I have a DC signal that goes from 0-3V and need an op-amp circuit that converts this to -1V when the input is 0 and +12V when the input is 3V. So my equation will look like, Vout = (13/3)Vin -1. Can this be done with a non-inverting configuration or does it have to be inverting because of the -1? Ive been trying to design this for a few hours but nothing works out.

thanks.

 

Consider the standard non-inverting amplifier configuration:

The input goes directly to the non-inverting input while the output goes through two series resistors (R1 then R2) to ground and the feedback to the inverting input is taken from the junction of the two resistors.

Now consider what happens if you take the output to some other voltage (call it Vref) instead of ground?