share on other sites

THe multilayer is recommended for heatig issues (headphone power amps), and to get good performance for the 24-bit DACs.

 

I'm quite happy to reflow in my oven, so the problem would be getting the right amount of solder under the device, hence the need for a stencil.

 

I guess I am just going to have to learn Kicad. :-)

Share this post


Link to post
Share on other sites

Look at the picture, the pads are exposed from the side:

32LFCSP.jpg

I have personally used the drag technique with this package before. It did suck but I was able to repair solder bridges using the drag technique. I would try to be very careful when laying down the solder with the syringe and try to get them only on the necessary pads. You can also use a toothpick or dental pick to get just the right amount of solder, unless of course you want to go the stencil route. But my experience is you would need a stainless steel stencil for this pitch, a kapton stencil won't be good enough and you will have to do rework anyway.
 

Anyway, there are lots of different ways to tackle soldering this chip, I'm just saying it is definitely doable.

 

Jack.

Share this post


Link to post
Share on other sites

you can buy stencil for the chip alone here:

http://www.proto-advantage.com/store/product_info.php?products_id=3250020

 

Or an kit with protopcb, paste, squeegee etc:

http://www.proto-advantage.com/store/product_info.php?products_id=3050020

 

Or for prototyping, I usually order like this:

http://www.proto-advantage.com/store/product_info.php?products_id=3150020

and fill in the digikey number, and after some days you have it soldered for you. 

Share this post


Link to post
Share on other sites

you can buy stencil for the chip alone here:

http://www.proto-advantage.com/store/product_info.php?products_id=3250020

 

Or an kit with protopcb, paste, squeegee etc:

http://www.proto-advantage.com/store/product_info.php?products_id=3050020

 

Or for prototyping, I usually order like this:

http://www.proto-advantage.com/store/product_info.php?products_id=3150020

and fill in the digikey number, and after some days you have it soldered for you. 

 

Oh! Those are excellent links!

 

Jack.

Share this post


Link to post
Share on other sites

I noticed that they have some various versions of the same thing, various pad sizes, pitches etc, but looking at the datasheet narrowed it down to those.

I typically send them an email when I'm not sure, and they check for me so I get the right thing, good people.

Share this post


Link to post
Share on other sites

I usually use a toothpick to apply the paste. I've found if the solder paste is a bit old it helps a lot to mix in a bit of liquid flux to get the right consistency and then it works. Another technique I've used is to use the drag trick to tin all the pads, then add a bit more flux, set the part in place and reflow it on the hot plate. It doesn't take much solder and too much causes more problems than too little. I've never had the luxury of having stencils but a few times I've been tempted to try making one. Apparently they can be etched out of thin copper using the same toner transfer process I use to make PCBs.

Share this post


Link to post
Share on other sites

Well, with all this interest I'm going to have a go at Kicad and give this a crack.

 

- 8-bit Wing

- Four stereo sockets

- Line in (1V pp level)

- Microphone in

- Line out

- Headphone out

- ADAU1761 codec

 

I''ve yet to do a BOM, but given that the PCB will be $4, the Codec $16, sockets are about $1 each and there is quite a few little bits passive bits involved it will be about $30 per board, plus $10 for shipping.

 

Anybody still interested in one?

Share this post


Link to post
Share on other sites

I don't have Cameo, they would be very expensive to get over here.

But it works, there are some various scripts that they have used, various types of vinyl that works better than others and so on, I would recomend you to read it, even if it is long. 

Share this post


Link to post
Share on other sites

Been slowly working on this, and stumbled onto the following part:  http://www.farnell.com/datasheets/826709.pdf

 

"WM8731SEDS/RV - DAC, AUDIO, 24BIT, HEADPHONE, 28SSOP"

 

Not as feature-rich as the ADAU1761, (no on-board DSP, no AUX input, only one stereo headphone channel, no PLL) but still looks pretty useful - about US$10 and in a 28 pin SSOP package, and 68 are in stock at Element 14!

 

Just done a quick PCB  with just the major components on it (Codec, XTAL, Wing header,3x3.5mm sockets). It looks to be as big as a 16 bit wing, but it only needs eight FPGA pins.

 

Not sure if I should have a go as a 16-bit sized wing, or as a non-standard 8-bit wing that extends above the headers.

 

Anybody have any opinion? Still look useful to others? 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now