A circuit includes a current source series-connected with a load between first and second terminals and an element coupled in parallel with the load between the first and second terminals. A value of a current in the current source is controlled based on a current flowing in the element between the first and second terminals. The value of the current in the current source is controlled proportional to power consumption in the load based on the current flowing in the element between the first and second terminals. The element is used to limit a voltage across the load while the value of the current is being controlled.