Active current sharing circuit

An active current sharing power system having a plurality of DC-DC converter modules, each having an input terminal to which an input DC voltage is coupled and an output terminal where the output DC voltage is provided, said converter modules being connected in parallel through their output terminals to a common bus connected to a load, each said converter module comprising:

• a buck converter for converting said input DC voltage to a regulated output DC voltage, said buck converter having a switch and an inductor connected in series between its respective input terminal and output terminal, said inductor having one end connected to its respective output terminal, a rectifier connected between said other end of said inductor and ground;
• and a capacitor connected between its respective output terminal and ground;
• a current sense circuit, coupled to said buck converter, for detecting the output current of said buck converter and for generating a current sense signal that is a function thereof;
• a reference circuit for generating a current share signal at a common current sharing bus that is a function of the current sense signals of each of said converter modules;
• and
• a control circuit coupled to said buck converter for adjusting the output power of said buck converter as a function of said buck converter's current sense signal and said current share signal.