Electricity: power supply or regulation systems – Output level responsive – Using a three or more terminal semiconductive device as the...
Reexamination Certificate
1998-06-18
2001-10-23
Han, Jessica (Department: 2838)
Electricity: power supply or regulation systems
Output level responsive
Using a three or more terminal semiconductive device as the...
C323S283000
Reexamination Certificate
active
06307356
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to voltage regulators. In particular, this invention relates to switch-mode regulators.
Switch-mode regulators, or switching regulators as they are commonly known, are typically used as voltage regulators because they exhibit higher efficiency than an equivalent linear regulator circuit at heavy loads. A typical switching regulator operates by repeatedly turning a power switch fully on and then fully off, generating a pulse-width modulated signal that is averaged to the final voltage with an inductor. Due to the switching nature of the power transistor drive, the efficiency of a typical switch-mode circuit falls off as the load decreases, since a fixed amount of power is wasted in the drive circuitry regardless of load. One method used to avoid this efficiency loss at light loads is to sense the current flowing in the output, and to omit switching cycles when the load is light. This is referred to in this description as Burst Mode™. Stated another way, burst mode is a mode of operation which uses the technique of cycle-skipping to reduce switching losses in a switching regulator and increase the operating efficiency at low output current levels.
Burst mode is relatively easy to implement in a current-feedback regulator, since the output current signal is available to the regulator to allow it to decide when the load is light. A typical voltage feedback switching regulator does not have this load current signal available, and must make the decision to enter burst mode in another manner.
In view of the foregoing, it would be desirable to provide a circuit and a method for enabling a voltage-mode feedback switching regulator to enter and exit burst mode automatically.
It would further be desirable to provide a technique for enabling a voltage-mode feedback switching regulator to enter and exit burst mode automatically for both synchronous and non-synchronous topologies of the voltage-mode feedback switching regulator circuit.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved voltage-mode feedback switching regulator circuit. The circuit can operate in a synchronous or non-synchronous fashion, as well as in step-up or step-down configurations, with minor modifications. The circuit provides a switch circuit having a duty cycle which can be set, a burst mode circuit having a pulse-width modulator generator and a fixed minimum non-zero duty cycle generator, the burst mode circuit being implemented to set the duty cycle of the switch circuit and to determine whether the switch circuit should go into burst mode, and a feedback circuit for receiving a signal from the switch circuit and providing a feedback signal to the burst mode circuit.
REFERENCES:
patent: 3458798 (1969-07-01), Fang et al.
patent: 3571697 (1971-03-01), Phillips
patent: 3579091 (1971-05-01), Clarke et al.
patent: 3581186 (1971-05-01), Weinberger
patent: 3582758 (1971-06-01), Gunn
patent: 3585491 (1971-06-01), Petersen
patent: 3733540 (1973-05-01), Hawkins
patent: 3772588 (1973-11-01), Kelly et al.
patent: 3784893 (1974-01-01), Rando
patent: 3863128 (1975-01-01), Wilwerding
patent: 3879647 (1975-04-01), Hamilton et al.
patent: 3992638 (1976-11-01), Sauvanet
patent: 4013939 (1977-03-01), Biess et al.
patent: 4035710 (1977-07-01), Joyce
patent: 4071884 (1978-01-01), Maigret
patent: 4160288 (1979-07-01), Stuart et al.
patent: 4326245 (1982-04-01), Saleh
patent: 4395675 (1983-07-01), Toumani
patent: 4428015 (1984-01-01), Nesler
patent: 4462069 (1984-07-01), Becky
patent: 4479174 (1984-10-01), Cates
patent: 4493017 (1985-01-01), Kammiller et al.
patent: 4519024 (1985-05-01), Federico et al.
patent: 4541041 (1985-09-01), Park et al.
patent: 4542041 (1985-09-01), Park et al.
patent: 4554499 (1985-11-01), Sherman et al.
patent: 4578630 (1986-03-01), Grosch
patent: 4610521 (1986-09-01), Inoue
patent: 4634956 (1987-01-01), Davis et al.
patent: 4672303 (1987-06-01), Newton
patent: 4672518 (1987-06-01), Murdock
patent: 4674020 (1987-06-01), Hill
patent: 4683529 (1987-07-01), Bucher, II
patent: 4706177 (1987-11-01), Josephson
patent: 4709315 (1987-11-01), Ramos
patent: 4712169 (1987-12-01), Albach
patent: 4716514 (1987-12-01), Patel
patent: 4727308 (1988-02-01), Huljak et al.
patent: 4754385 (1988-06-01), McDade et al.
patent: 4801859 (1989-01-01), Dishner
patent: 4813066 (1989-03-01), Holtz et al.
patent: 4814684 (1989-03-01), McCurdy
patent: 4819122 (1989-04-01), Gontowski, Jr.
patent: 4823070 (1989-04-01), Nelson
patent: 4843532 (1989-06-01), Freedman
patent: 4866587 (1989-09-01), Wadlington
patent: 4870555 (1989-09-01), White
patent: 4884183 (1989-11-01), Sable
patent: 4902957 (1990-02-01), Cassani et al.
patent: 4922404 (1990-05-01), Ludwig et al.
patent: 4928200 (1990-05-01), Redl et al.
patent: 4929882 (1990-05-01), Szepesi
patent: 4931716 (1990-06-01), Jovanovic et al.
patent: 4996638 (1991-02-01), Orr
patent: 5028861 (1991-07-01), Pace et al.
patent: 5034871 (1991-07-01), Okamoto et al.
patent: 5066900 (1991-11-01), Bassett
patent: 5068575 (1991-11-01), Dunsmore et al.
patent: 5081411 (1992-01-01), Walker
patent: 5097196 (1992-03-01), Schoneman
patent: 5128603 (1992-07-01), Wölfel
patent: 5134355 (1992-07-01), Hastings et al.
patent: 5138249 (1992-08-01), Capel
patent: 5144547 (1992-09-01), Masamoto
patent: 5170333 (1992-12-01), Niwayama
patent: 5177676 (1993-01-01), Inam et al.
patent: 5179511 (1993-01-01), Troyk et al.
patent: 5184129 (1993-02-01), Fung et al.
patent: 5193211 (1993-03-01), Nobusawa
patent: 5237606 (1993-08-01), Ziermann
patent: 5309078 (1994-05-01), Cameron
patent: 5396412 (1995-03-01), Barlage
patent: 5408162 (1995-04-01), Williams
patent: 5469349 (1995-11-01), Marinus
patent: 5481178 (1996-01-01), Wilcox et al.
patent: 5528483 (1996-06-01), Mohandes
patent: 5548189 (1996-08-01), Williams
patent: 5568044 (1996-10-01), Bittner
patent: 5627460 (1997-05-01), Bazinet et al.
patent: 5747976 (1998-05-01), Wong et al.
patent: 5804950 (1998-09-01), Hwang et al.
patent: 0 428 377 A2 (1991-05-01), None
patent: 60-32565 (1985-02-01), None
patent: 59-11459 (1985-08-01), None
patent: 60-156269 (1985-08-01), None
patent: 63-307510 (1988-12-01), None
patent: 3-113986 (1991-11-01), None
patent: 2-146080 (1992-02-01), None
patent: 4-42771 (1992-02-01), None
patent: 4-49844 (1992-02-01), None
patent: 4-101286 (1992-09-01), None
patent: 4-128086 (1992-11-01), None
Y.S. Lee and Y.C. Cheng, “Design of Switching Regulator with Combined FM and On-Off Control,”IEEE Transactions on Aerospace and Electronic Systems,vol. AES-22, No. 6, Nov. 1986, pp. 725 to 731.
Jim Williams and Brian Huffman, “Some Thoughts on DC-DC Converters,” Linear Technology Application Note #29, Oct. 1988, pp. AN29-1 to AN29-39.
Jim Williams, “Step Down Switching Regulators,” Linear Technology Application Note #35, Aug. 1989, pp. AN35-1 to AN35-32.
Paul D. Gracie, “Intermittent Converter Saves Power,” EDN Magazine Edition, Sep. 1, 1989, p. 151.
Cassani et al., “Sophisticated Control IC Enhances 1MHz Current Controlled Regulator Performance,” High Frequency Power Conversion 1992, May 1992 Proceedings, pp. 167 to 173.
Maxim Integrated Products Data Book, “Triple-Output Power-Supply Controller for Notebook Computers,” 19-0045, Revision 1; May 1994, pp. 1 to 28.
Williams, J. and Huffman, B., “Proper instrumentation eases low power dc/dc converter design,” EDN, Oct. 27, 1988.
Chryssis, George, “High-frequency Switching Power Supplies,” pp. 144-152 and 180-181, McGraw-Hill, 1989.
Hnatek, Eugene R., “Design of Solid State Power Supplies,” Third Edition, pp. 65-70, Van Nostrand Reinhold, 1989.
Linear Technology, “LT1846/1847, LT3846/3847 Current Mode PWM Controller,” Datasheet, 1990.
Huffman, B., “Efficiency and Power Characteristics of Switching Regulator Circuits,” Application Note 46, Linear Technology, Nov. 1991.
Gold, S., “Design Techniques for Electrostatic Discharge Protection,” Linear Technology, Oct. 1992.
Uitrode, “UC1846/7, UC2846/7, UC38467 Current Mode PWM Controller,” Datasheet, dated Jan. 1997 (date of first publication unknown).
Analog Devices,
Fish & Neave
Han Jessica
Linear Technology Corporation
Morris Robert W.
Weiss Joel
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