OPA316, level shift input signal, buffer output

[Vindhyachal.takniki]

1. I have application where input signal voltage varies from +5V to -5V. Have to level shift the signal and fed it to microcontroller adc which is sampling at 1MSPS. Microcontroller adc range varies from 0V to 3.3V
Selected OPA316 for this application. Attached find the circuit.

2. Can I level shift the signal using single supply opamp(3.3V) volt from +-5V to 0-3.3Vdc

3. I have calculated resistor values as in attached ckt. I dont have opamp right now, but if I simulate the resistor network without opamp, on applying +5V at vin, I got +3.3V at In+ & on applying -5V at Vin, I get 0V at In+.

4. Is this ckt ok? What error margin I should take for voltage range?
i think 1% resistor values will be ok.

[Zero999]

All the op-amp does is buffer the signal. If the ADC has a high input impedance, then the op-amp can be omitted and it will still work perfectly.

[Syntax_Error]

https://www.google.com/?gws_rd=ssl#q=op+amps+for+everyone+pdf

Provided without sarcasm or attitude. I include the search list instead of a link to the PDF in question because this provides additional tools and information. This PDF (Op Amps for Everyone) is simply written and very very useful for these type of conversion requirements.

[rstofer]

Again, "Op Amps For Everyone" is a great reference.  See section 4.3, pick the right case and follow the yellow brick road.

I would get rid of the 10k resistor between the op amp and the ADC.  MANY uC ADCs want to see a fairly low impedance source - like 2k (check the datasheet for your uC).  The resistor serves no purpose and it can get in the way.  If you want to protect the uC pin, try a 330 Ohm resistor instead.

[Syntax_Error]

Here's a few more.

http://www.ti.com/lit/an/slyt104/slyt104.pdf
http://www.ti.com/lit/an/sloa098/sloa098.pdf
http://www.ti.com/lit/an/sloa097/sloa097.pdf

All seem relevant to your application.

[Vindhyachal.takniki]

Thanks

[danadak]

There are a number of ways of solving this, from something as simple as
2 R's to developing a simple - supply for the OpAmp to expand its CM
range.

https://www.dropbox.com/s/k1yn4m7heaixvmg/ADinput%20negative%20inputs.zip?dl=0


Regards, Dana.

[Vindhyachal.takniki]

This ckt works. But it has one major consideration that source voltage should be able to both source & sink current.
Let say I have a sensor which is not able to sink current like theromocouple. Suppose I have sensor with +-5V & it dont sink current.
In that case what would be the ideal solution?