Current difference current source
First Claim
1. A circuit for providing a compensated current which is substantially independent of operating condition changes, comprising:
- a first current source comprised of a first transistor and having a first current;
a second current source comprised of a second transistor and coupled serially to said first current source and having a second current;
a third transistor coupled serially to said first current source and parallel to said second current source for providing said compensated current, said compensated current determined by a difference of said first and second currents;
said first and second current sources having characteristics, such that said first and second currents vary as operating conditions change, but said difference remains approximately constant;
whereby a substantially uniform compensated current independant of operating condition variations is achieved.
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Accused Products
Abstract
A current difference current source which provides a stable current as operating conditions change. Two MOS transistors operate as two current sources. A difference current is obtained by subtracting the two transistor currents. The two current sources are configured to vary similarly as conditions change, such that their difference remains constant. In the alternative the difference current is forced to decrease as current increases in the transistors, wherein a reverse compensated current is provided. The difference current is used to drive a current mirror which functions as a compensated current source.
101 Citations
16 Claims
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1. A circuit for providing a compensated current which is substantially independent of operating condition changes, comprising:
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a first current source comprised of a first transistor and having a first current; a second current source comprised of a second transistor and coupled serially to said first current source and having a second current; a third transistor coupled serially to said first current source and parallel to said second current source for providing said compensated current, said compensated current determined by a difference of said first and second currents; said first and second current sources having characteristics, such that said first and second currents vary as operating conditions change, but said difference remains approximately constant; whereby a substantially uniform compensated current independant of operating condition variations is achieved. - View Dependent Claims (2, 3, 4)
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5. A circuit for providing a compensated current which is substantially independent of operating condition changes, comprising:
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a first transistor; a second transistor coupled serially to said first transistor; a third transistor coupled serially to said first transistor and parallel to said second transistor; said compensated current is equivalent to a current flow through said third transistor and is determined by a subtraction of a second transistor current flowing through said second transistor from a first transistor current flowing through said first transistor; whereby said compensated current is substantially uniform as said operating conditions change. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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Specification