Electricity: power supply or regulation systems – Self-regulating – Using a three or more terminal semiconductive device as the...
Reexamination Certificate
2000-10-24
2002-09-03
Berhane, Adolf Deneke (Department: 2838)
Electricity: power supply or regulation systems
Self-regulating
Using a three or more terminal semiconductive device as the...
C323S317000
Reexamination Certificate
active
06445170
ABSTRACT:
FIELD
The present invention relates generally to current references, and more specifically to current references that provide substantially constant current.
BACKGROUND
Current references are circuits that are designed to provide constant current. The constant current is utilized in other circuits, and the design of these other circuits typically relies on the current being constant. One problem with current references is that the current provided can be sensitive to voltage, temperature, and process variations. That is to say, as the voltage, temperature, or process parameters (such as transistor threshold voltages) vary, the current generated by the current reference also varies.
Sensitivity to temperature and power supply voltage variations in current references, and the reduction thereof, has been the subject of much study. See, for example, Sueng-Hoon Lee and Yong Jee, “A Temperature and Supply-Voltage Insensitive CMOS Current Reference,” IEICE Trans. Electron., Vol.E82-C, No.8 August 1999.
Sensitivity to process variations has been historically handled by design margins. For example, if, over expected process variations, a current generated by a current reference can vary by a factor of two, the current reference is typically designed to have a nominal current equal to twice the minimum specified value so that under worst case conditions, the minimum current value is guaranteed to exist. Power is wasted as a result, in part because the nominal current value is twice what is needed.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for a current reference with reduced sensitivity to process variations.
REFERENCES:
patent: 4475077 (1984-10-01), Nagano
patent: 4573168 (1986-02-01), Henze et al.
patent: 4624006 (1986-11-01), Rempfer et al.
patent: 4967140 (1990-10-01), Groeneveld et al.
patent: 5218239 (1993-06-01), Boomer
patent: 5253249 (1993-10-01), Fitzgerald et al.
patent: 5457406 (1995-10-01), Takada et al.
patent: 5490171 (1996-02-01), Epley et al.
patent: 5604450 (1997-02-01), Borkar et al.
patent: 5783936 (1998-07-01), Girard et al.
patent: 5793248 (1998-08-01), Lee et al.
patent: 5841827 (1998-11-01), Chevallier
patent: 6037811 (2000-03-01), Ozguc
patent: 6087847 (2000-07-01), Mooney et al.
patent: 6121764 (2000-09-01), Stockstad
patent: 6133749 (2000-10-01), Hansen et al.
patent: 6150806 (2000-11-01), Canard et al.
patent: 6188237 (2001-02-01), Suzuki et al.
Filanovsky , I.M., “Voltage Reference Using Mutual Compensation of Mobility and Threshold Voltage Temperature Effects”,ISCAS 2000-IEEE International Symposium on Circuits and Systems, V197-V200, (May 28-31, 2000).
Haycock, M., et al., “A 2.5Gb/s Bidirectional Signaling Technology”,Hot Interconnects Symposium V, 1-8, (Aug. 21-23, 1997).
Layton, K., et al., “A CMOS Voltage to Current Converter for Low-Voltage Applications”,AMI Engineering Forum, American Microsystems Inc., http://www.ee.byu.edu/faculty/comerdt/publications.html http://www.ee.byu.edu/faculty/comerdj/publications.html, 13 pages, (Oct. 1999).
Lee, S., et al., “A Temperature and Supply-Voltage Insensitive CMOS Current Reference”,IEICE Trans. Electron, vol. E82-C ,1562-1566, (Aug. 1999).
Martin Aaron K.
Mooney Stephen R.
Narendra Siva G.
Pangal Amaresh
Berhane Adolf Deneke
Intel Corporation
Schwegman Lundberg Woessner & Kluth P.A.
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