battery DC/DC negative voltage powering op-amps

Discussion in 'The Projects Forum' started by justtrying, Mar 8, 2012.

  1. justtrying

    Thread Starter Active Member

    Mar 9, 2011
    My team and I are currently trying to figure out which battery to use for our project.

    I will not be able to provide info on how much current we need to supply, we are trying to figure out how to calculate it - we are using Arduino Uno, it says that input/output pins draw 40 mA of current so if we end up using all of them, that is 800 mA?

    Our main concern is to be able to power op-amps within the acquisition part of the circuit. One is an instrumentation amp and others are just regular TL081 (but we will likely switch to something better).

    What we are trying to determine is how to properly operate the op-amps from a single battery. We need stable rail voltages to avoid noise as our input signal is in uV range. The most common suggestion seems to be to configure op-amps as single rail but with multiple stages, I am uncertain about how the biasing will carry through each stage. Will the virtual ground created for one op-amp become common ground?

    I've attached the circuit as it is with dual supply...

    Thanks in advance for any input