A device includes an operational amplifier having a first input, a second input and an output, the operational amplifier configured to generate a first signal at the output. The device includes a reference resistor divider having a first and second resistor, a first terminal of the first resistor coupled to the second input of the operational amplifier. A second terminal of the first resistor is coupled to a first terminal of the second resistor and a second terminal of the second resistor coupled to an electrically neutral terminal. The device includes a voltage to current (V2I) converter having an input and an output, the input coupled to the output of the operational amplifier, and the V2I converter configured to generate a second signal at the output of the V2I converter. The device includes a switch coupled to the output of the V2I converter and to the reference resistor divider.