inverting amplifier

Hi, Hope everyone is doing great. I am building a circuit in LTSpice using the inverting configuration of the LT1028 operational amplifier. The input signal provided is 0.7 Vp, which is applied to R1 (5M ohm). For the feedback resistor (Rf), I am using my biosensor, whose impedance varies from...

Hello, I'm having trouble thinking of a way to convert a negative voltage to a positive one with an inverting OPA. I have an input voltage range of [-5 to -1]V and I need to convert it into a positive voltage to compare it with a reference voltage ( regulation for my charge pump) and I only...