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Convert 0/3.3V DAC and ADC to -10/+10 V ?

Texton

Jul 27, 2012
14
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Jul 27, 2012
Messages
14
Hi all.

I got this project, where i am using a microcontroller (PSoC5) which has both DAC's and ADC's build in. Theese are both 0V to 3.3V (the ADC can measure this interval and the DAC can generate it).

Now I have to do some regulation/digital filtering with the microcontroller, and for that I need to make the ADC measure -10V to 10V and the DAC generate the same.

I got some ideas: a voltage divider to scale down for the ADC and a OP AMP for scaling up the DAC output.

But I wanted you guys opinion, experience and ideas for this? is there a better/safer/less noisier way? and btw. I need a bandwidth at 50kHz.

Thanks :)
 

GreenGiant

Feb 9, 2012
842
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Feb 9, 2012
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842
measuring -10 to 10 shouldnt be that difficult, as you said that will just be a divider as you said
and as far as the DAC converting that will be a little more difficult if you need good resolution, I know that with the Arduino (not what you are using but its a microcontroller) has a resolution of 2^8 - 1 (in this case 78 millivolts a step), this isnt super great accuracy if you need it, now if I was going to do something like that I would spread the output over 2 pins, one for negative and one for positive this will increase the resolution to 39 millivolts per step
and since you know the output max is going to be 3.3 then you can use an op amp with a gain of 3 and that should work for you.
 

Texton

Jul 27, 2012
14
Joined
Jul 27, 2012
Messages
14
Yup that was what I thought. Thanks for confirming :) .. And about the resolution, the PSoC5 got a 16bit DAC (I think it actually parrallels 2 8bit DACs internally).
 
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