Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Invert output from DAC

Status
Not open for further replies.
M

MarcoAndarcia

Newbie level 4
Newbie level 4
Joined
Oct 31, 2012
Messages
5
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,322
Hi,

I am working on a project in which I have to invert the voltage from a DAC that I have chosen. This DAC works from an I2C bus; however it can only produce voltages from 0-5V, I would like to be able to invert this output and make it from -5V to 0V. I know I can build an inverter buffer using Op-Amps however my end goal is to be able to produce outputs from -5V to 5V. I believe there is an IC capable of turning my positive voltage and convert it into negative voltage if I choose so. I haven't been able to find this IC unfortunately, nor I2C DAC that produce negative and positive voltages with 14 bit or higher resolution.

Thanks in Advance.
 
Last edited:

You can do this with many op-amps. What you need to do is offset the voltage by 2.5V so it ranges from -2.5 to +2.5 then amplify it x2 to make it -5.0 to +5.0.

Brian.
 

Hi Brian

I am leaving this option for last since I would have to take into account the offset of the op-amp, and I would need a low noise ref psu. I am currently looking into SPI -DAC but haven't found one with at least 4 converter and is 16 bits.

Thanks.

Marco.
 

In case this helps with the topic now (or later)...

Here's a screenshot of an op amp converting an input of 0-5V, to an output of -5 to +5:



The second configuration inverts the signal, in case that is what you mean by the word 'invert'.
 

does your DAC produce these voltages directly, or does it output(/input) a current ?
 

Yes, I know I can make an inverting amplifier with gain 2 but it introduces some noise, and I would have to workout the offset of the op-amp, I think I will have to do it anyways, I have been looking for a part that has the op-amp and internal reference in the same IC. The DAC that I am using right now outputs voltage, but only from 0-5V.
 

Wouldn't it be reasonable to use the same reference as the DAC rather than using a second reference? This reduces the problem to a trivial 1 OP 4 resistors design.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top