A circuit includes an output node; a first current source coupled via at least one first switch to at least the output node and a calibration node, wherein the first switch alternately operably couples the first current source to the output node or the calibration node; a second current source of opposing polarity to the first current source and operably coupled via at least one second switch to at least the output node and the calibration node, wherein the second switch alternately operably couples the second current source to the output node or the calibration node; and a current control circuit having an adjustment circuit operably coupled to the calibration node, wherein the current control circuit couples both the first and second current sources to the calibration node when a current from the first/second current source is not to be used as an output from the output node.