An electronic device may include a sensing circuit and a current subtraction circuit. The sensing circuit may output first and second current signals. The current subtraction circuit may mirror the first and second current signals onto first and second current branches. The second current branch may be split into a first sub-path and a second sub-path. An amplifier may control the amount of current flowing through the second sub-path by forcing the current flowing through the first current branch and the current flowing through the first sub-path to be identical. Configured in this way, the current flowing through the second sub-path will be equal to the difference between the first and second current signals. The current flowing through the second sub-path may be optionally amplified using another current mirror.