US Patent 7170765 Current distribution circuit

A current distribution circuit for parallel power supplies is provided. The parallel power supplies include at least a first power supply and a second power supply, and the current distribution circuit includes a voltage amplifier, a power converting unit, a detecting unit, an equivalent diode, an adjustable amplifier, an adder and an active droop unit. The operating voltage reference of the active droop unit is linearly adjusted for reducing an error resulting from the first power supply and the second power supply while the load is less than a pre-determined value.