A system including a first transistor, a second transistor, and a comparator. The first transistor is configured to supply a first current to a first load connected to a first terminal of the first transistor. The second transistor is configured to supply a second current to a second load connected to a first terminal of the second transistor, wherein the first current and the second current have a predetermined ratio. The comparator is configured to compare a voltage at the first terminal of the first transistor or a voltage at the first terminal of the second transistor to a reference voltage, and to adjust, based on the comparison, biasing of the first transistor and the second transistor to maintain the predetermined ratio between the first current and the second current.