An apparatus includes a plurality of series-connected current control circuits configured to control a current therethrough responsive to at least one current reference signal and to be coupled in parallel with a load, such as a string of LEDs. The apparatus further includes a voltage control circuit configured to control respective voltages across respective ones of the current control circuits. In some embodiments, the voltage control circuit may be configured to individually adjust responses of the current control circuits responsive to the voltages across the current control circuits. In further embodiments, the voltage control circuit may include respective voltage limiters coupled across respective ones of the current control circuits.