Fault detection on a dual supply system for a universal serial bus system
First Claim
1. A universal serial bus apparatus comprising:
- a universal serial bus controller;
an upstream port which is connected to the universal serial bus controller, the upstream port having a power line that supplies the universal serial bus controller with power;
at least one downstream port which is connected to the universal serial bus controller;
a power supply having a source of power, the power supply connected to the at least one downstream port for supplying power to the at least one downstream port, the power supply separate from the power line and having a signal indicating the amount of current drawn by the power supply; and
a fault detect circuit connected to the universal serial bus controller and connected to the source of power for the power supply for indicating an overcurrent or thermal error to the universal serial bus controller and for turning on the power supply.
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Accused Products
Abstract
A method and apparatus for a dual power supply on a universal serial bus system using an overcurrent detect circuit. Dual power supplies in the universal serial bus system allows for greater flexibility of operation and is based on two separate power systems. The first power system is achieved using the power line on the bus connecting to the universal serial bus controller. The second power system is a separate power supply to power the downstream ports. Moreover, the universal serial bus system has an overcurrent and thermal error detect circuit based on the power system in order to achieve an efficient and cost effective method and apparatus in which to notify the universal serial bus controller of any error in the power system.
92 Citations
47 Claims
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1. A universal serial bus apparatus comprising:
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a universal serial bus controller; an upstream port which is connected to the universal serial bus controller, the upstream port having a power line that supplies the universal serial bus controller with power; at least one downstream port which is connected to the universal serial bus controller; a power supply having a source of power, the power supply connected to the at least one downstream port for supplying power to the at least one downstream port, the power supply separate from the power line and having a signal indicating the amount of current drawn by the power supply; and a fault detect circuit connected to the universal serial bus controller and connected to the source of power for the power supply for indicating an overcurrent or thermal error to the universal serial bus controller and for turning on the power supply. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A universal serial bus apparatus comprising:
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a universal serial bus controller; at least one downstream port connected to the universal serial bus controller; a first power source connected to the universal serial bus controller; a second power source connected to the at least one downstream port, the second power being independent from the first power source; an overcurrent or thermal fault signal generated by the second power source; and a fault detect circuit connected to the fault signal and to the second power source, the fault detect circuit indicating to the universal serial bus controller an error. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A universal serial bus apparatus comprising:
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a universal serial bus controller; at least one downstream port connected to the universal serial bus controller; a first power source connected to the universal serial bus controller; a second power source connected to the at least one downstream port, the second power source having an overcurrent signal indicating the overcurrent status of the second power source; and an overcurrent detect circuit connected to the overcurrent signal, to the first power source and to the second power source, the overcurrent detect circuit including a delay circuit and indicating to the universal serial bus controller an overcurrent when the first power source and second power source have power and when the overcurrent signal indicates an overcurrent condition. - View Dependent Claims (14, 15, 16)
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17. A universal serial bus apparatus comprising:
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a universal serial bus controller; at least one downstream port connected to the universal serial bus controller; a first power source connected to the universal serial bus controller; a second power source connected to the at least one downstream port; and fault detect circuitry connected to the first power source and to the second power source, the fault detect circuitry including means for determining the sufficiency of power from the first power source and means for transferring power from the second power source to the universal serial bus controller in the event that the power from the first power source falls below a predetermined value. - View Dependent Claims (18, 19, 20)
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21. A universal serial bus apparatus comprising:
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a universal serial bus controller; a first power source; a second power source; a first means for determining whether the first power source or the second power source powers the universal serial bus controller, the first means connected to the first power source and the second power source, the first means also connected to the universal serial bus controller. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29)
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30. A compound universal serial bus apparatus comprising:
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a universal serial bus controller; an upstream port which is connected to the universal serial bus controller, the upstream port having a power line that supplies the universal serial bus controller with power; at least one downstream port which is connected to the universal serial bus controller; an external device which is connected to the universal serial bus controller; a power supply connected to the at least one downstream port for supplying power to the at least one downstream port, the power supply separate from the power line and having a signal indicating the amount of current drawn by the power supply; and a fault detect circuit connected to the universal serial bus controller and connected to the power supply for indicating an overcurrent or thermal error to the universal serial bus controller and for turning on the power supply. - View Dependent Claims (31, 32, 33, 34)
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35. A method of powering a universal serial bus controller and at least one port downstream of the universal serial bus controller, the universal serial bus controller having one power source via a line on a bus and the at least one port downstream of the universal serial bus controller having a second power source separate from the first power source, the method comprising the steps of:
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connecting the universal serial bus controller to the bus; powering the universal serial bus controller, but not powering the at least one downstream port, via the bus; connecting the second power source to the downstream ports; and delaying the powering of the at least one downstream port via the second power source until after connecting the universal serial bus controller to the bus, powering the universal serial bus controller, and connecting the second power source to the at least one downstream port. - View Dependent Claims (36, 37, 38)
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39. A method for determining an overcurrent or thermal error condition in a universal serial bus system, the method comprising the steps of:
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sensing a signal on a power subsystem in the universal serial bus system, the signal indicating an overcurrent or a thermal error and the signal not being a voltage input or a voltage output of the power subsystem; determining whether the power subsystem is powered; delaying the sending of the determination of whether the system is powered; and notifying the universal serial bus system of the overcurrent or the thermal error after the steps of sensing of the signal on the power subsystem, determining whether the power subsystem is powered and delaying the sending of the determination of whether the system is powered. - View Dependent Claims (40)
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41. A method for determining an overcurrent condition in a universal serial bus system, the method comprising the steps of:
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sensing a signal on a line in a power subsystem of the universal serial bus system, the signal indicating an overcurrent or a thermal error and the signal not being the voltage input or voltage output of the power subsystem; comparing the signal with a value to determine whether an overcurrent or thermal error has occurred; delaying the sending of the determination of whether the system is powered; and notifying the universal serial bus system of an overcurrent or a thermal error after the steps of sensing of the signal on a power subsystem, comparing the signal with a value to determine whether an overcurrent or thermal error has occurred and delaying the sending of the determination of whether the system is powered.
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42. A method for powering a universal serial bus system, the method comprising the steps of:
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powering a universal serial bus controller with a first power source; powering at least one downstream port which is connected to the universal serial bus controller with a second power source; switching the power to the universal serial bus controller from the first power source to the second power source when the voltage on the first power source is less than a predetermined value. - View Dependent Claims (43, 44, 45, 46, 47)
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Specification