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US 2003/0151445 A1Published application
In-rush current protection
AssigneeADC DSL Systems, Inc.
InventorGeorge Bertran Dodson III
Life of this patent
Estimating the term…
Abstract
A circuit for controlling inrush current to a load is provided. The circuit includes a variable impedance device having a control input. The variable impedance device is coupled between a power supply interface and a load interface. The circuit also includes a control circuit coupled to the control input of the variable impedance device and also coupled to the load interface. The control circuit is adapted to provide a signal at the control input of the variable impedance device which results in a linear increase in applied voltage to the load when the circuit is coupled to an input power source. A resistor is coupled between the first and second terminals of the power supply interface to provide a current discharge path for the control circuit when the circuit is disconnected from the power supply.
Claims29
A circuit for controlling inrush current to a load, the circuit comprising:
- a power supply interface having first and second nodes adapted to be coupled to first and second terminals of a power supply;
- a load interface having first and second nodes, adapted to be coupled to the load;
- a variable impedance device having a control input, the variable impedance device coupled between the power supply interface and the load interface, the variable impedance device including a controllable current path between the power supply interface and the load interface;
- a control circuit coupled to the control input of the variable impedance device and also coupled to the second node of the load interface, wherein the control circuit is adapted to provide a signal at the control input of the variable impedance device that causes a linear increase in voltage applied to the load when the power supply interface is coupled to a power supply;
- and
- a resistor, coupled between the first and second nodes of the power supply interface to provide a current discharge path for the control circuit when the circuit is disconnected from the first and second terminals of the power supply.
3 more elements
A circuit for controlling inrush current to a load, the circuit comprising:
- a power supply interface having first and second nodes adapted to be coupled to first and second terminals of a power supply;
- a load interface having first and second nodes, adapted to be coupled to the load;
- a variable impedance device having a control input, the variable impedance device coupled between the power supply interface and the load interface, the variable impedance device including a controllable current path between the power supply interface and the load interface;
- an RC circuit, including a first resistor coupled in series with a first capacitor, the first resistor also coupled to the control input of the variable impedance device and the first capacitor also coupled to the second node of the load interface;
- a second capacitor, coupled between the control input and the second node of the power supply interface;
- a voltage regulating circuit, coupled to the control input of the variable impedance device, that limits the voltage on the control input to a steady state level;
- and
- a second resistor, coupled between the first and second nodes of the power supply interface to provide a current discharge path for the first and second capacitors and the load when the circuit is disconnected from the first and second terminals of the power supply.
5 more elements
A circuit for controlling inrush current to a load, the circuit comprising:
- a power supply interface having first and second nodes adapted to be coupled to first and second terminals of a power supply;
- a load interface having first and second nodes, adapted to be coupled to the load;
- a field effect transistor having a gate, the transistor coupled between the power supply interface and the load interface, the transistor including a channel coupled between the power supply interface and the load interface;
- an RC circuit, including a first resistor coupled in series with a first capacitor, the first resistor also coupled to the control input of the variable impedance device and the first capacitor also coupled to the second node of the load interface;
- a second capacitor, coupled between the control input and the second node of the power supply interface;
- a zener diode, coupled to the second node of the power supply interface and an intermediate node;
- a second resistor, coupled between the intermediate node and the control input of the transistor;
- a third resistor, coupled between the first node of the power supply interface and the intermediate node;
- wherein the zener diode limits the voltage on the control input to a selected steady state level;
- and
- a fourth resistor, coupled between the first and second nodes of the power supply interface to provide a current discharge path for the first and second capacitors and the load when the circuit is disconnected from the first and second terminals of the power supply.
8 more elements
An electronic module, the module comprising:
- a power supply interface having first and second nodes adapted to be coupled to first and second terminals of a power supply;
- a functional circuit having first and second nodes;
- and
- a circuit for controlling inrush current coupled to the first and second nodes of the functional circuit, the inrush control circuit comprising:
- a variable impedance device having a control input, the variable impedance device coupled between the power supply interface and the functional circuit, the variable impedance device including a controllable current path between the power supply interface and the functional circuit,
- an RC circuit, including a first resistor coupled in series with a first capacitor, the first resistor also coupled to the control input of the variable impedance device and the first capacitor also coupled to the second node of the functional circuit,
- a second capacitor, coupled between the control input and the second node of the power supply interface,
- a voltage regulating circuit, coupled to the control input of the variable impedance device, that limits the voltage on the control input to a steady state level, and
- a second resistor, coupled between the first and second nodes of the power supply interface to provide a current discharge path for the first and second capacitors and the functional circuit when the electronic module is disconnected from the first and second terminals of the power supply.
6 more elements
A method for hot plugging an electronic module, the method comprising:
- plugging a power supply interface of the electronic module into a power supply;
- controllably turning on a variable impedance device when the electronic module is plugged into the power supply to limit inrush current provided to a functional circuit on the electronic module and to provide a linearly increasing voltage applied to the functional circuit;
- limiting the voltage on the control input to a selected steady state level;
- and
- discharging the voltage on the control input through a resistor when the electronic module is disconnected from the power supply.
2 more elements
A circuit for controlling inrush current to a load, the circuit comprising:
- a variable impedance device having a control input;
- the variable impedance device is coupled between a power supply interface and a load interface;
- a control circuit coupled to a control input of the variable impedance device and also coupled to the load interface;
- the control circuit adapted to linearly increase a signal at the control input of the variable impedance device when the power supply interface is coupled to a power supply;
- and
- a resistor coupled between the first and second terminals of the power supply interface to provide a current discharge path for the control circuit when the circuit is disconnected from the power supply.
3 more elements
A circuit for controlling inrush current to a load, the circuit comprising:
- a first node adapted to be coupled to a first power supply terminal;
- a second node adapted to be coupled to a second power supply terminal;
- a variable impedance device having a control input, the variable impedance device coupled to the second node and to the load, the variable impedance device including a controllable current path between the second node and the load;
- a control circuit coupled to the control input of the variable impedance device and also coupled to the load, that provides a linear change in the voltage across the load upon application of power across the first and second nodes;
- and
- a resistor, coupled between the first and second nodes to provide a current discharge path for the control circuit and the load when the circuit is disconnected from the first and second power supply terminals.
3 more elements
Dependencies are inferred from the claim text.