Power balancing between two power rails

A power controller, comprising:

• a first power supply rail at a first voltage, a second power supply rail at a second voltage, and an output rail;
• a first buck controller having an input coupled to the first power supply rail and an output coupled to the output rail;
• a second buck controller having an input coupled to the second power supply rail, having an reference voltage input, and having an output coupled to the output rail;
• and
• a power balancer having an average current input coupled to the outputs of the first and second buck controllers, and having a reference voltage output coupled to the reference voltage input, the power balancer including:
• a resistor ladder having outputs, and
• a multiplexer having inputs coupled to the resistor ladder outputs, a command input, and the reference voltage output.

A power controller, comprising:

• a first power supply rail at a first voltage, a second power supply rail at a second voltage, and an output rail;
• a first buck controller having an input coupled to the first power supply rail and having an output coupled to the output rail;
• a second buck controller having an input coupled to the second power supply rail, having an reference voltage input, and having an output coupled to the output rail;
• a power balancer having an average current input coupled to the outputs of the first and second buck controllers and having a reference voltage output;
• and
• a filter coupling the reference voltage output to the reference voltage input.

A method comprising:

• receiving on an input of a first buck controller a first power supply rail at a first voltage and generating on an output of the first buck controller a first voltage coupled to an output rail;
• receiving on an input of a second buck controller a second power supply rail at a second voltage different from the first voltage, receiving a reference voltage on an input of the second buck controller, and generating on an output of the second buck controller a second voltage coupled to the output rail;
• and
• generating the reference voltage based on an average current output by the first and second buck controllers by combining the outputs of the first and second buck controllers between a first and a second resistor of an isolation circuit;
• the first buck controller functioning as a voltage source for the output power rail and the second buck controller controlling, based on the reference voltage, an amount of current in the output power rail received from each of the first and second buck controllers, so that differing currents in the first and second buck controllers generates a power in both input rails that is balanced.

A method comprising:

• receiving on an input of a first buck controller a first voltage and generating on an output of the first buck controller a first voltage coupled to an output rail;
• receiving on an input of a second buck controller a second voltage different from the first voltage, receiving a reference voltage on an input of the second buck controller, and generating on an output of the second buck controller a second voltage coupled to the output rail;
• and
• generating to the reference voltage input a reference voltage based on an average current output by the first and second buck controllers by combining the outputs of the first and second buck controllers between a first and second resistor of an isolation circuit, the generating the reference voltage includes receiving input signals in a multiplexer and selecting the reference voltage from one of the multiplexer input signals;
• and
• the first buck controller functioning as a voltage source for the output power rail and the second buck controller controlling, based on the reference voltage, an amount of current in the output power rail received from each of the first and second buck controllers.

A system comprising:

• a first buck controller having an input coupled to a first power rail at a first voltage and having an output that is coupled to an output rail;
• a first current sensor having an input coupled to the output of the first buck controller and having an output;
• a second buck controller having an input coupled to a second power rail at a second voltage, having a reference voltage input, and having an output that is coupled to the output rail;
• a second current sensor having an input coupled to the output of the second buck controller and having an output;
• an isolation circuit coupled to the outputs of the first and second current sensors and having an output;
• and
• a power balancer having an input coupled to the output of the isolation circuit, having a command input, and having a reference voltage output coupled to the reference voltage input.