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US6465909B1 Expired / Lapsed US ⏱️ 0.0 years remaining

Circuits and methods for controlling load sharing by multiple power supplies

Assignee: Analog Devices International ULC
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Filing: 2000-07-31
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Granted: 2002-10-15
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Expires: 2020-07-31
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Abstract

Abstract Circuits and methods for controlling load sharing by multiple power supplies are provided. In preferred embodiments, load share controllers utilize multiple voltage control loops to monitor the output voltages that are being provided by multiple power supplies connected to a load. These voltage control loops each generate a voltage control voltage that is proportional to the difference between the actual output voltage of the corresponding power supply and the desired output voltage. The voltage control loop with the highest voltage control voltage then controls a current control voltage generated in a current control loop for each power supply via a share bus. These current control loops then regulate the current provided by the corresponding power supplies so that those currents are all proportional to the voltage on the share bus. By monitoring the current control voltage in each current control loop, the voltage at the output of each power supply, and the direction of the current flowing between each power supply and the load, the circuits and methods of preferred embodiments of the invention can detect and account for out-of-regulation conditions, over voltage conditions, short circuit conditions, and hot-swapping conditions.

Inventors

  • 👤 David Henry Soo
  • 👤 Robert Loren Reay

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 01:37
CPC Classifications
H; H02; H02J; H02J1/00; H02J1/10; H02J1/102; H02J1/001; H02H; H02H9/00; H02H9/001; H02H9/004

Claims Analysis

Total Claims: 30
Claim 1
Independent Claim 132 words
A circuit for controlling load sharing by a plurality of power supplies that are providing power to a load, comprising: a first error amplifier that measures an output voltage provided by one of the plurality of power supplies to the load; a diode that is couple to the output of the first error amplifier and that provides a voltage control voltage that is proportional to the output voltage of the one of the plurality of power supplies on a share bus; an amplifier that measures an output current provided by the one of the plurality of power supplies to the load; a second error amplifier that provides a feedback signal to the one of the plurality of power supplies based upon a comparison of the voltage control voltage and the output current.
Claim 2
Dependent Claim 132 words
A circuit for controlling load sharing by a plurality of power supplies that are providing power to a load, comprising: a first error amplifier that measures an output voltage provided by one of the plurality of power supplies to the load; a diode that is couple to the output of the first error amplifier and that provides a voltage control voltage that is proportional to the output voltage of the one of the plurality of power supplies on a share bus; an amplifier that measures an output current provided by the one of the plurality of power supplies to the load; a second error amplifier that provides a feedback signal to the one of the plurality of power supplies based upon a comparison of the voltage control voltage and the output current.
Claim 3
Dependent Claim 29 words
The circuit of claim 1 , further comprising a status output that indicates when the one of the plurality of power supplies is operating outside of a given range.
Claim 4
Dependent Claim 51 words
The circuit of claim 2 , further comprising a timer that suspends indication of when the one of the plurality of power supplies is operating outside of the given range until the one of the power supplies has been operating outside of the given range for a given period of time.
Claim 5
Dependent Claim 45 words
The circuit of claim 2 , further comprising a logic circuit that suspends indication of when the one of the plurality of power supplies is operating outside of the given range when the one of the power supplies is providing current below a given level.
Claim 6
Dependent Claim 104 words
The circuit of claim 1 , further comprising: a comparator that detects when the output voltage of the one of the plurality of power supplies exceeds a given voltage; a gate driver that causes the output current provided by the one of the plurality of power supplies to be reduced, and, once the output current provided by the one of the plurality of power supplies has dropped below a given level, causes the output current provided to increase to a desired level; and a regulator that regulates the output voltage provided by the one of the plurality of power supplies at the desired level.
Claim 7
Dependent Claim 50 words
The circuit of claim 5 , further comprising a timer that shuts down current flow from the one of the plurality of power supplies to the load after the output voltage provided by the one of the plurality of power supplies has been regulated for a given period of time.
Claim 8
Dependent Claim 35 words
The circuit of claim 5 , further comprising a status output that indicates a fault condition upon detecting when the output voltage of the one of the plurality of power supplies exceeds the given voltage.
Claim 9
Dependent Claim 46 words
The circuit of claim 1 , further comprising: a comparator that detects a reverse current flow into one of the plurality of power supplies; and a logic circuit that isolates the one of the plurality of power supplies after the reverse current flow has been detected.
Claim 10
Dependent Claim 35 words
The circuit of claim 8 , further comprising a timer that confirms that the reverse current flow is present for a given period of time before isolating the one of the plurality of power supplies.
Claim 11
Dependent Claim 31 words
The circuit of claim 8 , further comprising a status output that indicates a fault when the output voltage of the one of the power supplies drops below a given voltage.
Claim 12
Dependent Claim 61 words
The circuit of claim 1 , further comprising: a comparator that detects when the output voltage of one of the plurality of power supplies has fallen below a given level; and a logic circuit that isolates the one of the plurality of power supplies after detecting that the one of the plurality of power supplies has fallen below the given level.
Claim 13
Dependent Claim 31 words
The circuit of claim 11 , further comprising a status output that indicates a fault when the output voltage of the one of the power supplies drops below the given level.
Claim 14
Dependent Claim 48 words
The circuit of claim 11 , further comprising a timer that prevents the one of the plurality of power supplies from providing power to the load for a given period of time after the output voltage of the one of the plurality of power supplies has been restored.
Claim 15
Dependent Claim 44 words
The circuit of claim 11 , further comprising a gate driver that ramps up current provided from the one of the plurality of power supplies to the load after the output voltage of the one of the plurality of power supplies has been restored.
Claim 16
Independent Claim 104 words
A method for controlling load sharing by a plurality of power supplies that are providing power to a load, comprising: measuring an output voltage provided by one of the plurality of power supplies to the load; providing a voltage control voltage that is proportional to the output voltage of the one of the plurality of power supplies on a share bus; measuring an output current provided by the one of the plurality of power supplies to the load; providing a feedback signal to the one of the plurality of power supplies based upon a comparison of the voltage control voltage and the output current.
Claim 17
Independent Claim 104 words
A method for controlling load sharing by a plurality of power supplies that are providing power to a load, comprising: measuring an output voltage provided by one of the plurality of power supplies to the load; providing a voltage control voltage that is proportional to the output voltage of the one of the plurality of power supplies on a share bus; measuring an output current provided by the one of the plurality of power supplies to the load; providing a feedback signal to the one of the plurality of power supplies based upon a comparison of the voltage control voltage and the output current.
Claim 18
Dependent Claim 25 words
The method of claim 15 , further comprising indicating when the one of the plurality of power supplies is operating outside of a given range.
Claim 19
Dependent Claim 48 words
The method of claim 16 , further comprising suspending indication of when the one of the plurality of power supplies is operating outside of the given range until the one of the power supplies has been operating outside of the given range for a given period of time.
Claim 20
Dependent Claim 41 words
The method of claim 16 , further comprising suspending indication of when the one of the plurality of power supplies is operating outside of the given range when the one of the power supplies is providing current below a given level.
Claim 21
Dependent Claim 93 words
The method of claim 15 , further comprising: detecting when the output voltage of the one of the plurality of power supplies exceeds a given voltage; causing the output current provided by the one of the plurality of power supplies to be reduced; once the output current provided by the one of the plurality of power supplies has dropped below a given level, allowing the output current provided to increase to a desired level; and regulating the output voltage provided by the one of the plurality of power supplies at the desired level.
Claim 22
Dependent Claim 47 words
The method of claim 19 , further comprising shutting down current flow from the one of the plurality of power supplies to the load after the output voltage provided by the one of the plurality of power supplies has been regulated for a given period of time.
Claim 23
Dependent Claim 31 words
The method of claim 19 , further comprising indicating a fault condition upon detecting when the output voltage of the one of the plurality of power supplies exceeds the given voltage.
Claim 24
Dependent Claim 40 words
The method of claim 15 , further comprising: detecting a reverse current flow into the one of the plurality of power supplies; and isolating the one of the plurality of power supplies after the reverse current flow has been detected.
Claim 25
Dependent Claim 32 words
The method of claim 22 , further comprising confirming that the reverse current flow is present for a given period of time before isolating the one of the plurality of power supplies.
Claim 26
Dependent Claim 27 words
The method of claim 22 , further comprising indicating a fault when the output voltage of the one of the power supplies drops below a given voltage.
Claim 27
Dependent Claim 55 words
The method of claim 15 , further comprising: detecting when the output voltage of the one of the plurality of power supplies has fallen below a given level; and isolating the one of the plurality of power supplies after detecting that the one of the plurality of power supplies has fallen below the given level.
Claim 28
Dependent Claim 27 words
The method of claim 25 , further comprising indicating a fault when the output voltage of the one of the power supplies drops below the given level.
Claim 29
Dependent Claim 45 words
The method of claim 25 , further comprising preventing the one of the plurality of power supplies from providing power to the load for a given period of time after the output voltage of the one of the plurality of power supplies has been restored.
Claim 30
Dependent Claim 40 words
The method of claim 25 , further comprising ramping up current provided from the one of the plurality of power supplies to the load after the output voltage of the one of the plurality of power supplies has been restored.

References Cited (Backward Citations)

US4318007A Cited
DE3804074A1 Cited
EP0402367A1 Cited
US5157269A Cited
US6166455A Cited
US6215290B1 Cited
US6236582B1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2005-10-14 2006-04-15 2006-10-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2009-10-14 2010-04-15 2010-10-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2013-10-14 2014-04-15 2014-10-15 $7700.00 Window Closed / Lapsed

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