DAC(Digital to analog converter)

[mcad]

Hello all;
I am searching for the resource about DAC(Digital to analog converter)
If you have, would you please give me the link ?

Thanks

[PCM programmer]

Yes, look at the list of CCS drivers. Find a DAC that is in the list.
Then you will already have a working driver for the DAC chip. You don't
need to write a driver. For example, look at the MCP4921.
http://www.ccsinfo.com/content.php?page=devicedatasheets
You can also download the data sheet for the DAC chip from this page.

[Guest]

Hımm,
thanks for this but I am searching for something tutorial which explains the main points about this on circuits.
For example, there exists a output buffer and network circuits in the DAC.
So, what is the relationship between them ?
I am searching for a source which answer such question.

Thanks

[Ttelmah]

There is not an 'output buffer', in a lot of ADC's. The answer for this, is always to look at the device data sheet.
As with ADC's, there are a lot of different types, depending on applications. Basically, the simplest, is a linear resistor network, with MOSFET switches, connecting to the nodes between the resistors. The mosfets allow the selectable 'tap', to be software positioned to the required location. Downside is that it means a lot of resistors, and a lot of switching FETs. Plus side is that accuracy is only dependant on the accuracy to which the resistors can be made, and with such a design it is always guaranteed that a higher selection, will give a higher output Second (commoner) type, uses a R-2R network. Have a look at avr-asm-tutorial .net, who have a tutorial about this network, and building a simple DAC with it. As the number of bits grows, this puts increasingly costly accuracy requirements on the resistors involved.
You will also find types that use other 'tricks', to give higher ranges (PWM for example, or linear networks, then feeding R-2R networks), and modifications to the selected values, to give non linear responses for audio applications.
Since the systems all involve some form of resistor network, or capacitor charge/discharge (for the PWM designs), a buffer is then needed to prevent the result changing with load. In many cases this is integrated, but in some it is not.
In some ways the best way to understand a DAC, is to build a simple one, and play with it. It is basic very low level electronics.

Best Wishes

[SherpaDoug]

Google "R2R networks" to see how the simplest type of DAC works. Then build one with a PIC and a few resistors. Then add a comparator and some PIC code to build a ADC.
_________________
The search for better is endless. Instead simply find very good and get the job done.

[Guest]

Sorry, I implied the DAC, not ADC. Again sorry for this conflict.

[adrian]

If you want to start with the basics try here:
http://www.analog.com/library/analogDialogue/archives/39-06/Chapter%203%20Data%20Converter%20Architectures%20F.pdf