Active impendance current-share method

• US 7,282,899 B1
• Filed: 06/09/2006
• Issued: 10/16/2007
• Est. Priority Date: 06/09/2006
• Status: Expired due to Fees

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Daun-Lindberg, Timothy C., Hruby, Brian J.
• Primary Examiner(s): BERHANE, ADOLF D
• Application Number:
  US11/423,331
• Time in Patent Office: 494 Days
• Field of Search: 323/268, 323/271, 323/272, 323/280, 323/282, 323/285
• US Class Current: 323/272
• CPC Class Codes: G05F 3/185 and field-effect transistors
• CPC Class Codes: H02J 1/001 Hot plugging or unplugging of load or power modules to or from power distribution networks
• CPC Class Codes: H02J 1/10 Parallel operation of dc sources

Abstract

Exemplary embodiments include An active impedance current-sharing circuit including: a power supply in electrical communication with a current sense resistor; a differential amplifier in electrical communication with the current sense resistor; a gate adjust amplifier in electrical communication with the differential amplifier; an ORing MOSFET in electrical communication with the gate adjust amplifier and the current sense resistor; a current share resistor in electrical communication with a current share bus and the gate adjust amplifier; and a current share output in electrical communication with the ORing MOSFET, wherein the circuit allows two or more power supplies that are not designed for current share to be connected in parallel and current share by actively modulating the ORing MOSFET between its linear and fully enhanced regions.

Claims

1. An active impedance current-sharing circuit comprising:

a power supply in electrical communication with a current sense resistor;

a differential amplifier in electrical communication with the current sense resistor;

a gate adjust amplifier in electrical communication with the differential amplifier;

an ORing MOSFET operating in its linear region in electrical communication with the gate adjust amplifier and the current sense resistor;

a current share resistor in electrical communication with a current share bus and the gate adjust amplifier; and

a current share output in electrical communication with the ORing MOSFET,

wherein the circuit allows two or more power supplies that are not designed for current share to be connected in parallel and current share by actively modulating the ORing MOSFET between its linear and fully enhanced regions;

wherein pole-zero compensation is utilized to modify a bandwidth of a response for stability and speed in aiding the circuit in recovering from transient conditions;

wherein voltage across the current share resistor indicates whether the current share output is sourcing less than or greater than 50% of a load current; and

wherein the current share bus is equal to half of the load current.

2. The circuit of claim 1, wherein the differential amplifier is used to sense the current across the current sense resistor.

3. The circuit of claim 2, wherein the gate adjust amplifier is used to adjust a gate of the ORing MOSFET between a linear region and a saturation region and the ORing MOSFET behaves as an analog device.

4. The circuit of claim 3, wherein the gate adjust amplifier compares a load current of the power supply to the current share bus.

5. The circuit of claim 4, further comprising a current share comparator in electrical communication with the ORing MOSFET.