Electronic apparatus and circuit board
AssigneeFujitsu Limited
InventorShoudu Yang
Life of this patent
Estimating the term…
Abstract
An electronic apparatus feeds a power to loads in response to a plurality of action modes. The electronic apparatus comprises a power source in the form of, e.g., an on/off controllable-DC/DC converter for providing a predetermined DC power as its output, a first switch circuit disposed on a power supply line extending from the power source to a first load, a second switch circuit disposed on a power supply line to a second load diverging from the input side of the first switch circuit, and a control circuit for providing an on/off control of the power source, the first switch circuit and the second switch circuit in response to the action modes.
Claims10
An electronic apparatus for feeding electric power to loads in response to a plurality of action modes, said electronic apparatus comprising:
- an on/off controllable power source circuit providing electric power as its output through a node to said loads;
- a first switch circuit disposed on a power supply line extending from said node to a first load, said first load including a CPU;
- a second switch circuit disposed on a power supply line to a second load also extending from the node, said second switch circuit not including any elements of said first switch circuit, and said second load including a memory;
- and
- a control circuit providing an on/off control of said power source circuit, said first switch circuit and said second switch circuit in response to said plurality of action modes;
- wherein said first switch circuit has two FETs having the same characteristics, the drains and sources of said two FETs being commonly connected in parallel into an electric power source line, and the gates thereof being commonly connected to a corresponding output of said control circuit;
- and
- wherein said second switch circuit has an FET having the same characteristics as the FETs of said first switch circuit, the drain and source of said second switch circuit FET being connected to the electric power source line, and the gate thereof being connected to a corresponding output of said control circuit.
A circuit board for feeding electric power from a power source circuit through a node to loads in response to a plurality of action modes, said circuit board comprising:
- a first switch circuit disposed on a first power supply line extending from said node to a first load, said first load including a CPU;
- a second switch circuit disposed on a second power supply line to a second load also extending from the node, said second switch circuit not including any elements of said first switch circuit, and said second load including a memory;
- and
- a control circuit providing an on/off control of said power source circuit, said first switch circuit and said second switch circuit in response to said plurality of action modes;
- wherein said first switch circuit has two FETs having the same characteristics, the drains and sources of said two FETs being commonly connected in parallel into an electric power source line, and the gates thereof being commonly connected to a corresponding output of said control circuit;
- and
- wherein said second switch circuit has an FET having the same characteristics as the FETs of said first switch circuit, the drain and source of said second switch circuit FET being connected to the electric power source line, and the gate thereof being connected to a corresponding output of said control circuit.
An electronic apparatus for feeding electric power to loads in response to a plurality of action modes, said electronic apparatus comprising:
- an on/off controllable power source circuit providing electric power as its output through a node to said loads;
- a first switch circuit disposed on a power supply line extending from said node to a first load;
- a second switch circuit disposed on a power supply line to a second load also extending from the node, said second switch circuit not including any elements of said first switch circuit;
- a control circuit providing an on/off control of said power source circuit, said first switch circuit and said second switch circuit in response to said plurality of action modes, wherein said control circuit in a first action mode turns on said power source circuit, said first switch circuit and said second switch circuit to permit a supply of electric power to said first and second loads, and wherein said control circuit in a second action mode turns on said power source circuit and said second switch circuit but not said first switch circuit to permit a supply of electric power to only said second load;
- and
- a third switch circuit disposed on a power supply line to a third load also extending from said node, said third switch circuit not including any elements of said first switch circuit, wherein said control circuit further provides an on/off control of said third switch circuit in response to said action modes;
- wherein said control circuit turns on both said power source circuit and said third switch circuit in a third action mode permitting a supply of electric power to said third load in the state of said first action mode, said second action mode or a stop mode;
- wherein said first switch circuit has two FETs having the same characteristics, the drains and sources of said two FETs being commonly connected in parallel into a power supply line, and the gates thereof being commonly connected to a corresponding output of said control circuit;
- and
- wherein said second switch circuit has an FET having the same characteristics as the FETs of said first switch circuit, the drain and source of said second switch circuit FET being connected to the power supply line, and the gate thereof being connected to a corresponding output of said control circuit.
Dependencies are inferred from the claim text.