OPA316, level shift input signal, buffer output

Discussion in 'General Electronics Chat' started by Vindhyachal Takniki, Sep 13, 2016.

  1. Vindhyachal Takniki

    Thread Starter Member

    Nov 3, 2014
    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.
  2. AlbertHall

    Distinguished Member

    Jun 4, 2014
    Looks OK to me.
    Vindhyachal Takniki likes this.
  3. Vindhyachal Takniki

    Thread Starter Member

    Nov 3, 2014
    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?