Patent ID: 8645726

Claim:
A system comprising: a first power supply unit comprising a first coarse adjustment circuit configured to adjust output current of the first power supply unit; a second power supply unit coupled to the first power supply unit, the second power supply unit comprising a second coarse adjustment circuit configured to adjust output current of the second power supply unit; and a fine adjustment circuit communicatively coupled to the first and the second power supply units, the fine adjustment circuit configured to receive values indicative of the output currents of the first and the second power supply units; wherein the fine adjustment circuit further configured to calculate a difference in the values indicative of the output currents, compare the difference to a first threshold, and based on the difference being greater than the first threshold, compare the difference to a current step value, and the fine adjustment circuit configured to send a command to at least one of the first and the second power supply units to modify the output current, an amount of modification based on a relation of the difference in the values indicative of the output currents to the current step value; and wherein the at least one of the first and the second power supply units is configured to modify output current responsive to its respective coarse adjustment circuit, and configured to adjust output current responsive to the command from the fine adjustment circuit.