Many electronic circuits rely on the ratio of one component to other components being well defined. Current flow in component can warm the component causing its electrical properties to change, for example the resistance of a resistor may increase due to self-heating as a result of current flow. The present disclosure provides a way to reduce temperature variation between components so as to reduce electrical mismatch between them or the consequences of such mismatch. This is important as even a change of resistance of, for example, 20-50 ppm in a resistor can result in non-linearity exceeding the least significant bit value of a 16 bit digital to analog converter.