Wireless load sharing for parallel power converters and method

Claim 2

A power supply including a virtual resistor, said power supply comprising: a power stage having an input for accepting unregulated power, an output for providing regulated power, a control input and a current sense output; a control circuit including an error amplifier having an inverting input coupled to said for providing regulated power output and an output coupled to said control input; a virtual resistance generator having an input coupled to said output of said error amplifier and an output coupled to a non inverting input of said error amplifier, said virtual resistance generator for supplying a reference voltage to said control circuit such that a voltage present at said output for providing regulated power as a function of current leaving said output for providing regulated power provides an output virtual resistance, said virtual resistance generator comprising a first resistor having a first end coupled to said input of said virtual resistance generator and a second end coupled to an inverting input of an operational amplifier; and a second resistor having a first end coupled to said inverting input of said operational amplifier and a second end coupled to an output of said operational amplifier, said first and second resistors setting a gain for said operational amplifier, said output of said operational amplifier being coupled to said non inverting input of said error amplifier via a third resistor.

Claim 3

A power supply as claimed in claim 1, wherein said control circuit comprises a voltage divider circuit having an input coupled to said output for providing regulated power and a divider output coupled to said inverting input of said error amplifier.

Claim 4

A power supply as claimed in claim 1, wherein said control circuit comprises: a comparator having an inverting input coupled to said output of said error amplifier; and a current sense input coupled to said current sense output, said current sense input being coupled to a non inverting input of said comparator, wherein an output of said comparator is coupled to said control input.

Claim 5

A power supply as claimed in claim 1, wherein said virtual resistance generator further comprises: a voltage reference generator for providing a reference voltage at an output; a voltage divider having an input coupled to said output of said voltage reference generator and having an output coupled to a non inverting input of said operational amplifier; and a resistor coupling said output of said voltage reference generator to said non inverting input of said error amplifier.

Claim 6

A power supply as claimed in claim 4, wherein said virtual resistance generator additionally comprises a capacitor having a first lead coupled to said non inverting input of said error amplifier and a second lead coupled to ground.

Claim 9

A method as claimed in claim 6, further comprising steps of: coupling said output signal from said error amplifier to said input of said virtual resistance generator; and providing an output signal from said virtual resistance generator to said non inverting input of said error amplifier.

Claim 10

A method as claimed in claim 7, further comprising steps of: coupling an inverting input of an operational amplifier to said input of said virtual resistance generator; setting a gain for said operational amplifier by providing a ratio of resistor values; and coupling an output signal from said operational amplifier to said non inverting input of said error amplifier.

Claim 11

A method as claimed in claim 8, further comprising steps of: providing a reference voltage generator having an output for providing reference output voltage; and coupling said reference output voltage to a non inverting input of said operational amplifier.

Claim 12

A method as claimed in claim 9, wherein said step of coupling said reference output voltage includes steps of: providing a resistive voltage divider having an input and a divided voltage output; coupling said input of said resistive voltage divider to said output of said reference voltage generator; and coupling said divided voltage output to said non inverting input of said operational amplifier.

Claim 13

A method as claimed in claim 10, further comprising a step of coupling said output of said reference voltage generator to said non inverting input of said error amplifier.

Claim 14

A power supply including a virtual resistor, said power supply comprising: a power stage having an input for accepting unregulated power, an output for providing regulated power, a control input and a current sense output; a control circuit including an error amplifier having an inverting input coupled to said output for providing regulated power and an output coupled to said control input, wherein said control circuit comprises a voltage divider circuit having an input coupled to said output for providing regulated power, a divider output coupled to an inverting input of said error amplifier, a comparator having an inverting input coupled to said output of said error amplifier, a current sense input coupled to said current sense output, said current sense input being coupled to a non inverting input of said comparator, wherein an output of said comparator is coupled to said control input; and a virtual resistance generator having an input coupled to said output of said error amplifier and an output coupled to a non inverting input of said error amplifier, said virtual resistance generator for supplying a reference voltage to said control circuit such that a voltage present at said output for providing regulated power as a function of current leaving said output for providing regulated power provides an output virtual resistance, said virtual resistance generator comprising a first resistor having a first end coupled to said input of said virtual resistance generator and a second end coupled to an inverting input of an operational amplifier, a second resistor having a first end coupled to said inverting input of said operational amplifier and a second end coupled to an output of said operational amplifier, said first and second resistors setting a gain for said operational amplifier, said output of said operational amplifier being coupled to said non inverting input of said error amplifier via a third resistor.

Claim 15

A power supply including a virtual resistor, said power supply comprising: a power stage having an input for accepting unregulated power, an output for providing regulated power, a control input and a current sense output; a control circuit including an error amplifier having an inverting input coupled to said output for providing regulated power and an output coupled to said control input, wherein said control circuit comprises a voltage divider circuit having an input coupled to said output for providing regulated power, a divider output coupled to an inverting input of said error amplifier, a comparator having an inverting input coupled to said output of said error amplifier, a current sense input coupled to said current sense output, said current sense input being coupled to a non inverting input of said comparator, wherein an output of said comparator is coupled to said control input; and a virtual resistance generator having an input coupled to said output of said error amplifier and an output coupled to a non inverting input of said error amplifier, said virtual resistance generator for supplying a reference voltage to said control circuit such that a voltage present at said output for providing regulated power as a function of current leaving said output for providing regulated power provides an output virtual resistance, said virtual resistance generator comprising a first resistor having a first end coupled to said input of said virtual resistance generator and a second end coupled to an inverting input of an operational amplifier, a second resistor having a first end coupled to said inverting input of said operational amplifier and a second end coupled to an output of said operational amplifier, said first and second resistors setting a gain for said operational amplifier, said output of said operational amplifier being coupled to said non inverting input of said error amplifier via a third resistor.

Claim 16

A power supply as claimed in claim 12, wherein said virtual resistance generator further comprises: a voltage reference generator for providing a reference voltage at an output; a voltage divider having an input coupled to said output of said voltage reference generator and having an output coupled to a non inverting input of said operational amplifier; and a resistor coupling said output of said voltage reference generator to said non inverting input of said error amplifier.

Claim 17

A power supply as claimed in claim 13, wherein said virtual resistance generator additionally comprises a capacitor having a first lead coupled to said non inverting input of said error amplifier and a second lead coupled to ground.

Claim 18

A power supply including a virtual resistor, said power supply comprising: a power stage having an input for accepting unregulated power, an output for providing regulated power, a control input and a current sense output; a control circuit including an error amplifier having an inverting input coupled to said output for providing regulated power and an output coupled to said control input, wherein said control circuit comprises a voltage divider circuit having an input coupled to said output for providing regulated power and a divider output coupled to said inverting input of said error amplifier, wherein said control circuit comprises: a comparator having an inverting input coupled to said output of said error amplifier; and a current sense input coupled to said current sense output, said current sense input being coupled to a non inverting input of said comparator, wherein an output of said comparator is coupled to said control input; and a virtual resistance generator having an input coupled to said output of said error amplifier and an output coupled to a non inverting input of said error amplifier, said virtual resistance generator for supplying a reference voltage to said control circuit such that a voltage present at said output for providing regulated power as a function of current leaving said output for providing regulated power provides an output virtual resistance, wherein said virtual resistance generator comprises: a first resistor having a first end coupled to said input of said virtual resistance generator and a second end coupled to an inverting input of an operational amplifier; and a second resistor having a first end coupled to said inverting input of said operational amplifier and a second end coupled to an output of said operational amplifier, said first and second resistors setting a gain for said operational amplifier, said output of said operational amplifier being coupled to said non inverting input of said error amplifier via a third resistor.

Claim 19

A power supply including a virtual resistor, said power supply comprising: a power stage having an input for accepting unregulated power, an output for providing regulated power, a control input and a current sense output; a control circuit including an error amplifier having an inverting input coupled to said output for providing regulated power and an output coupled to said control input, wherein said control circuit comprises a voltage divider circuit having an input coupled to said output for providing regulated power and a divider output coupled to said inverting input of said error amplifier, wherein said control circuit comprises: a comparator having an inverting input coupled to said output of said error amplifier; and a current sense input coupled to said current sense output, said current sense input being coupled to a non inverting input of said comparator, wherein an output of said comparator is coupled to said control input; and a virtual resistance generator having an input coupled to said output of said error amplifier and an output coupled to a non inverting input of said error amplifier, said virtual resistance generator for supplying a reference voltage to said control circuit such that a voltage present at said output for providing regulated power as a function of current leaving said output for providing regulated power provides an output virtual resistance, wherein said virtual resistance generator comprises: a first resistor having a first end coupled to said input of said virtual resistance generator and a second end coupled to an inverting input of an operational amplifier; and a second resistor having a first end coupled to said inverting input of said operational amplifier and a second end coupled to an output of said operational amplifier, said first and second resistors setting a gain for said operational amplifier, said output of said operational amplifier being coupled to said non inverting input of said error amplifier via a third resistor.

Claim 20

A power supply as claimed in claim 15, wherein said virtual resistance generator further comprises: a voltage reference generator for providing a reference voltage at an output; a voltage divider having an input coupled to said output of said voltage reference generator and having an output coupled to a non inverting input of said operational amplifier; and a resistor coupling said output of said voltage reference generator to said non inverting input of said error amplifier.

Claim 21

A power supply as claimed in claim 16, wherein said virtual resistance generator additionally comprises a capacitor having a first lead coupled to said non inverting input of said error amplifier and a second lead coupled to ground.