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US 6,184,742 B2Granted
Current distribution circuit having an additional parallel DC-current sinking branch
AssigneeU.S. Philips Corporation
InventorsJacob Mulder, Fransiscus J. M. Thus, Eric C. Labbe
Life of this patent
Estimating the term…
Abstract
A current distribution circuit for application in a communication device, such as a telephone subscriber circuit comprises a first current sinking branch, which is connected in parallel to a second current sinking branch. Both branches sink at least the DC current on the telephone line, whereas an excess current in the DC line is taken up by the second current sinking branch, which is provided with a current sinking transistor, whose collector/emitter voltage is relatively large. This leads to a reduced effectively needed chip area. The DC line-current can be measured by means of a low pass filter, preferable connected to a current mirror means.
Claims16
A current distribution circuit comprising:
- a first current sinking branch, which is provided with a series arrangement of a main current stream of a first controlled semiconductor having a first control input, and of a circuit for providing a DC supply voltage,
- a second current sinking branch connected in parallel to the series arrangement, which second current sinking branch is provided with a second control input, wherein the first and second current sinking branches support at least DC current,
- means for controlling currents through the first and second current sinking branches, which controlling means is coupled between the first and second control inputs, and
- an at least DC current measuring means for providing a measure for at least a DC-current in the first current sinking branch, the at least DC current measuring means being coupled between the first control input and the controlling means, the second control input being connected to an output of the controlling means, and the controlling means being arranged to control leading an excessive part of at least the DC-current in the main current stream through the second current sinking branch, the first and second current sinking branches thereby substantially distributing a total current provided to the current distribution circuit.
1 more element
A telecommunication device with a current distribution circuit, said current distribution circuit comprising:
- a first current sinking branch including a main current stream of a first controlled semiconductor device, said first current sinking branch having a first control input;
- a second current sinking branch connected in parallel to the first current sinking branch, said second current sinking branch having a second control input, said first and second current sinking branches being DC and AC current sinking branches;
- means for controlling DC and AC currents through said first and second current sinking branches, said controlling means being coupled to said first and second control inputs, and
- an at least DC current measuring means coupled to the controlling means for providing a measure for at least a DC-current in said first current sinking branch, said second control input being connected to said controlling means for leading an excessive part of at least said DC-current through the second current sinking branch.
1 more element
A telecommunication device comprising:
- a current distribution circuit including:
- a first current sinking branch, which is provided with a series arrangement of a main current stream of a first controlled semiconductor having a first control input, and of a circuit for providing a DC supply voltage,
- a second current sinking branch connected in parallel to the series arrangement, which second current sinking branch is provided with a second control input, wherein the first and second branches support at least DC current;
- means for controlling currents through the first and second current sinking branches, which controlling means is coupled between the first and second control inputs;
- and
- an at least DC current measuring means for providing a measure for at least a DC-current in the first current sinking branch, the at least DC current measuring means being coupled between the first control input and the controlling means, the second control input being connected to an output of the controlling means, and the controlling means being arranged to control leading an excessive part of at least the DC-current in the main current stream through the second current sinking branch, the first and second current sinking branches thereby substantially distributing a total current provided to the current distribution circuit.
3 more elements
A current distribution circuit comprising:
- a first current sinking branch, which is provided with a series arrangement of a main current stream of a first controlled semiconductor having a first control input, of a circuit for providing a DC supply voltage, and of a line-current resistor;
- a second current sinking branch connected in parallel to the series arrangement, which second current sinking branch is provided with a second control input, wherein the first and second current sinking branches support at least DC current;
- means for controlling currents through the first and second current sinking branches, which controlling means is coupled to the first and second control inputs;
- and
- an at least DC current measuring means for providing a measure for at least a DC-current in the first current sinking branch,
- the at least DC current measuring means comprising the line-current resistor, and the controlling means being arranged to control, in response to the measure for at least a DC-current in the first current sinking branch, leading an excessive part of at least the DC-current in the main current stream through the second current sinking branch, the first and second current sinking branches thereby substantially distributing a total current provided to the current distribution circuit.
3 more elements
A current distribution circuit comprising:
- a first current sinking branch including a main current stream of a first controlled semiconductor device, said first current sinking branch having a first control input;
- a second current sinking branch connected in parallel to the first current sinking branch, said second current sinking branch having a second control input, said first and second current sinking branches being DC and AC current sinking branches;
- means for controlling DC and AC currents through said first and second current sinking branches, said controlling means being coupled to said first and second control inputs, and
- an at least DC current measuring means coupled to the controlling means for providing a measure for at least a DC-current in said first current sinking branch, said second control input being connected to said controlling means for leading an excessive part of at least said DC-current through the second current sinking branch.
1 more element
Dependencies are inferred from the claim text.