aout dac chips

[soje]

I'm in the planning phase of adding a moog-clone filter to each output of my MBSID (it's got 2 chips). Being annoyed by the price of the dac chip, and having to order several places, I started looking at what was available.

 

Reichelt has this chip in stock:

 

http://www.reichelt.de/ICs-MCP-3-5-/MCP-4922-E-P/3/index.html?&ACTION=3&LA=446&ARTICLE=90090&GROUPID=5472&artnr=MCP+4922-E%2FP&SEARCH=12+bit+converter

 

Advantages:

- relatively cheap

- Scalability (you could start half-populating a board, adding more chips later as needed)

- It's available at Reichelt (meaning you can just order from one place)

- PID package, thru hole soldering instead of SMD

 

Disadvantages:

- Larger footprint

- ?

 

However I'm just a musician and music teacher dabbling in electronics, and I don't know what to look for in the datasheets, to compare it to it's job in the aout module needs. Could a couple of these chips be used instead of the TLV5630?

 

 

Cheers

Søren

[Shuriken]

I seem to remember a similar question before. There are actually several. But this answer from seppoman (designer/dev of the aout_ng module) answers most of your questions:

Edited November 29, 2013 by Shuriken

[TK.]

Yes, the voltage reference is the key, otherwise I would have already supported the MCP devices!

 

Best Regards, Thorsten.

[NorthernLightX]

@TK I have 2 spare MCP4822 (the version with the integrated voltage reference) that I can send you for free (I believe I already offered some to you a few years back) if you want to play with them.

Edited December 18, 2013 by NorthernLightX

[TK.]

Meanwhile I got a MCP4922, and also found a suitable voltage reference for 0.30 EUR at Reichelt.

 

Let me do some experiments with this chip first, it will be compatible to MCP4822 so that users have the choice.

 

Best Regards, Thorsten.

[TK.]

Ok, it works. :smile:

 

At least on the breadboard:

 

Schematics:

MCP4922 version w/ external VREF: http://www.ucapps.de/mbhp/mbhp_aout_mcp4922.pdf

MCP4822 version w/ internal VREF: http://www.ucapps.de/mbhp/mbhp_aout_mcp4822.pdf

 

This big disadvantage of the chip: it has no serial output, therefore modules can't be chained, but need dedicated chip select lines instead.

J19 provides only 2 CS lines, if more are required, additional IO pins have to be used - but not so many are available...

Therefore it won't be a good choice for projects like MIDIbox CV (or CV2)

But it will be a good choice for people who only need 2 (or maximum 4) channels.

 

Best Regards, Thorsten.